January 18, 2025
Nanoscale Viscometry Reveals an Inherent Mucus Defect in Cystic Fibrosis
Olga Ponomarchuk - ,
Francis Boudreault - ,
Ignacy Gryczynski - ,
Bong Lee - ,
Sergei V. Dzyuba - ,
Rafal Fudala - ,
Zygmunt Gryczynski *- ,
John W. Hanrahan - , and
Ryszard Grygorczyk *
The abnormally viscous and thick mucus is a hallmark of cystic fibrosis (CF). How the mutated CF gene causes abnormal mucus remains an unanswered question of paramount interest. Mucus is produced by the hydration of gel-forming mucin macromolecules that are stored in intracellular granules prior to release. Current understanding of mucin/mucus structure before and after secretion remains limited, and contradictory models exist. Here, we used a molecular viscometer and fluorescence lifetime imaging of human bronchoepithelial cells (Normal and CF) to measure nanometer-scale viscosity. We found significantly elevated intraluminal nanoviscosity in a population of CF mucin granules, indicating an intrinsic, presecretory mucin defect. Nanoviscosity influences protein conformational dynamics and function. Its elevation along the protein secretory pathway could arise from molecular overcrowding, impacting mucin’s post-translational processing, hydration, and mucus rheology after release. The nanoviscosity of secreted CF mucus was elevated compared to that of non-CF. Interestingly, it was higher after release than in granules. Validation experiments indicate that reduced mobility of water hydrating mucin macromolecules may contribute to the high nanoviscosity in mucus and mucin granules. This suggests that mucins have a weakly ordered state in granules but adopt a highly ordered, nematic crystalline structure when secreted. This challenges the traditional view of mucus as a porous agarose-like gel and suggests an alternative model for mucin organization before and after secretion. Our study also indicates that endoplasmic reticulum stress due to molecular overcrowding could contribute to mucus pathogenesis in CF cells. It encourages the development of therapeutics that target presecretory mechanisms in CF and other muco-obstructive lung diseases.
Efficient Nitrate to Ammonia Conversion on Bifunctional IrCu4 Alloy Nanoparticles
Ning He - ,
Zhi Yuan - ,
Chao Wu - ,
Shibo Xi - ,
Jingjing Xiong - ,
Yucong Huang - ,
Guanwu Lian - ,
Zefan Du - ,
Laihao Liu - ,
Dawei Wu - ,
Zhongxin Chen *- ,
Wenguang Tu *- ,
Zhigang Zou - , and
Shuk-Yin Tong *
Electrochemical nitrate reduction (NO3RR) to ammonia presents a promising alternative strategy to the traditional Haber–Bosch process. However, the competitive hydrogen evolution reaction (HER) reduces the Faradaic efficiency toward ammonia, while the oxygen evolution reaction (OER) increases the energy consumption. This study designs IrCu4 alloy nanoparticles as a bifunctional catalyst to achieve efficient NO3RR and OER while suppressing the unwanted HER. This is achieved by operating the NO3RR at positive potentials using the IrCu4 catalyst, which allows a Faradaic efficiency of 93.6% for NO3RR. When applied to OER catalysis, the IrCu4 alloy also shows excellent results, with a relatively low overpotential of 260 mV at 10 mA cm–2. Stable ammonia production can be achieved for 50 h in a 16 cm2 flow electrolyzer in simulated working conditions. Our research provides a pathway for optimizing NO3RR through bifunctional catalysts in a tandem approach.
January 17, 2025
Mapping the Energy Carrier Diffusion Tensor in Perovskite Semiconductors
Roberto Brenes - ,
Dane W. deQuilettes *- ,
Richard Swartwout - ,
Abdullah Y. Alsalloum - ,
Osman M. Bakr - , and
Vladimir Bulović *
Understanding energy transport in semiconductors is critical for the design of electronic and optoelectronic devices. Semiconductor material properties, such as charge carrier mobility or diffusion length, are commonly measured in bulk crystals and determined using models that describe transport behavior in homogeneous media, where structural boundary effects are minimal. However, most emerging semiconductors exhibit nano- and microscale heterogeneity. Therefore, experimental techniques with high spatial resolution paired with models that capture anisotropy and domain boundary behavior are needed. We develop a diffusion tensor-based framework to analyze experimental photoluminescence (PL) diffusion maps accounting for material nano- and microstructure. Specifically, we quantify both carrier transport and recombination in single crystal and polycrystalline lead halide perovskites by globally fitting diffusion maps with spatial, temporal, and PL intensity data. We reveal a 29% difference in principal diffusion coefficients and alignment between electronically coupled grains for CH3NH3PbI3 polycrystalline films. This framework allows for understanding and optimizing anisotropic energy transport in heterogeneous materials.
Transforming Medicine: Cutting-Edge Applications of Nanoscale Materials in Drug Delivery
Rumiana Tenchov - ,
Kevin J. Hughes - ,
Magesh Ganesan - ,
Kavita A. Iyer - ,
Krittika Ralhan - ,
Leilani M. Lotti Diaz - ,
Robert E. Bird - ,
Julian M. Ivanov - , and
Qiongqiong Angela Zhou *
This publication is Open Access under the license indicated. Learn More
Since their inception in the early 1960s, the development and use of nanoscale materials have progressed tremendously, and their roles in diverse fields ranging from human health to energy and electronics are undeniable. The application of nanotechnology inventions has revolutionized many aspects of everyday life including various medical applications and specifically drug delivery systems, maximizing the therapeutic efficacy of the contained drugs by means of bioavailability enhancement or minimization of adverse effects. In this review, we utilize the CAS Content Collection, a vast repository of scientific information extracted from journal and patent publications, to analyze trends in nanoscience research relevant to drug delivery in an effort to provide a comprehensive and detailed picture of the use of nanotechnology in this field. We examine the publication landscape in the area to provide insights into current knowledge advances and developments. We review the major classes of nanosized drug delivery systems, their delivery routes, and targeted diseases. We outline the most discussed concepts and assess the advantages of various nanocarriers. The objective of this review is to provide a broad overview of the evolving landscape of current knowledge regarding nanosized drug delivery systems, to outline challenges, and to evaluate growth opportunities. The merit of the review stems from the extensive, wide-ranging coverage of the most up-to-date scientific information, allowing unmatched breadth of landscape analysis and in-depth insights.
Smart Vascular Grafts with Integrated Flow Biosensors for Hemodynamic Real-Time Monitoring and Vascular Healthcare
Zhiqiang Ma *- ,
Jing Zhang *- ,
Shangjie Zou - ,
Ke Huang - ,
Wei Li - ,
Mohamed Elhousseini Hilal - ,
Mingze Zhu - ,
Yatian Fu - , and
Bee Luan Khoo *
Real-time monitoring of hemodynamics is crucial for diagnosing disorders within implanted vascular grafts and facilitating timely treatment. Integrating vascular grafts with advanced flexible electronics offers a promising approach to developing smart vascular grafts (SVGs) capable of continuous hemodynamic monitoring. However, most existing SVG devices encounter significant challenges in practical applications, particularly regarding biomechanical compatibility and the effective evaluation of vascular status. Here, we present a state-of-the-art SVG device seamlessly integrated with flow biosensors constructed by encapsulating patterned porous graphene within biocompatible polymers. The innovative use of porous graphene imparts the SVG with exceptional mechanical sensing performance, featuring a low strain detection limit of 0.0034% and dynamic stability exceeding 32,400 cycles, thus enabling precise hemodynamic perception. This high sensitivity allows the SVG to accurately diagnose vascular disorders, such as blockage degree and position, by collecting hemodynamic data from an artificial artery model. In vitro thrombi (blood clot) diagnostics, treatment simulation experiments, and in vivo tests using a rabbit model strongly validate the SVG’s outstanding and reliable performance in vascular healthcare. We have also developed a stand-alone and wireless system, demonstrating its capability for remote monitoring and managing vascular health. Our pioneering SVG system showcases great potential in vascular healthcare for precise hemodynamic monitoring of disorders, timely diagnostics, and even drug screening.
Understanding the Mechanism of Electrochemical CO2 Capture by Supercapacitive Swing Adsorption
Grace Mapstone - ,
Tim M. Kamsma - ,
Zhen Xu - ,
Penelope K. Jones - ,
Alpha A. Lee - ,
Israel Temprano - ,
James Lee - ,
Michael F. L. De Volder - , and
Alexander C. Forse *
This publication is Open Access under the license indicated. Learn More
Carbon dioxide capture underpins an important range of technologies that can help to mitigate climate change. Improved carbon capture technologies that are driven by electrochemistry are under active development, and it was recently found that supercapacitor energy storage devices can reversibly capture and release carbon dioxide. So-called supercapacitive swing adsorption (SSA) has several advantages over traditional carbon dioxide capture technologies such as lower energy consumption and the use of nontoxic materials. However, the mechanism for the capture of CO2 in these devices is poorly understood, making it challenging to design improved systems. Here, the mechanism of SSA is investigated via finite-element modeling with COMSOL of aqueous continuum transport equations, coupled to the CO2 to bicarbonate reaction. This simple computational model reproduces the key experimental observations and shows that charging leads to bicarbonate depletion (or accumulation) in the electrodes, driving CO2 capture (or release) at the gas-exposed electrode. This suggests that relevant aspects of the mechanism are captured without excluding other mechanisms that might be at play in parallel as well. At very low charging currents, both experiments and modeling reveal a decrease in the amount of carbon dioxide captured, suggesting the presence of competing processes at the two electrodes, and that SSA is an inherently kinetic phenomenon. This study highlights the importance of the operating conditions of these devices and may aid their development in the future.
Tuning Dual Catalytic Active Sites of Pt Single Atoms Paired with High-Entropy Alloy Nanoparticles for Advanced Li-O2 Batteries
Lei Li - ,
Minghao Hua - ,
Jiafeng Li - ,
Peng Zhang - ,
Yingjian Nie - ,
Peng Wang *- ,
Xiaohang Lin - ,
Zhiwei Zhang *- ,
Rutao Wang - ,
Xiaoli Ge *- ,
Yuguang C. Li *- , and
Longwei Yin *
To achieve a long cycle life and high-capacity performance for Li-O2 batteries, it is critical to rationally modulate the formation and decomposition pathway of the discharge product Li2O2. Herein, we designed a highly efficient catalyst containing dual catalytic active sites of Pt single atoms (PtSAs) paired with high-entropy alloy (HEA) nanoparticles for oxygen reduction reaction (ORR) in Li-O2 batteries. HEA is designed with a moderate d-band center to enhance the surface adsorbed LiO2 intermediate (LiO2(ads)), while PtSAs active sites exhibit weak adsorption energy and promote the soluble LiO2 pathway (LiO2(sol)). An optimal ratio between LiO2(ads) and LiO2(sol) pathway was realized to modulate PtSAs and HEA active sites via regulating the etching conditions in the dealloying synthesis process for obtaining high-performance Li-O2 batteries. The ORR kinetics are accelerated, and the parasitic reactions are restrained in the Li-O2 batteries. As a result, Li-O2 batteries based on the HEA@Pt-PtSAs catalyst demonstrate an ultralow overpotential (0.3 V) and ultralong cycling performance of 470 cycles at 1000 mA g–1. The insights into the synthetic strategies and the importance of balancing the ORR pathways will offer guidance for devising multisite synergistic catalysts to accelerate redox-reaction kinetics for Li-O2 batteries.
PEGylated Ultrasmall Iron Oxide Nanoparticles as MRI Contrast Agents for Vascular Imaging and Real-Time Monitoring
Kuan Lu - ,
Ruru Zhang - ,
Hongzhao Wang - ,
Cang Li - ,
Zhe Yang - ,
Keyang Xu - ,
Xiaoyi Cao - ,
Ning Wang - ,
Wu Cai *- ,
Jianfeng Zeng *- , and
Mingyuan Gao *
Accurate imaging evaluations of pre- and post-treatment of cardiovascular diseases are pivotal for effective clinical interventions and improved patient outcomes. However, current imaging methods lack real-time monitoring capabilities with a high contrast and resolution during treatments. This study introduces PEGylated ultrasmall iron oxide nanoparticles (PUSIONPs), which have undergone comprehensive safety evaluations, boasting an r1 value of 6.31 mM–1 s–1, for contrast-enhanced magnetic resonance angiography (MRA). Systematic comparisons against common clinical methods in rabbits reveal that PUSIONPs-enhanced MRA exhibited improved vascular contrast, clearer vascular boundaries, and superior vessel resolution. Moreover, owing to their nanosize, PUSIONPs demonstrate significantly prolonged blood circulation compared to small molecular contrast agents such as Magnevist and Ultravist. This extended circulation enables captivating real-time monitoring of thrombolysis treatment for up to 4 h in rabbit models postsingle contrast agent injection. Additionally, in larger animal models such as beagles and Bama minipigs, PUSIONPs-enhanced MRA also showcases superior contrast effects, boundary delineation, and microvessel visualization, underscoring their potential to transform cardiovascular imaging, particularly in real-time monitoring and high-resolution visualization during treatment processes.
Lactobacillus-Loaded Easily Injectable Hydrogel Promotes Endometrial Repair via Long-Term Retention and Microenvironment Modulation
Guoqing Fan - ,
Yuheng Lu - ,
Yubin Li - ,
Jian Zhang - ,
Yuanbin Wang - ,
Pingyin Lee - ,
Canquan Zhou - ,
Rongkang Huang *- ,
Binghua Ma *- , and
Yuan Yuan *
Regeneration of the injured endometrium, particularly the functional layer, is crucial for the prevention of uterine infertility. At present, clinical treatment using sodium hyaluronate hydrogel injection is limited by its relatively low fluidity, short-term retention, and insufficient bioactive ingredients, so it is necessary to develop an advanced healing-promoting hydrogel. The modulation of the microenvironment by Lactobacillus presents a bioactive component that can facilitate the regeneration of the functional layer. Our study introduces a multifunctional Lactobacillus-loaded poly(N-isopropylacrylamide)-grafted bacterial cellulose (BC-g-PN@L) hydrogel designed with superior injectability and in situ stability. At 25 °C (room temperature), a uniform distribution is achieved with a low injection pressure of only 7.90 kPa. At 37 °C (body temperature), the BC-g-PN@L hydrogel forms a robust three-dimensional nanonetwork, providing space and substance exchange channels for Lactobacillus to maintain its viability and bioactivity. Enhanced by the hydrophobic isopropyl groups in poly(N-isopropylacrylamide) side chains and the rigid bacterial cellulose substrates, the BC-g-PN@L hydrogel exhibits prolonged retention properties in the uterine cavity, persisting for over 21 days. These attributes endow the BC-g-PN@L hydrogel with versatile pro-healing capacity and microenvironment modulation in a rat model of endometrial injury. Our BC-g-PN@L hydrogel promotes the development of advanced injectable hydrogels to facilitate both histological and functional repair of the injured endometrium.
Strong and Fireproof Regenerated Wood via a Combined Phosphorylation-Surface Nanofibrillation and Ionic Cross-Linking Strategy
Wen-Bin Sun - ,
Zi-Meng Han - ,
Xiao-Han Luo - ,
Huai-Bin Yang - ,
Zhao-Xiang Liu - ,
De-Han Li - ,
Kun-Peng Yang - ,
Qing-Fang Guan *- , and
Shu-Hong Yu *
To reduce the environmental impact of plastics, an increasing number of high-performance sustainable materials have emerged. Among them, wood-based high-performance structural materials have gained growing attention due to their outstanding mechanical and thermal properties. Here, we introduce phosphate groups onto the wood veneers for surface nanofibrillation, effectively altering both the molecular structure and surface morphology of wood, which enhances the interactions between wood veneers and endows the wood with excellent fire resistance properties. With these phosphorylated wood-based building blocks, “chemical welding” structural materials (CWSMs) obtained through chemical cross-linking exhibit excellent mechanical properties. The flexural strength of CWSM reaches 225 MPa, and the modulus reaches 16 GPa, surpassing those of various types of natural wood. At the same time, phosphorylation has endowed CWSM with excellent fire resistance, with a limiting oxygen index reaching 49%, making it completely noncombustible. More importantly, as a biomass-based structural material, CWSM exhibits mechanical, thermal, and fire resistance properties and degradability far superior to those of traditional petroleum-based plastics, making it an ideal candidate for plastic replacement.
Biofluid-Permeable and Erosion-Resistant Wireless Neural-Electronic Interfaces for Neurohomeostasis Modulation
Zhidong Wei - ,
Fei Jin - ,
Tong Li - ,
Yuyuan He - ,
Lili Qian - ,
Juan Ma - ,
Tao Yuan - ,
Xin Yu - ,
Weiying Zheng - ,
Negar Javanmardi - ,
Esteban Pena-Pitrach - ,
Ting Wang *- ,
Jianda Xu *- , and
Zhang-Qi Feng *
Neural-electronic interfaces through delivering electroceuticals to lesions and modulating pathological endogenous electrical environments offer exciting opportunities to treat drug-refractory neurological disorders. Such an interface should ideally be compatible with the neural tissue and aggressive biofluid environment. Unfortunately, no interface specifically designed for the biofluid environments is available so far; instead, simply stacking an encapsulation layer on silicon-based substrates makes them susceptible to biofluid leakage, device malfunction, and foreign-body reactions. Here, we developed a biofluid-permeable and erosion-resistant wireless neural-electronic interface (BNEI) that is composed of a flexible 3D interconnected poly(l-lactide) fibrous network with a dense and axially aligned piezoelectrical molecular chain arrangement architecture. The organized molecular chain structure enhances the tortuous pathway and longitudinal piezoelectric coefficient of poly(l-lactide) fibers, improves their water barrier properties, and enables efficient conversion of low-intensity acoustic vibrations transmitted in biofluids into electrical signals, achieving long-term stable and wireless neuromodulation. A 3-month clinical trial demonstrated that the BNEI can effectively accelerate the pathological cascade in peripheral neuropathy for nerve regeneration and transcranially modulate cerebellar–cerebral circuit dynamics, suppressing seizures in temporal lobe epilepsy. The BNEI can be a clinically scalable approach for wireless neuromodulation that is broadly applicable to the modulation of neurohomeostasis in both the peripheral and central nervous systems.
Targeted Modulation of the Meningeal Lymphatic Reverse Pathway for Immunotherapy of Breast Cancer Brain Metastases
Yanfeng Dai - ,
Xiang Yu - ,
Yifan Zhao - ,
Jianshuang Wei - ,
Dong Lin - ,
Jialu Wang - ,
Ren Zhang - ,
Xuenan Yuan - ,
Sanmu Li - ,
Songlin Huang - ,
Qian Liu *- , and
Zhihong Zhang *
Treatment of tumor brain metastases remains challenging due to the ineffectiveness of drugs in crossing the blood–brain barrier (BBB). Here, we proposed a potential strategy to target and modulate the meningeal lymphatic system for immunotherapy of breast cancer brain metastases (BCBM) through peripheral administration. CT/fluorescence dual-modality imaging demonstrated that the phospholipid nanoprobe (α-PLNPs) through intracisternal magna injection effectively labeled and long-range tracked the meningeal lymphatic pathway from meningeal lymphatic vessels (MLVs) to periphery drainage cervical lymph nodes (CLNs). Interestingly, the reverse pathway from CLNs to MLVs was also successfully labeled with α-PLNPs through cervical subcutaneous injection, facilitating the noninvasive delivery of immunomodulators to the meningeal lymphatics. Given this, we used melittin-carrying α-M-PLNPs to trigger the modulation of the meningeal lymphatic reverse pathway, which effectively prevents BCBM and prolongs the survival of mice through activating the antigen-presenting cells in the CLNs and promoting the migration of CD8+ T cells into the metastatic brain tumors. This study highlights the potential of the meningeal lymphatic reverse pathway for the immunotherapy of BCBM, which holds great promise for central nervous system disease therapy without the need for drug delivery via BBB.
Complex Core–Shell Architectures through Spatially Organized Nano-Assemblies
Xiangyu Jiang - ,
Bo Jiang - ,
Manrui Mu - ,
Tongyi Wang - ,
Shi Sun - ,
Jiaxin Xu - ,
Shutao Wang - ,
Yan Zhou - ,
Jun Zhang - , and
Wenle Li *
Core–shell structures demonstrate superior capability in customizing properties across multiple scales, offering valuable potential in catalysis, medicine, and performance materials. Integrating functional nanoparticles in a spatially controlled manner is particularly appealing for developing sophisticated architectures that support heterogeneous characteristics and tandem reactions. However, creating such complex structures with site-specific features remains challenging due to the dynamic microenvironment during the shell-forming process, which considerably impacts colloidal particle assembly. Here, we describe a method to spatially deploy nanoscale assemblies within microscale structures comprising a dense shell and a liquid core through colloidal surface decoration coupled with emulsion-based synthesis. Exploiting a spectrum of nanoparticles grafted with incrementally varying densities of organic ligands, we reveal that nanofeatures can be selectively sculpted onto the shell exterior, within the shell wall, and on the interior surface. The versatility of this mechanism is validated by systematically arranging nanoparticles with various compositions, shapes, and dimensions. Spatially integrated nanotitania endows the core–shell structures with localized photocatalytic abilities. Additionally, distinctive surface modifications enable the simultaneous yet independent implantation of diverse nanoparticles, yielding intricate architectures with programmable functions. This generalizable approach showcases a synthetic strategy to attain structural complexity and functional sophistication reminiscent of those of biological systems in nature.
Biomimetic Confined Assembly of Plasmonic CuS from Electronic Waste for Rapid Photothermal Disinfection
Zewei Hao - ,
Jingyu Sun - ,
Jiabin Chen *- ,
Yinchuan Yang - ,
Xiaoqi Sun - ,
Ruicheng Ji - ,
Qipeng Zhao - ,
Xuefei Zhou - ,
Hongbo Zeng - , and
Yalei Zhang *
Photothermal disinfection (PTD) offers promising potential for water purification due to its sustainable and broad-spectrum bactericidal properties, although it is hindered by slow charge separation in photosensitizers. Herein, we present a plasma-mediated PTD technique utilizing an efficient localized heating effect induced by incident light at specific wavelengths for rapid bacterial inactivation. A metallic CuS photosensitizer, derived from electronic waste through a biomimetic transmembrane confined-assembled strategy, facilitates collective and coherent oscillation of free electrons around Cu atoms in the near-infrared range. The resulting plasmon resonance effect generates abundant high-energy hot carriers, further enhancing the separation efficiency of carriers generated by plasmon-induced intrinsic excitation. The nonradiative dissipation of these carriers triggers a significant localized heating effect in water matrices, leading to comprehensive PTD performance against E. coli and B. subtilis. This study highlights the role of the plasmonic heating effect from waste-derived photosensitizers in enhancing PTD performance, inspiring the development of advanced water disinfection technologies.
January 16, 2025
Two-Dimensional Tantalum Carbo-Selenide for Hydrogen Evolution
Elham Loni - ,
Ahmad Majed - ,
Shengjie Zhang - ,
Hari H. S. Thangavelu - ,
Chaochao Dun - ,
Anika Tabassum - ,
Karamullah Eisawi - ,
Jeffrey J. Urban - ,
Per O. Å. Persson - ,
Matthew M. Montemore - , and
Michael Naguib *
This publication is Open Access under the license indicated. Learn More
Herein, we report the synthesis of two-dimensional Ta2Se2C (2D-Ta2Se2C) nanosheets using electrochemical lithiation in multilayer Ta2Se2C followed by sonication in deionized water. Multilayer Ta2Se2C was obtained via solid-state synthesis of FexTa2Se2C followed by chemical etching of Fe. 2D-Ta2Se2C exhibited promising electrocatalytic activity for the hydrogen evolution reaction from water compared to multilayer Ta2Se2C and 2D-TaSe2. 2D-Ta2Se2C showed an overpotential at 10 mA·cm–2 (η10) of 264 mV, a Tafel slope of 91 mV·dec–1, and an electrochemically active surface area of 17.61 mECSA2·gcatalyst–1. The high performance could be attributed to the large surface area of single sheets which hence maximizes the number of exposed catalytic sites and increased density of vacancies, observed with transmission electron microscopy, during synthesis and processing.
Bacterial Nanovesicles as Interkingdom Signaling Moieties Mediating Pain Hypersensitivity
Sameh Almousa - ,
Susy Kim - ,
Ashish Kumar - ,
Yixin Su - ,
Sangeeta Singh - ,
Shalini Mishra - ,
Miriam M. Fonseca - ,
Hilal A. Rather - ,
E. Alfonso Romero-Sandoval - ,
Fang-Chi Hsu - ,
Rakesh Singh - ,
Hariom Yadav - ,
Santosh Mishra - , and
Gagan Deep *
Gut dysbiosis contributes to multiple pathologies, yet the mechanisms of the gut microbiota-mediated influence on systemic and distant responses remain largely elusive. This study aimed to identify the role of nanosized bacterial extracellular vesicles (bEVs) in mediating allodynia, i.e., pain hypersensitivity, in a diet-induced obesity (DIO) gut dysbiosis model. bEVs were enriched from the feces of lean (bEVLean) and DIO (bEVDIO) mice by an approach combining ultracentrifugation and immunoprecipitation and then extensively analyzed for purity and bacterial characteristics. Next, bEVs were injected, either intraplantarly or intravenously, in mice to assess pain sensitivity. Fluorescence-labeled bEVs were injected in mice by enema to assess biodistribution. The effect of bEV on immune cells and inflammation was analyzed by array, immunophenotyping, microscopy, NF-κB activation, and cellular uptake assays. Results showed that bEVDIO administration in wild-type mice replicated the allodynia phenotype observed in DIO mice for both mechanical and thermal stimuli. Importantly, this effect was compromised in TRPA1/TRPV1 double-knockout mice. Biodistribution analyses showed bEV entry into systemic circulation with subsequent localization at distant sites. Multiple analyses revealed that bEVDIO exposure incited systemic inflammation, primarily through modulating the innate immune system. This inflammatory mechanism involved LPS on the bEV surface, activating TLR2- and TLR4-related pathways, as confirmed using TLR2 and TLR4 inhibitors and shaving bEV surface proteins. Interestingly, the enhanced cellular uptake of bEVDIO was contingent on interactions involving LPS and proteins on bEVs and TLR2/TLR4 on monocytes. These findings illuminate the hitherto unexplored role of bEV as pivotal mediators of allodynia and inflammation linked to gut dysbiosis.
Personalized Nanovaccine Based on STING-Activating Nanocarrier for Robust Cancer Immunotherapy
Yongjuan Li - ,
Ya Dong - ,
Danyang Shen - ,
Yichen Guo - ,
Yongjian Cao - ,
Kaixin Zhang - ,
Xinyan Li - ,
Rongrong Zhu - ,
Jinmeng Yi - ,
Xiaohan Yao - ,
Xiaowei Dang - ,
Rui Li - ,
Zhenzhong Zhang *- ,
Zhihai Qin *- , and
Weijing Yang *
Tumor-specific T cells play a vital role in potent antitumor immunity. However, their efficacy is severely affected by the spatiotemporal orchestration of antigen-presentation as well as the innate immune response in dendritic cells (DCs). Herein, we develop a minimalist nanovaccine that exploits a dual immunofunctional polymeric nanoplatform (DIPNP) to encapsulate ovalbumin (OVA) via electrostatic interaction when the nanocarrier serves as both STING agonist and immune adjuvant in DCs. In vitro results reveal that the nanocarrier induces STING activation via facilitating interferon regulatory factor 3 phosphorylation by block poly 18-crown-6-yl methacrylate (P18C6MA) mediated K+ perturbation cascade with endoplasmic reticulum stress, and stimulates DC maturation via the Toll-like receptor 4 activation by primary amine. In vivo studies indicate that the smart nanovaccine dramatically inhibits tumor growth with a long-term immune memory response in both the B16-OVA and EG7-OVA tumor models. After combination with programmed death ligand-1 antibody (aPD-L1), mice survival rate is notably prolonged. In addition, DIPNP forms a personalized nanovaccine after resected autologous primary tumor cell membranes decoration with a high antitumor activity in a homologous distant tumor model. The rational design provides inspiration for personalized nanovaccine construction via immunofunctional nanocarriers.
Low-Frequency Resistance Noise in Near-Magic-Angle Twisted Bilayer Graphene
Pritam Pal *- ,
Saisab Bhowmik - ,
Aparna Parappurath - ,
Saloni Kakkar - ,
Kenji Watanabe - ,
Takashi Taniguchi - , and
Arindam Ghosh *
The low-frequency resistance fluctuations, or noise, in electrical resistance not only set a performance benchmark in devices but also form a sensitive tool to probe nontrivial electronic phases and band structures in solids. Here, we report the measurement of such noise in the electrical resistance in twisted bilayer graphene (tBLG), where the layers are misoriented close to the magic angle (θ ∼ 1°). At high temperatures (T ≳ 60–70 K), the power spectral density (PSD) of the fluctuation inside the low-energy moiré bands is predominantly ∝1/f, where f is the frequency, being generally lowest close to the magic angle, and can be well-explained within the conventional McWhorter model of the ‘1/f noise’ with trap-assisted density-mobility fluctuations. At low T (≲10 K), the measured noise exhibits a strong two-level random telegraphic signal (RTS), especially close to the moiré gap, which exhibits a ∝1/f2-like PSD that can be attributed to poorly screened resonances of the Fermi energy to specific bands of defects in the encapsulating boron nitride (hBN) layers. The low-T noise within the moiré band exhibits a series of minima at the integral as well as half-integral fillings, which align with the frequently observed van Hove singularities in the density-of-states driven by strong Coulomb interaction. Apart from providing a comprehensive account of the origin and the magnitude of noise in tBLG, our experiment also reveals noise to be significantly more sensitive to the underlying interaction effects in tBLG than the conventional time-averaged transport.
Downscaling of Non-Van der Waals Semimetallic W5N6 with Resistivity Preservation
Hongze Gao - ,
Da Zhou - ,
Lu Ping - ,
Zifan Wang - ,
Nguyen Tuan Hung - ,
Jun Cao - ,
Michael Geiwitz - ,
Gabriel Natale - ,
Yuxuan Cosmi Lin - ,
Kenneth Stephen Burch - ,
Riichiro Saito - ,
Mauricio Terrones - , and
Xi Ling *
The bulk phase of transition metal nitrides (TMNs) has long been a subject of extensive investigation due to their utility as coating materials, electrocatalysts, and diffusion barriers, attributed to their high conductivity and refractory properties. Downscaling TMNs into two-dimensional (2D) forms would provide valuable members to the existing 2D materials repertoire, with potential enhancements across various applications. Moreover, calculations have anticipated the emergence of uncommon physical phenomena in TMNs at the 2D limit. In this study, we use the atomic substitution approach to synthesize 2D W5N6 with tunable thicknesses from tens of nanometers down to 2.9 nm. The obtained flakes exhibit high crystallinity and smooth surfaces. Electrical measurements on 15 samples show an average electrical conductivity of 161.1 S/cm, which persists while thickness decreases from 45.6 to 2.9 nm. The observed weak gate-tuning effect suggests the semimetallic nature of the synthesized 2D W5N6. Further investigation of the conversion mechanism elucidates the crucial role of chalcogen vacancies in the precursor for initiating the reaction and strain in propagating the conversion. Our work introduces a desired semimetallic crystal to the 2D material library with mechanistic insights for future design of the synthesis.
MXene Hollow Microsphere-Boosted Nanocomposite Electrodes for Thermocells with Enhanced Thermal Energy Harvesting Capability
Zhaopeng Liu - ,
Dianlun Wu - ,
Shouhao Wei - ,
Kangqian Xing - ,
Meilin Li - ,
Yue Jiang - ,
Rongfeng Yuan - ,
Guangming Chen - ,
Zhe Hu *- ,
Yang Huang *- , and
Zhuoxin Liu *
Thermal energy, constantly being produced in natural and industrial processes, constitutes a significant portion of energy lost through various inefficiencies. Employing the thermogalvanic effect, thermocells (TECs) can directly convert thermal energy into electricity, representing a promising energy-conversion technology for efficient, low-grade heat harvesting. However, the use of high-cost platinum electrodes in TECs has severely limited their widespread adoption, highlighting the need for more cost-effective alternatives that maintain comparable thermoelectrochemical performance. In this study, a nanocomposite electrode featuring Ti3C2Tx with hollow microsphere structures is rationally designed. This design addresses the restacking issue inherent in MXene nanosheets, increases the electrochemically active surface area, and modifies the original MXene surfaces with oxygen terminations, leading to improved redox kinetics at the electrode–electrolyte interface, particularly in n-type TECs employing Fe2+/3+ redox ions. The optimized n-type TEC achieved an output power of 84.55 μW cm–2 and a normalized power density of 0.53 mW m–2 K–2 under a ΔT of 40 K, outperforming noble platinum-based TECs by a factor of 5.5. An integrated device consisting of 32 TEC units with a p–n connection is also fabricated, which can be successfully utilized to power various small electronics. These results demonstrate the potential of MXene-based composite electrodes to revolutionize TEC technology by offering a cost-effective, high-performance alternative to traditional noble metal electrodes and contributing to efficient low-grade heat harvesting.
Framework Nucleic Acid-Based and Neutrophil-Based Nanoplatform Loading Baicalin with Targeted Drug Delivery for Anti-Inflammation Treatment
Mi Zhou - ,
Yuanlin Tang - ,
Yifei Lu - ,
Tianxu Zhang - ,
Shunhao Zhang - ,
Xiaoxiao Cai - , and
Yunfeng Lin *
Targeted drug delivery is a promising strategy for treating inflammatory diseases, with recent research focusing on the combination of neutrophils and nanomaterials. In this study, a targeted nanodrug delivery platform (Ac-PGP-tFNA, APT) was developed using tetrahedral framework nucleic acid (tFNA) along with a neutrophil hitchhiking mechanism to achieve precise delivery and anti-inflammatory effects. The tFNA structure, known for its excellent drug-loading capacity and cellular uptake efficiency, was used to carry a therapeutic agent─baicalin. The results demonstrate that the development of this drug delivery platform not only considerably enhances the bioavailability and effective concentration of the drug (baicalin) but also promotes the polarization of pro-inflammatory M1 macrophages to anti-inflammatory M2 macrophages by modulating the interactions between the neutrophils and macrophages. This targeted therapeutic method effectively treats inflammatory conditions such as sepsis and introduces a strategy for managing inflammatory diseases characterized by neutrophil infiltration.
Asymmetric Atomic Coordination of Platinum Skin Layer on Intermetallic Platinum–Cobalt Particles
Shunsuke Kobayashi *- ,
Yuki Omori - ,
Kei Nakayama - ,
Kousuke Ooe - ,
Hsin-Hui Huang - , and
Akihide Kuwabara *
Pt-based intermetallic alloy particles with a Pt skin layer have higher catalytic activity than solid-solution alloy particles and have attracted considerable attention for practical applications in polymer electrolyte fuel cells. However, the reason for the superior performance of intermetallic alloys is not yet fully understood. Because the catalytic reaction proceeds on the topmost surface of the particle, it is necessary to clarify the relationship between the periodic structure of the intermetallic alloy and the Pt atomic coordination on the surface. This study investigated the Pt–Pt interatomic distance of a Pt skin layer formed on intermetallic Pt3Co particles at atomic resolution through precise measurements using scanning transmission electron microscopy and theoretical calculations. The Pt atomic coordination on the surface shows good agreement between experimental observations and theoretical models, although the experimental image is a projection and thus provides indirect results. The theoretical calculation model revealed that structural relaxation at the Pt and Pt3Co interfaces led to two distinct Pt bonding states at the surface, including asymmetric atomic coordination. The asymmetric coordination of the Pt site deepens the d-band center, diversifies the oxygen adsorption energies, and enhances catalytic activity. Further exploration and control of the unique surface Pt coordination environments formed on the periodic structures of intermetallic alloys should reveal promising routes for the development of catalytic particles.
Enhancing Droplet Spreading on a Hydrophobic Plant Surface by Surfactant/Cellulose Nanocrystal Complexes
Gaili Cao - ,
Weinan Zhao - ,
Lian Han - ,
Youchao Teng - ,
Shikuan Xu - ,
Han Nguyen - , and
Kam Chiu Tam *
A surfactant is an efficient and common additive used to enhance the spreading of droplets on hydrophobic surfaces. However, a high surfactant concentration is required to achieve the desired performance, resulting in environmental pollution and increased costs. Additionally, the pesticide loading capacity of surfactants at low concentrations (below their critical micelle concentrations) is a concern. Thus, in this study, we developed a strategy to enhance pesticide loading and droplet deposition by mixing small amounts of sodium dodecyl sulfate (SDS) (0.1 wt %) and cationically modified cellulose nanocrystals (PCNC). The reduced surface tension, increased viscosity and adhesion, and electrostatic and hydrogen interactions resulted in a low retraction velocity, excellent spreading, and resistance to air turbulence. The improved loading content was facilitated by the hydrophobic domains of PCNC and SDS micelles.
Molecular Determinants of Optical Modulation in ssDNA–Carbon Nanotube Biosensors
Andrew T. Krasley - ,
Sayantani Chakraborty - ,
Lela Vuković *- , and
Abraham G. Beyene *
This publication is Open Access under the license indicated. Learn More
Most traditional optical biosensors operate through molecular recognition, where ligand binding causes conformational changes that lead to optical perturbations in the emitting motif. Optical sensors developed from single-stranded DNA-functionalized single-walled carbon nanotubes (ssDNA–SWCNTs) have started to make useful contributions to biological research. However, the mechanisms underlying their function have remained poorly understood. In this study, we combine experimental and computational approaches to show that ligand binding alone is not sufficient for optical modulation in this class of synthetic biosensors. Instead, the optical response that occurs after ligand binding is highly dependent on the chemical properties of the ligands, resembling mechanisms seen in activity-based biosensors. Specifically, we show that in ssDNA–SWCNT catecholamine sensors, the optical response correlates positively with the electron density on the aryl motif, even among ligands with similar ligand binding affinities. Importantly, despite the strong correlations with electrochemical properties, we find that catechol oxidation itself is not necessary to drive the sensor optical response. We discuss how these findings could serve as a framework for tuning the performance of existing sensors and guiding the development of new biosensors of this class.
Silica-Activated Redox Signaling Confers Rice with Enhanced Drought Resilience and Grain Yield
Zhao Kang - ,
Jiankang Lu - ,
Shourong Zheng - ,
Xiaojie Hu - ,
Lianhong Wang - ,
Lijuan Jiang - ,
Yuqi Zheng - ,
Lecheng Lv - ,
Jorge L. Gardea-Torresdey - ,
Jason C. White - , and
Lijuan Zhao *
Under a changing climate, enhancing the drought resilience of crops is critical to maintaining agricultural production and reducing food insecurity. Here, we demonstrate that seed priming with amorphous silica (SiO2) nanoparticles (NPs) (20 mg/L) accelerated seed germination speed, increased seedlings vigor, and promoted seedling growth of rice under polyethylene glycol (PEG)-mimicking drought conditions. An orthogonal approach was used to uncover the mechanisms of accelerated seed germination and enhanced drought tolerance, including electron paramagnetic resonance, Fourier transform infrared spectroscopy (FTIR), metabolomics, and transcriptomics. It was revealed that the unique surface chemistry of amorphous silica, characterized by an enrichment of silanol and siloxane groups, can catalyze the production of reactive oxygen species. This, in turn, initiates redox signaling and activates downstream drought-responsive genes. In addition, silica-primed seeds exhibited a significant enrichment of 18 amino acids and 6 sugars compared to those undergoing hydropriming, suggesting the accelerated mobilization of stored energy reserves. The drought-tolerance trait was observed in vegetative tissues of 35 day-old plants, where this tolerance was associated with an accelerated catabolism of amino acids and an enhanced anabolism of antioxidants. A separated field trial showed that SiO2NPs seed priming not only increased rice grain yield by 7.77% (p = 0.051) and 6.48% (p = 0.066), respectively, under normal and drought conditions but also increased the grain amino acid content. These results demonstrate that a simple and cost-effective nanoseed-priming approach can convey life cycle-long drought tolerance while simultaneously increasing rice grain yield and nutrition quality, providing an effective and sustainable strategy to cultivate climate-resilient crops.
Concentration-Dependent Control of the Band Gap Energy of a Low-Dimensional Lepidocrocite Titanate
Adam D. Walter - ,
Gregory R. Schwenk *- ,
Yuanren Liu - ,
David Bugallo Ferron - ,
Jeffrey T. Wilk - ,
Lucas M. Ferrer - ,
Christopher Y. Li - ,
Yong-Jie Hu - , and
Michel W. Barsoum *
This publication is Open Access under the license indicated. Learn More
Recently, we reported on the simple, scalable synthesis of quantum-confined one-dimensional (1D) lepidocrocite titanate nanofilaments (1DLs). Herein, we show, using solid-state UV–vis spectroscopy, that reducing the concentration of aqueous 1DL colloidal suspensions from 40 to 0.01 g/L increases the band gap energy and light absorption onset of dried filtered films from ≈3.5 to ≈4.5 eV. This range is ascribed to quantum confinement as the system transitions from two-dimensional (2D) into 1D with dilution. It is only after the colloidal suspensions are dried and the 1DLs start to self-assemble into ribbons and sheets that the band gap values change. This self-assembly is manifested in the X-ray diffraction patterns and the emergence of a Raman band characteristic of 2D lepidocrocite titanates. In colloidal form, 1DLs exhibit a lyotropic liquid crystal phase with a critical concentration of between 10 and 1 g/L. Additionally, the Beer–Lambert law applies with a mass absorbance coefficient of 2 ± 0.4 Lg–1 cm–1. The optical absorbance edges of the colloidal suspensions are not a function of concentration. The experimental findings are theoretically supported by density functional theory calculations of the Raman vibrational modes and electronic band structures of the 1D and 2D lepidocrocite titanate atomic structures.
January 15, 2025
Anchoring of Probiotic-Membrane Vesicles in Hydrogels Facilitates Wound Vascularization
Chen Zhou - ,
Hongfu Cao - ,
Yuxiang Wang - ,
Chong Yao - ,
Yaping Zou - ,
Jingyi Liu - ,
Na Li - ,
Tun Yuan - ,
Jie Liang - ,
Qiguang Wang *- ,
Yujiang Fan *- , and
Xingdong Zhang
Inadequate vascularization significantly hampers wound recovery by limiting nutrient delivery. To address this challenge, we extracted membrane vesicles from Lactobacillus reuteri (LMVs) and identified their angiogenic potential via transcriptomic analysis. We further developed a composite hydrogel system (Gel-LMVs) by anchoring LMVs within carboxylated chitosan and cross-linking it with oxidized hyaluronic acid through a Schiff base reaction. The resulting Gel-LMVs exhibit good biocompatibility and retain the bioactivity of LMVs, which are released in a controlled manner to stimulate cell proliferation, migration, and angiogenesis in vitro by modulating gene expression in critical signaling pathways. Moreover, in an in vivo model, Gel-LMVs upregulate vascular endothelial growth factor (VEGF) and platelet endothelial cell adhesion molecule (CD31), leading to accelerated vascularization in early healing stages, while concurrently reducing inflammation and augmenting collagen deposition to enhance wound healing quality. This approach to functionalizing biomaterials with probiotic-MVs offers an advanced strategy for wound healing.
Multifunctional Nanomedicine for Targeted Atherosclerosis Therapy: Activating Plaque Clearance Cascade and Suppressing Inflammation
Cui Tang - ,
Hui Wang - ,
Lina Guo - ,
Yimin Cui - ,
Chan Zou - ,
Jianming Hu - ,
Hanyong Zhang - ,
Guoping Yang *- , and
Wenhu Zhou *
Atherosclerosis (AS) is a prevalent inflammatory vascular disease characterized by plaque formation, primarily composed of foam cells laden with lipids. Despite lipid-lowering therapies, effective plaque clearance remains challenging due to the overexpression of the CD47 molecule on apoptotic foam cells, inhibiting macrophage-mediated cellular efferocytosis and plaque resolution. Moreover, AS lesions are often associated with severe inflammation and oxidative stress, exacerbating disease progression. Herein, we introduce a multifunctional nanomedicine (CEZP) targeting AS pathogenesis via a “cell efferocytosis–lipid degradation–cholesterol efflux” paradigm, with additional anti-inflammatory properties. CEZP comprises poly(lactic-co-glycolic acid) nanoparticles encapsulated within a metal–organic framework shell coordinated with zinc ions (Zn2+) and epigallocatechin gallate (EGCG), enabling CpG encapsulation. Upon intravenous administration, CEZP accumulates at AS plaque sites, facilitating macrophage uptake and orchestrating AS treatment through synergistic mechanisms. CpG enhances cellular efferocytosis, Zn2+ promotes intracellular lipid degradation, and EGCG upregulates adenosine 5′-triphosphate-binding cassette transporters for cholesterol efflux while also exhibiting antioxidant and anti-inflammatory effects. In vivo validation confirms CEZP’s ability to stabilize plaques, reduce lipid burden, and modulate the macrophage phenotype. Moreover, CEZP is excreted from the body without safety concerns, offering a low-toxicity nonsurgical strategy for AS plaque eradication.
Long-Range Charge Transport Facilitated by Electron Delocalization in MoS2 and Carbon Nanotube Heterostructures
Daria D. Blach - ,
Dana B. Sulas-Kern - ,
Bipeng Wang - ,
Run Long - ,
Qiushi Ma - ,
Oleg V. Prezhdo - ,
Jeffrey L. Blackburn - , and
Libai Huang *
This publication is Open Access under the license indicated. Learn More
Controlling charge transport at the interfaces of nanostructures is crucial for their successful use in optoelectronic and solar energy applications. Mixed-dimensional heterostructures based on single-walled carbon nanotubes (SWCNTs) and transition metal dichalcogenides (TMDCs) have demonstrated exceptionally long-lived charge-separated states. However, the factors that control the charge transport at these interfaces remain unclear. In this study, we directly image charge transport at the interfaces of single- and multilayered MoS2 and (6,5) SWCNT heterostructures using transient absorption microscopy. We find that charge recombination becomes slower as the layer thickness of MoS2 increases. This behavior can be explained by electron delocalization in multilayers and reduced orbital overlap with the SWCNTs, as suggested by nonadiabatic (NA) molecular dynamics (MD) simulations. Dipolar repulsion of interfacial excitons results in rapid density-dependent transport within the first 100 ps. Stronger repulsion and longer-range charge transport are observed in heterostructures with thicker MoS2 layers, driven by electron delocalization and larger interfacial dipole moments. These findings are consistent with the results from NAMD simulations. Our results suggest that heterostructures with multilayer MoS2 can facilitate long-lived charge separation and transport, which is promising for applications in photovoltaics and photocatalysis.
Atomic-Level Stoichiometry Control of Ferroelectric HfxZryOz Thin Films by Understanding Molecular-Level Chemical Physical Reactions
Ngoc Le Trinh - ,
Bonwook Gu - ,
Kun Yang - ,
Chi Thang Nguyen - ,
Byungchan Lee - ,
Hyun-Mi Kim - ,
Hyeongkeun Kim - ,
Youngho Kang - ,
Min Hyuk Park *- , and
Han-Bo-Ram Lee *
HfO2-based thin films have garnered significant interest for integrating robust ferroelectricity into next-generation memory and logic chips, owing to their applicability with modern Si device technology. While numerous studies have focused on enhancing ferroelectric properties and understanding their fundamentals, the fabrication of ultrathin HfO2-based ferroelectric films has seldom been reported. This study presents the concept of atomic-level stoichiometry control of ferroelectric HfxZryOz films by examining the molecular-level interactions of precursor molecules in the atomic layer deposition (ALD) process through theoretical calculations. Atomic layer modulation (ALM) employs sequential precursor pulses, and the stoichiometries of HfxZryOz films are determined by the chemical and physical reactions predicted by theoretical simulations. The HfxZryOz ALM films demonstrate superior crystallinity and ferroelectricity compared to conventional HfxZryOz ALD films, with large polarization values reaching 2Pr = 48.8 μC/cm2 at a thickness of 4.5 nm. Because the ALM concept combines experimental and theoretical approaches, it can be applied to other applications that require multicomponent thin films with atomic-level stoichiometry control.
Exploring the Activation of Atomically Precise [Pt17(CO)12(PPh3)8]2+ Clusters: Mechanism and Energetics in Gas Phase and on an Inert Surface
Papri Chakraborty - ,
Marco Neumaier - ,
Johannes Seibel - ,
Nicola Da Roit - ,
Artur Böttcher - ,
Christian Schmitt - ,
Di Wang - ,
Christian Kübel - ,
Silke Behrens - , and
Manfred M. Kappes *
Atomically precise clusters such as [Pt17(CO)12(PPh3)8]x+ (x = 1,2) (PPh3 is triphenylphosphine) are known as precursors for making oxidation catalysts. However, the changes occurring to the cluster upon thermal activation during the formation of the active catalyst are poorly understood. We have used a combination of hybrid mass spectrometry and surface science to map the thermal decomposition of [Pt17(CO)12(PPh3)8](NO3)2. High-resolution mass and ion mobility spectrometry together with DFT-based modeling were used to probe the sequence of fragmentation reactions and fragment structures generated upon collisional excitation of [Pt17(CO)12(PPh3)8]2+. This was compared with thermal desorption spectroscopy of [Pt17(CO)12(PPh3)8](NO3)2 dropcast onto an inert graphite surface. In both cases, a characteristic sequence of CO and benzene desorption steps is observed followed at higher excitation energy by H2 loss. This behavior is indicative of Pt-catalyzed C–H activation of phenyl groups during partial stripping of the ligand shell while the Pt17P8 cluster core is retained.
Robust and Regular Micronano Binary Texture on the Complex Curved Surface for Enhanced Reendothelialization and Antithrombotic Performance
Jing Zhang - ,
Wenyuan Yu - ,
Guoqiang Li - ,
Guiling Li - ,
Baolan Chen - ,
Luwen Wang *- ,
Yang Yu *- ,
Zhiyuan Liu *- , and
Donghai Li *
Blood-contacting medical devices can easily trigger immune responses, leading to thrombosis and hyperblastosis. Constructing microtexture that provides efficient antithrombotic and rapid reendothelialization performance on complex curved surfaces remains a pressing challenge. In this work, we present a robust and regular micronano binary texture on the titanium surface, characterized by exceptional mechanical strength and precisely controlled wettability to achieve excellent hemocompatibility. Systematic in vitro and in vivo investigations confirmed that the micronano binary texture with superhydrophilic modification effectively suppressed the adhesion and activation of plasma proteins and blood cells, thereby mitigating the subsequent coagulation cascade and thrombosis. Meanwhile, the modified surface significantly upregulated the gene expression involving cell–matrix adhesion, growth factor synthesis, and calcium-mediated cytoskeleton remodeling and then accelerated the formation of a healthy and stable endothelial cell layer. This enhancement of re-endothelialization was not observed with pure titanium and superhydrophobic surfaces. Hence, superhydrophilic micronano binary texture not only significantly inhibits thrombosis but also selectively enhances the integrity and viability of the endothelial cell layer, making it a promising strategy for improving the long-term anticoagulation performance of vascular implants.
Advances, Challenges, and Opportunities in Plasmonic Nanogap-Enhanced Raman Scattering with Nanoparticles
Gyeong-Hwan Kim - ,
Jiwoong Son - , and
Jwa-Min Nam *
Surface-enhanced Raman scattering has been widely used for molecular/material characterization and chemical and biological sensing and imaging applications. In particular, plasmonic nanogap-enhanced Raman scattering (NERS) is based on the highly localized electric field formed within the nanogap between closely spaced metallic surfaces to more strongly amplify Raman signals than the cases with molecules on metal surfaces. Nanoparticle-based NERS offers extraordinarily strong Raman signals and a plethora of opportunities in sensing, imaging and many different types of biomedical applications. Despite its potential, several challenges still remain for NERS to be widely useful in real-world applications. This Perspective introduces various plasmonic nanogap configurations with nanoparticles, discusses key advances and critical challenges while addressing possible misunderstandings in this field, and provides future directions for NERS to generate stronger, more uniform, and stable signals over a large number of structures for practical applications.
Induction of Antigen-Specific Tolerance in a Multiple Sclerosis Model without Broad Immunosuppression
Rebeca T. Stiepel - ,
Sean R. Simpson - ,
Nicole Rose Lukesh - ,
Denzel D. Middleton - ,
Dylan A. Hendy - ,
Luis Ontiveros-Padilla - ,
Stephen A. Ehrenzeller - ,
Md Jahirul Islam - ,
Erik S. Pena - ,
Michael A. Carlock - ,
Ted M. Ross - ,
Eric M. Bachelder - , and
Kristy M. Ainslie *
Multiple sclerosis (MS) is a severe autoimmune disorder that wreaks havoc on the central nervous system, leading to a spectrum of motor and cognitive impairments. There is no cure, and current treatment strategies rely on broad immunosuppression, leaving patients vulnerable to infections. To address this problem, our approach aims to induce antigen-specific tolerance, a much-needed shift in MS therapy. We have engineered a tolerogenic therapy consisting of spray-dried particles made of a degradable biopolymer, acetalated dextran, and loaded with an antigenic peptide and tolerizing drug, rapamycin (Rapa). After initial characterization and optimization, particles were tested in a myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis model of MS. Representing the earliest possible time of diagnosis, mice were treated at symptom onset in an early therapeutic model, where particles containing MOG and particles containing Rapa+MOG evoked significant reductions in clinical score. Particles were then applied to a highly clinically relevant late therapeutic model during peak disease, where MOG particles and Rapa+MOG particles each elicited a dramatic therapeutic effect, reversing hind limb paralysis and restoring fully functional limbs. To confirm the antigen specificity of our therapy, we immunized mice against the influenza antigen hemagglutinin (HA) and treated them with MOG particles or Rapa+MOG particles. The particles did not suppress antibody responses against HA. Our findings underscore the potential of this particle-based therapy to reverse autoimmunity in disease-relevant models without compromising immune competence, setting it apart from existing treatments.
Moisture-Electric Generators Working in Subzero Environments Based on Laser-Engraved Hygroscopic Hydrogel Arrays
Fei Yu - ,
Liying Wang - ,
Xijia Yang - ,
Yue Yang - ,
Xuesong Li *- ,
Yang Gao - ,
Yi Jiang - ,
Ke Jiang - ,
Wei Lü *- ,
Xiaojuan Sun *- , and
Dabing Li
Moisture-electric generators (MEGs) generate power by adsorbing water from the air. However, their performance at low temperatures is hindered due to icing. In the present work, MEG arrays are developed by laser engraving techniques and a modulated low-temperature hydrogel as the absorbent material. LTH effectively captures moisture and maintains ion dissociation and migration even at subzero temperatures. Based on the double electric layer pseudocapacitance model, the oscillating circuit theory is introduced to explain the effects of moisture absorption, evaporation, and ion migration on the output current of the MEG, and the circuit calculations are matched with the experimental results. Molecular dynamics simulations indicate that LTH’s low-temperature stability results from preferential hydrogen bonding between glycerol molecules and H2O, which disrupts H2O–H2O hydrogen bonds and slows water crystallization. A single MEG unit (0.25 cm2) can produce up to ∼0.8 V and ∼21.2 μW/cm2 at room temperature, and at −35 °C with 16% RH, it generates ∼0.58 V and ∼14.35 μA. MEG realizes the following applications: MEG successfully drives electronic devices in snow; arrays of 16 MEGs can power portable electronics, and 384 MEGs can achieve up to 210 V; MEG absorbs moisture in water and drives LEDs by blowing up; MEG has a flexible wearable nature; MEG is used for respiratory monitoring and photoelectric sensors.
Parameter Pool-Assisted Centrifugation Sorter for Multiscale Higher-Order DNA Nanomaterials
Lilin Ouyang - ,
Junke Wang - ,
Bing Liu - ,
Mo Xie - ,
Lianhui Wang - ,
Chunhai Fan - , and
Jie Chao *
Higher-order DNA nanomaterials have emerged as programmable tools for probing biological processes, constructing metamaterials, and manipulating mechanically active nanodevices with the multifunctionality and high-performance attributes. However, their utility is limited by intricate mixtures formed during hierarchical multistage assembly, as standard techniques like gel electrophoresis lack the resolution and applicability needed for precise characterization and enrichment. Thus, it is urgent to develop a sorter that provides high separation resolution, broad scope, and bioactive functionality. Here, we present a versatile and scalable sorting pipeline based on a centrifugation parameter pool capable of distinguishing DNA nanomaterials across multiple scales. By tuning parameters, we achieved high-throughput classification of nanostructures, spanning from DNA tile-based constructs to DNA origami-based assemblies (∼50 MDa, 75,000 bp), surpassing conventional methods. Furthermore, we optimized the separation resolution to less than 78 kDa (∼120 bp) at a large scale by sorting DNA tetrahedron structures using this systematic parameter pool-assisted centrifugation strategy. This sorter maintains the integrity and functionality of bioactive materials, facilitating a seamless transition from assembly to application, allowing for integration with proteins and other components to achieve the fabrication of complex functional materials and programmable molecular machines across interdisciplinary fields within the nanotechnology community.
Solid-State Nanopore Real-Time Assay for Monitoring Cas9 Endonuclease Reactivity
Chalmers C. C. Chau *- ,
Nicole E. Weckman - ,
Emma E. Thomson - , and
Paolo Actis
This publication is Open Access under the license indicated. Learn More
The field of nanopore sensing is now moving beyond nucleic acid sequencing. An exciting avenue is the use of nanopore platforms for the monitoring of biochemical reactions. Biological nanopores have been used for this application, but solid-state nanopore approaches have lagged. This is due to the necessity of using higher salt conditions (e.g., 4 M LiCl) to improve the signal-to-noise ratio which completely abolish the activities of many biochemical reactions. We pioneered a polymer electrolyte solid-state nanopore approach that maintains a high signal-to-noise ratio even at a physiologically relevant salt concentration. Here, we report the monitoring of the restriction enzyme SwaI and CRISPR-Cas9 endonuclease activities under physiological salt conditions and in real time. We investigated the dsDNA cleavage activity of these enzymes in a range of digestion buffers and elucidated the off-target activity of CRISPR-Cas9 ribonucleoprotein endonuclease in the presence of single base pair mismatches. This approach enables the application of solid-state nanopores for the dynamic monitoring of biochemical reactions under physiological salt conditions.
Enormous Out-of-Plane Charge Rectification and Conductance through Two-Dimensional Monolayers
Anthony Cabanillas - ,
Simran Shahi - ,
Maomao Liu - ,
Hemendra Nath Jaiswal - ,
Sichen Wei - ,
Yu Fu - ,
Anindita Chakravarty - ,
Asma Ahmed - ,
Xiaochi Liu - ,
Jian Sun - ,
Cheng Yang - ,
Won Jong Yoo - ,
Theresia Knobloch - ,
Vasili Perebeinos - ,
Antonio Di Bartolomeo - ,
Tibor Grasser *- ,
Fei Yao *- , and
Huamin Li *
Heterogeneous integration of emerging two-dimensional (2D) materials with mature three-dimensional (3D) silicon-based semiconductor technology presents a promising approach for the future development of energy-efficient, function-rich nanoelectronic devices. In this study, we designed a mixed-dimensional junction structure in which a 2D monolayer (e.g., graphene, MoS2, and h-BN) is sandwiched between a metal (e.g., Ti, Au, and Pd) and a 3D semiconductor (e.g., p-Si) to investigate charge transport properties exclusively in an out-of-plane (OoP) direction. The role of 2D monolayers as either an OoP metal-to-semiconductor charge injection barrier or an OoP semiconductor-to-metal charge collection barrier was comparatively evaluated. Compared to monolayer graphene, monolayer MoS2 and h-BN effectively modulate OoP metal-to-semiconductor charge injection through a barrier tunneling effect. Their effective OoP resistance and resistivity were extracted using a resistors-in-series model. Intriguingly, when functioning as a semiconductor-to-metal charge collection barrier, all 2D monolayers become electronically “transparent” (close to zero resistance) when a high OoP voltage (greater than the built-in voltage) is applied. As a mixed-dimensional integrated diode, the Ti/MoS2/p-Si and Au/MoS2/p-Si configurations exhibit both high OoP rectification ratios (5.4 × 104) and conductance (1.3 × 105 S/m2). Our work demonstrates the tunable OoP charge transport characteristics at a 2D/3D interface, suggesting the opportunity for 2D/3D heterogeneous integration, even with sub-1 nm thick 2D monolayers, to enhance modern Si-based electronic devices.
The Road to Commercializing Optical Metasurfaces: Current Challenges and Future Directions
Younghwan Yang - ,
Eunji Lee - ,
Yujin Park - ,
Junhwa Seong - ,
Hongyoon Kim - ,
Hyunjung Kang - ,
Dohyun Kang - ,
Doohyuk Han - , and
Junsuk Rho *
Optical metasurfaces, components composed of artificial nanostructures, are recognized for pushing boundaries of wavefront manipulation while maintaining a lightweight, compact design that surpasses conventional optics. Such advantages align with the current trends in optical systems, which demand compact communication devices and immersive holographic projectors, driving significant investment from the industry. Although interest in commercialization of optical metasurfaces has steadily grown since the initial breakthrough with diffraction-limited focusing, their practical applications have remained limited by challenges such as, massive-production yield, absence of standardized evaluation methods, and constrained design methodology. Here, this Perspective addresses the challenges in commercialization of optical metasurfaces, particularly focused on mass production, fabrication tolerance, performance evaluation, and integration into commercial systems. Additionally, we select the fields where metasurfaces may soon play significant roles and provide a perspective on their potentials. By addressing the challenges and exploring the solutions, this Perspective aims to foster discussions that will accelerate the utilization of optical metasurfaces and further build near-future metaphotonics platforms.
Revealing the Limitations of the Thermocapacitive Cycle
Yining Lao - ,
Pei Tang - ,
Jinquan Zeng - ,
Shan Xu - ,
Jian Zhu - ,
Qingyun Dou - ,
Xiaohua Xiao - , and
Xingbin Yan *
While thermoelectric conversion by a thermocapacitive cycle has been considered a promising green technology for low-grade heat recovery, our study finds that its practical feasibility is overestimated. During thermal charging, the coexistence and dynamic competition between thermal-induced voltage rise and self-discharge lead to the limitations of the thermocapacitive cycle. Therefore, the operational conditions in the charge-heat-discharge steps seriously restrict the thermal charging performance. The calculation of energy efficiency further confirms the economic infeasibility of the thermocapacitive cycle. This study provides insights into comprehending the principle and process of thermoelectric conversion by thermocapacitive cycle and will guide the rational development of capacitive heat-to-current converters.
A Thermally Robust Biopolymeric Separator Conveys K+ Transport and Interfacial Chemistry for Longevous Potassium Metal Batteries
Yuyuan Wang - ,
Liang Xu - ,
Xiaopeng Chen - ,
Ziang Chen - ,
Xinhua Li - ,
Wenyi Guo - ,
Tao Cheng *- ,
Yuyang Yi *- , and
Jingyu Sun *
Potassium metal batteries (KMBs) hold promise for stationary energy storage with certain cost and resource merits. Nevertheless, their practicability is greatly handicapped by dendrite-related anodes, and the target design of specialized separators to boost anode safety is in its nascent stage. Here, we develop a thermally robust biopolymeric separator customized via a solvent-exchange and amino-siloxane decoration strategy to render durable and safe KMBs. Through experimental investigation and theoretical computation, we reveal that the optimized porosity and surface functionalization could manage ion transport and interfacial chemistry, thereby enabling efficient K+ diffusion and a favorable solid electrolyte interphase to achieve prolonged cycling stability (over 3000 h). The thus-assembled full cell retains 80% of its initial capacity after 400 cycles at 0.5 A g–1. The heat-proof property of the designed separator is further demonstrated. Our biopolymeric separator, affording multifunctional features, provides an appealing solution to circumvent instability and safety issues associated with potassium metal batteries.
Deciphering the Sulfur-Involved Bonding Interactions in Sulfurized Polyacrylonitrile: The Formation Thermodynamics and the Roles in Electrochemical Characteristics
Jingyi Xie - ,
Junxiong Chen - ,
Lingling Guo - ,
Yande Li - ,
Yibo Wang - ,
Shun Zheng - ,
Nian Zhang - ,
Jianwei Meng - ,
Kaiyu Zhang - ,
Qinghao Li *- ,
Tsu-Chien Weng *- ,
Pengfei Yu *- , and
Xiaosong Liu *
Sulfurized polyacrylonitrile (SPAN) exhibits a very high cycle stability by overcoming the shuttle effect of conventional Li–S batteries. However, there are still controversies in SPAN about the bonding types of sulfur with the matrix, their critical synthesis temperature regions, and their roles in the electrochemical lithium storage reaction, seriously hindering the economical synthesis of SPAN, the optimization of performances, and the exploration of other SPAN-like alternatives. The key to solving the above problems lies in accurate measurements of the thermodynamic evolution of bonding interactions in the synthesis process as well as in the electrochemical process. In this study, soft and tender X-ray absorption spectroscopy (XAS) is utilized to achieve a fine resolution of specific bonding interactions through the selective excitation of C, N, and S. Sulfur-involved bonding interactions have been elucidated, including the bonding type, critical temperature region, linking site, and their interplays. Furthermore, their contributions to lithium storage and their regulations on electrochemical performances are discussed. This study demonstrates the resolving capability of XAS for organic electrode materials and provides insights for further analyzing the cyclability of SPAN and rationally designing alternatives from the perspective of bonding interactions.
Capillary-Assisted Confinement Assembly for Advanced Sensor Fabrication: From Superwetting Interfaces to Capillary Bridge Patterning
Zhihao Zhao - ,
Weijie Wang - ,
Gongmo Xiang - ,
Lei Jiang - , and
Xiangyu Jiang *
Precise patterning of sensing materials, particularly the long-range-ordered assembly of micro/nanostructures, is pivotal for improving sensor performance, facilitating miniaturization, and enabling seamless integration. This paper examines the importance of interfacial confined assembly in sensor patterning, including gas–liquid and liquid–liquid confined assembly, wettability-assisted or microstructure-assisted solid–liquid interfacial confined assembly, and tip-induced confined assembly. The application of capillary bridge confined assembly technology in chemical sensors, flexible electronics, and optoelectronics is highlighted. The advantages of capillary bridge confined assembly technology include the ability to achieve high-resolution patterning, scalability, and material arrangement in long-range order. It is, therefore, an ideal processing platform for next-generation sensors. Finally, the broad prospects of this technology in the miniaturization and integration of high-performance multifunctional sensors are discussed.
January 14, 2025
Liquid Active Surface Growth: Explaining the Symmetry Breaking in Liquid Nanoparticles
Huai Lin - ,
Huiying Guo - ,
Xuejun Cheng - ,
An Su - ,
Liping Huang - ,
Qingwu Yao - ,
Xiaohuo Shi - ,
Ruoxu Wang *- , and
Hongyu Chen *
In our previous studies of metal nanoparticle growth, we have come to realize that the dynamic interplay between ligand passivation and metal deposition, as opposed to static facet control, is responsible for focused growth at a few active sites. In this work, we show that the same underlying principle could be applied to a very different system and explain the abnormal growth modes of liquid nanoparticles. In such a liquid active surface growth (LASG), the interplay between droplet expansion and simultaneous silica shell encapsulation gives rise to an active site of growth, which eventually becomes the long necks of nanobottles. For this synthetic control, the imbalance of the said interplay is the critical factor, as demonstrated by carefully designed control experiments. Thus, LASG provides a coherent mechanism that encompasses a wide range of liquid-derived nanostructures, including hollow nanospheres, asymmetric teardrops, and hollow nanobottles with an opening. By adapting nanosynthesis techniques from the solid to liquid realm, we believe that LASG would provide deeper insights and more sophisticated synthetic controls.
Shape Anisotropy-Dependent Leaking in Magnetic Neurons for Bio-Mimetic Neuromorphic Computing
Thomas Leonard - ,
Nicholas Zogbi - ,
Samuel Liu - ,
William S. Rogers - ,
Christopher H. Bennett - , and
Jean Anne C. Incorvia *
Spiking neural networks seek to emulate biological computation through interconnected artificial neuron and synapse devices. Spintronic neurons can leverage magnetization physics to mimic biological neuron functions, such as integration tied to magnetic domain wall (DW) propagation in a patterned nanotrack and firing tied to the resistance change of a magnetic tunnel junction (MTJ), captured in the domain wall-magnetic tunnel junction (DW-MTJ) device. Leaking, relaxation of a neuron when it is not under stimulation, is also predicted to be implemented based on DW drift as a DW relaxes to a low energy position, but it has not been well explored or demonstrated in device prototypes. Here, we study DW-MTJ artificial neurons capable of leaky integrate-and-fire (LIF) behavior and demonstrate geometry-dependent leaking dynamics that results in repeatable, tunable LIF operation. Studying the behavior of five different device designs, we show tuning the geometry, stimulating fields and currents, and location of electrical contacts results in a wide range of neuron behavior. Additionally, implementation of an asymmetric notch allows for nonlinear pinning which increased expressivity without sacrificing leaking. The measured behavior is implemented in a simulated spiking neural network that outperforms a 1D model of continuous DW motion and approaches the performance of an ideal LIF activation function. The results show that the analog LIF capability of DW-MTJ neurons combines many desirable neuron functions into a single device, which can result in varied forms of multifunctional neuromorphic computing.
Oxygen-Passivated Sulfur Vacancies in Monolayer MoS2 for Enhanced Piezoelectricity
Ajay Kumar Verma - ,
Md. Ataur Rahman - ,
Pargam Vashishtha - ,
Xiangyang Guo - ,
Manoj Sehrawat - ,
Rahul Mitra - ,
Sindhu P. Giridhar - ,
Moaz Waqar - ,
Ankit Bhoriya - ,
Billy J. Murdoch - ,
Chenglong Xu - ,
Ali Zavabeti - ,
Wei Qian Song - ,
Yongxiang Li - ,
Sanjay R. Dhakate - ,
Bhasker Gahtori - ,
Taimur Ahmed - ,
Irfan H. Abidi *- , and
Sumeet Walia *
Modern-day applications demand onboard electricity generation that can be achieved using piezoelectric phenomena. Reducing the dimensionality of materials is a pathway to enhancing the piezoelectric properties. Transition-metal dichalcogenides have been shown to exhibit high piezoelectricity. Monolayer MoS2 possesses strong piezoelectricity that is otherwise negligible in its bulk form. The presence of sulfur vacancy defects in two-dimensional MoS2 can starkly reduce piezoelectric output due to enhanced charge screening. Oxygen passivation offers thermodynamically favorable and superior vacancy passivation. Here, we demonstrate an in situ oxygen passivation of sulfur vacancies achieved by performing chemical vapor deposition in atmospheric pressure conditions, resulting in a dramatically enhanced piezoelectric output. We achieved an out-of-plane effective piezoelectric coefficient d33eff 0.54 pm/V for the MoS2 monolayer with sulfur vacancies (SV-MoS2) and 0.94 pm/V where sulfur vacancies are passivated by oxygen (OP-MoS2). The piezoelectric device (PED) based on OP-MoS2 exhibits 26% higher output voltage than SV-MoS2 with the maximum peak-to-peak value of 0.95 V. Additionally, we show that the OP-MoS2-based PED can charge a 330 nF capacitor 30% faster than the SV-MoS2 PED for up to 50 mV in 0.5 s by repetitive finger tapping. The evolution of piezoelectricity in MoS2 with sulfur vacancy defect manipulation promises an avenue for scalable defect engineering for next-generation applications in miniaturized self-powered electronics and sensors across computing, healthcare, and size-, weight-, and power-constrained environments.
Symmetric Diblock Copolymers Form Versatile and Switchable Ultrasmall Nanoparticles
Artem Petrov *- ,
Guillermo A. Hernández-Mendoza - , and
Alfredo Alexander-Katz *
Block copolymers (BCPs) can form nanoparticles having different morphologies that can be used as photonic nanocrystals and are a platform for drug delivery, sensors, and catalysis. In particular, BCP nanoparticles having disk-like shape have been recently discovered. Such nanodisks can be used as the next-generation antitumor drug delivery carriers; however, the applicability of the existing nanodisks is limited due to their poor or unknown ability to respond to external stimuli. In this work, we showed that the simplest symmetric diblock copolymers in equilibrium can form nanodisks that can be reversibly switched into a multitude of various nanoparticles potentially applicable in nanophotonics, biomedicine, and hierarchical self-assembly. These structures include patchy and onion-like nanoparticles, striped ellipsoids, mixed morphology nanocolloids, and spherical micelles. The transitions between nanodisks and the aforementioned nanoparticles are sharp, direct, and can be achieved by tuning the block–block and polymer–solvent incompatibility. We demonstrated that this versatility of nanoparticle morphologies can be achieved upon reducing the nanoparticle size to approximately two lamellar periods of the BCP. Upon aggregation of such small nanocolloids, a larger assembly can be formed. In turn, these bigger particles could form many other structures including a chain-like supramolecular aggregate of nanodisks and a multilayered disk-like nanoparticle. We obtained our results by performing self-consistent field theory calculations according to an algorithm designed to produce equilibrium nanoparticle morphology. This work demonstrates that nanodisks prepared from the simplest type of BCPs are extremely tunable; therefore, symmetric diblock copolymers can become a platform for producing the next-generation stimuli-responsive nanoparticles.
Direct Electrical Access to the Spin Manifolds of Individual Lanthanide Atoms
Gregory Czap - ,
Kyungju Noh - ,
Jairo Velasco Jr.- ,
Roger M. Macfarlane - ,
Harald Brune *- , and
Christopher P. Lutz *
This publication is Open Access under the license indicated. Learn More
Lanthanide atoms show long magnetic lifetimes because of their strongly localized 4f electrons, but electrical control of their spins has been difficult because of their closed valence shell configurations. We achieved electron spin resonance of individual lanthanide atoms using a scanning tunneling microscope to probe the atoms bound to a protective insulating film. The atoms on this surface formed a singly charged cation state having an unpaired 6s electron, enabling tunnel current to access their 4f electrons. Europium spectra display a rich array of transitions among the 54 combined electron and nuclear spin states. In contrast, samarium’s ground state is a Kramers doublet with a very large g-factor of 5. These results demonstrate that all-electronic sensing and control of individual lanthanide spins is possible for quantum devices and spin-based electronics by using their rarely observed monovalent cation state.
Olfactory-Inspired Separation-Sensing Nanochannel-Based Electronics for Wireless Sweat Monitoring
Yuge Wu - ,
Qi Wang - ,
Xin Li - ,
Ke Li - ,
Dehua Huang - ,
Kehan Zou - ,
Zhehua Zhang - ,
Yongchao Qian - ,
Congcong Zhu *- ,
Xiang-Yu Kong - , and
Liping Wen *
Human sweat has the potential to be sufficiently utilized for noninvasive monitoring. Given the complexity of sweat secretion, the sensitivity and selectivity of sweat monitoring should be further improved. Here, we developed an olfactory-inspired separation-sensing nanochannel-based electronic for sensitive and selective sweat monitoring, which was simultaneously endowed with interferent separation and target detection performances. The special separation-sensing strategy imparts functional composite membranes with a high sensitivity of 113 mV dec–1 for potassium detection. The excellent mechanical properties and conformability of the Kevlar aramid nanofiber layer bring well-wearing performances to realize continuous wireless sweat monitoring. The recognition between functional molecules and target ions is proved at the molecular level in detail in the article. The replacement of functional molecules proves the universality of the strategy for performance enhancement in intricate biofluid analysis systems.
Creation of Piezoelectricity in Quadruple Perovskite Oxides by Harnessing Cation Defects and Their Application in Piezo-Photocatalysis
Kai Wang - ,
Xiangyu Guo *- ,
Chen Han - ,
Lihong Liu *- ,
Zhiliang Wang - ,
Lars Thomsen - ,
Peng Chen - ,
Zongping Shao - ,
Xudong Wang *- ,
Fang Xie - ,
Gang Liu - ,
Lianzhou Wang *- , and
Shaomin Liu *
Quadruple perovskite oxides have received extensive attention in electronics and catalysis, owing to their cation-ordering structure and intriguing physical properties. However, their repertoires still remain limited. In particular, piezoelectricity from quadruple perovskites has been rarely reported due to the frustrated symmetry-breaking transition in A-site-ordered perovskite structures, disabling their piezoelectric applications. Herein, we report a feasible strategy to achieve piezoelectricity in CaCu3Ti4O12 (CCTO) quadruple perovskite via cation defect engineering, specifically through a thermal-driven selective cation exsolution strategy to introduce Cu vacancies. The introduction of Cu point defects in CCTO locally destabilizes the constrained tilted TiO6 octahedra framework, relaxing the octahedral tilting and inducing structural heterogeneity which, in turn, disrupts the high symmetry of the pristine cubic phase. As a result, the defective CCTO with localized asymmetry exhibits intense polarization and a robust piezoelectricity of 7 pC N–1. The created piezoelectricity is further validated by its application as a piezo-photocatalyst, enabling efficient charge separation and transfer with a 2.5-times increment in the lifetime of photoexcitations. This enhancement leads to a 3.86- and 31-fold increase in the production of hydrogen peroxide and reactive oxygen species compared with individual piezocatalysis and photocatalysis, respectively. This study establishes a pathway to engineer piezoelectricity in quadruple perovskites, potentially unlocking a wide range of applications in modern microelectronics beyond the demonstrated piezo-photocatalysis.
Revealing Multistep Phase Separation in Metal Alloy Nanoparticles with In Situ Transmission Electron Microscopy
Yingying Jiang - ,
Zicong Marvin Wong - ,
Hongwei Yan - ,
Teck Leong Tan - , and
Utkur Mirsaidov *
Phase separation plays a crucial role in many natural and industrial processes, such as the formation of clouds and minerals and the distillation of crude oil. In metals and alloys, phase separation is an important approach often utilized to improve their mechanical strength for use in construction, automobile, and aerospace manufacturing. Despite its importance in many processes, the atomic details of phase separation are largely unknown. In particular, it is unclear how a different crystal phase emerges from the parent alloy. Here, using real-time in situ transmission electron microscopy, we describe the stages of the phase separation in face-centered cubic (fcc) AuRu alloy nanoparticles, resulting in a Ru phase with a hexagonal close-packed (hcp) crystal structure. Our observation reveals that the hcp Ru phase forms in two steps: the spinodal decomposition of the alloy produces metastable fcc Ru clusters, and as they grow larger, these clusters transform into hcp Ru domains. Our calculations indicate that the primary reason for the fcc-to-hcp transformation is the size-dependent competition between the interfacial and bulk energies of Ru domains. These insights into elusive, transient steps in the phase separation of alloys can aid in engineering nanomaterials with unconventional phases.
Inhalable Metal–Organic Frameworks: A Promising Delivery Platform for Pulmonary Diseases Treatment
Qifan Yu - ,
Qiang Zhang - ,
Zhiqiang Wu - , and
Yang Yang *
Inhalation delivery, offering a direct pathway for administering drugs to the lungs in the form of dry powders or aerosols, stands out as an optimal approach for the localized treatment of pulmonary diseases. However, the intricate anatomical architecture of the lung often poses challenges in maintaining effective drug concentrations within the lungs over extended periods. This highlights the pressing need to develop rational inhalable drug delivery systems that can improve treatment outcomes for respiratory diseases. Metal–organic frameworks (MOFs) assembled from inorganic metal ions and organic ligands, characterized by customizable porous architecture and chemical composition, modifiable porosity, vast surface area, straightforward surface modification, and adjustable biocompatibility, have garnered extensive attention in the biomedical sphere. The introduction of MOFs into inhalation therapy represents a promising avenue to navigate past the hurdles associated with traditional inhalation methods. Therefore, this review summarizes the characteristics of inhalation delivery together with the latest advances, challenges, and opportunities in utilizing inhalable MOFs for treating lung diseases and discusses prospects in this field alongside the potential pathways for translating this strategy into clinic.
Heteroconfinement in Single CdTe Nanoplatelets
Tasnim Ahmed - ,
Xuanheng Tan - ,
Barry Y. Li - ,
Elijah Cook - ,
Jillian Williams - ,
Sophia M. Tiano - ,
Belle Coffey - ,
Stephanie M. Tenney - ,
Dugan Hayes - , and
Justin R. Caram *
Dimension-engineered synthesis of atomically thin II–VI nanoplatelets (NPLs) remains an open challenge. While CdSe NPLs have been made with confinement ranging from 2 to 11 monolayers (ML), CdTe NPLs have been significantly more challenging to synthesize and separate. Here we provide detailed mechanistic insight into the layer-by-layer growth kinetics of the CdTe NPLs. Combining ensemble and single-particle spectroscopic and microscopic tools, our work suggests that beyond 2 ML CdTe NPLs, higher ML structures initially appear as heteroconfined materials with colocalized multilayer structures. In particular, we observe strongly colocalized 3 and 4 ML emissions, accompanied by a broad trap emission. Accompanying transient absorption, single-particle optical, and atomic force microscopy analyses suggest islands of different MLs on the same NPL. To explain the nonstandard nucleation and growth of these heteroconfined structures, we simulated the growth conditions of NPLs and quantified how the monomer binding energy modifies the kinetics and permits single NPLs with multi-ML structures. Our findings suggest that the lower bond energy associated with CdTe relative to CdSe limits higher ML syntheses and explains the observed differences between CdTe and CdSe growth.
January 13, 2025
Tumor Vaccine Exploiting Membranes with Influenza Virus-Induced Immunogenic Cell Death to Decorate Polylactic Coglycolic Acid Nanoparticles
Ying Yang - ,
Yongmao Hu - ,
Ying Yang - ,
Qingwen Liu - ,
Peng Zheng - ,
Zhongqian Yang - ,
Biao Duan - ,
Jinrong He - ,
Weiran Li - ,
Duo Li - ,
Xiao Zheng - ,
Mengzhen Wang - ,
Yuting Fu - ,
Qiong Long *- , and
Yanbing Ma *
Immunogenic cell death (ICD) of tumor cells, which is characterized by releasing immunostimulatory “find me” and “eat me” signals, expressing proinflammatory cytokines and providing personalized and broad-spectrum tumor antigens draws increasing attention in developing a tumor vaccine. In this study, we aimed to investigate whether the influenza virus (IAV) is efficient enough to induce ICD in tumor cells and an extra modification of IAV components such as hemeagglutinin (HA) will be helpful for the ICD-induced cells to elicit robust antitumor effects; in addition, to evaluate whether the membrane-engineering polylactic coglycolic acid nanoparticles (PLGA NPs) simulating ICD immune stimulation mechanisms hold the potential to be a promising vaccine candidate, a mouse melanoma cell line (B16–F10 cell) was infected with IAV rescued by the reverse genetic system, and the prepared cells and membrane-modified PLGA NPs were used separately to immunize the melanoma-bearing mice. IAV-infected tumor cells exhibit dying status, releasing high mobility group box-1 (HMGB1) and adenosine triphosphate (ATP), and exposing calreticulin (CRT), IAV hemeagglutinin (HA), and tumor antigens like tyrosinase-related protein 2 (TRP2). IAV-induced ICD cells enhance biomass-derived carbon (BMDCs) migration, antigen uptake, cross-presentation, and maturation in vitro. Furthermore, immunization with IAV-induced ICD cells effectively suppressed tumor growth in melanoma-bearing mice. The isolated cell membrane inherited the immunological characteristics from the ICD cells and elicited robust antitumor immune responses through decorating PLGA NPs loading with a tumor-specific helper T-cell peptide and supplemented with ATP in a hydrogel system. This study indicated a promising strategy for developing cell-based and personalized tumor vaccines through fully taking advantage of the immune stimulation mechanisms of ICD occurrence in tumor cells, IAV modification, and nanoscale delivery.
Transforming Detrimental Crystalline Zinc Hydroxide Sulfate to Homogeneous Fluorinated Amorphous Solid–Electrolyte Interphase on Zinc Anode
Siyu Tian - ,
Taesoon Hwang - ,
Zhuoxun Zhang - ,
Shiwen Wu - ,
Amirarsalan Mashhadian - ,
Renzheng Zhang - ,
Tye Milazzo - ,
Tengfei Luo - ,
Ruda Jian - ,
Tianyi Li - ,
Kyeongjae Cho *- , and
Guoping Xiong *
The formation of non-ion conducting byproducts on zinc anode is notoriously detrimental to aqueous zinc-ion batteries (AZIBs). Herein, we successfully transform a representative detrimental byproduct, crystalline zinc hydroxide sulfate (ZHS) to fast-ion conducting solid-electrolyte interphase (SEI) via amorphization and fluorination induced by suspending CaF2 nanoparticles in dilute sulfate electrolytes. Distinct from widely reported nonhomogeneous organic–inorganic hybrid SEIs that exhibit structural and chemical instability, the designed single-phase SEI is homogeneous, mechanically robust, and chemically stable. These characteristics of the SEI facilitate the prevention of zinc dendrite growth and reduction of capacity loss during long-term cycling. Importantly, AZIB full cells based on this SEI-forming electrolyte exhibit exceptional stability over 20,000 cycles at 3 A/g with a charging voltage of 2.2 V without short circuits and electrolyte dry-out. This work suggests avenues for designing SEIs on a metal anode and provides insights into associated SEI chemistry.
Perovskite Nanocrystal Self-Assemblies in 3D Hollow Templates
Etsuki Kobiyama - ,
Darius Urbonas - ,
Benjamin Aymoz - ,
Maryna I. Bodnarchuk *- ,
Gabriele Rainò - ,
Antonis Olziersky - ,
Daniele Caimi - ,
Marilyne Sousa - ,
Rainer F. Mahrt - ,
Maksym V. Kovalenko *- , and
Thilo Stöferle *
This publication is Open Access under the license indicated. Learn More
Highly ordered nanocrystal (NC) assemblies, namely, superlattices (SLs), have been investigated as materials for optical and optoelectronic devices due to their unique properties based on interactions among neighboring NCs. In particular, lead halide perovskite NC SLs have attracted significant attention owing to their extraordinary optical characteristics of individual NCs and collective emission processes like superfluorescence (SF). So far, the primary method for preparing perovskite NC SLs has been the drying-mediated self-assembly method, in which the colloidal NCs spontaneously assemble into SLs during solvent evaporation. However, this method lacks controllability because NCs form random-sized SLs at random positions on the substrate, rendering NC assemblies in conjunction with device structures, such as photonic waveguides or microcavities, challenging. Here, we demonstrate template-assisted self-assembly to deterministically place perovskite NC SLs and control their geometrical properties. A solution of CsPbBr3 NCs is drop-casted on a substrate with lithographically defined hollow structures. After solvent evaporation and removal of excess NCs from the substrate surface, NCs remain only in the templates, thereby defining the position and size of these NC assemblies. We performed photoluminescence (PL) measurements on these NC assemblies and observed signatures of SF, similar to those in spontaneously assembled SLs. Our findings are crucial for optical devices that harness embedded perovskite NC assemblies and enable fundamental studies on how these collective effects can be tailored through the SL geometry.
Combating Antibiotic-Resistant Bacterial Infection Using Coassembled Dimeric Antimicrobial Peptide-Based Nanofibers
Guoyu Li - ,
Haoran Deng - ,
Wanying Xu - ,
Wenwen Chen - ,
Zhenheng Lai - ,
Yongjie Zhu - ,
Licong Zhang - ,
Changxuan Shao *- , and
Anshan Shan *
The emergence of multidrug-resistant (MDR) pathogens, coupled with the limited effectiveness of existing antibiotics in eradicating biofilms, presents a significant threat to global health care. This critical situation underscores the urgent need for the discovery and development of antimicrobial agents. Recently, peptide-derived antimicrobial nanomaterials have shown promise in combating such infections. Amino acid noncovalent forces, notably π–π stacking and electrostatic interactions, remain underutilized for guiding the coassembly of peptides into bacteriostatic nanomaterials. Thus, we constructed a dimeric nanopeptide system using the disulfide bonds of cysteine. The self-assembly of dimeric peptides into nanofibers was realized by the interaction of π–π aromatic amino acids (Trp, Phe, and Pyr) and the electrostatic attraction between oppositely charged amino acids (Asp and Arg). The optimal dimeric peptide 2D2W exhibits potent antibacterial activity against resistant bacteria and is nontoxic. Mechanistically, 2D2W penetrated the outer membrane after electrostatic adsorption, resulting in plasma membrane depolarization, homeostatic disruption, and ultimately bacterial death. In a mouse model of peritonitis, 2D2W demonstrated efficacy in the in vivo treatment of bacterial infections. In conclusion, the design of dimeric nanopeptides co-driven by intermolecular forces provides a promising avenue for the development of high-performance antimicrobial nanomaterials. These advances may also facilitate the application and advancement of peptide-based bacteriostatic agents in clinical practice.
Robotic Microcapsule Assemblies with Adaptive Mobility for Targeted Treatment of Rugged Biological Microenvironments
Hong Huy Tran - ,
Zhenting Xiang - ,
Min Jun Oh - ,
Yuan Liu - ,
Zhi Ren - ,
Chider Chen - ,
Nadasinee Jaruchotiratanasakul - ,
James M. Kikkawa - ,
Daeyeon Lee *- ,
Hyun Koo *- , and
Edward Steager *
This publication is Open Access under the license indicated. Learn More
Microrobots are poised to transform biomedicine by enabling precise, noninvasive procedures. However, current magnetic microrobots, composed of solid monolithic particles, present fundamental challenges in engineering intersubunit interactions, limiting their collective effectiveness in navigating irregular biological terrains and confined spaces. To address this, we design hierarchically assembled microrobots with multiaxis mobility and collective adaptability by engineering the potential magnetic interaction energy between subunits to create stable, self-reconfigurable structures capable of carrying and protecting cargo internally. Using double emulsion templates and magnetic control techniques, we confine 10 nm iron oxide and 15 nm silica nanoparticles within the shell of 100 μm microcapsules that form multiunit robotic collectives. Unexpectedly, we find that asymmetric localization of iron oxide nanoparticles in the microcapsules enhances the intercapsule potential energy, creating stable connections under rotating magnetic fields without altering the magnetic susceptibility. These robotic microcapsule collectives exhibit emergent behaviors, self-reconfiguring into kinematic chain-like structures to traverse complex obstacles, arched confinements, and adhesive, rugged biological tissues that typically impede microscale systems. By harnessing these functions, we demonstrate targeted antifungal delivery using a localized biofilm model on mucosal tissues, showing effective killing ofCandida without binding or causing physical damage to host cells. Our findings show how hierarchical assembly can produce cargo-carrying microrobots with collective, self-adaptive mobility for traversing complex biological environments, advancing targeted delivery for biomedical applications.
Mitigating the Efficiency Deficit in Single-Crystal Perovskite Solar Cells by Precise Control of the Growth Processes
Tongpeng Zhao - ,
Ruiqin He - ,
Tanghao Liu *- ,
Yanhao Li - ,
De Yu - ,
Yuxin Gao - ,
Geyang Qu - ,
Ning Li - ,
Chunmei Wang - ,
Huang Huang - ,
Jiong Zhou - ,
Sai Bai - ,
Shumin Xiao - ,
Zhaolai Chen - ,
Yimu Chen *- , and
Qinghai Song *
The power conversion efficiencies (PCEs) of polycrystalline perovskite solar cells (PC–PSCs) have now reached a plateau after a decade of rapid development, leaving a distinct gap from their Shockley-Queisser limit. To continuously mitigate the PCE deficit, nonradiative carrier losses resulting from defects should be further optimized. Single-crystal perovskites are considered an ideal platform to study the efficiency limit of perovskite solar cells due to their intrinsically low defect density, as demonstrated in bulk single crystals. However, current single-crystal perovskite solar cells (SC-PSCs) based on single-crystal thin film (SCTF) suffer from severe nonradiative carrier losses at the interface and in the bulk simultaneously due to the immature SCTF growth techniques. In this study, we show that the SC-PSCs can outperform state-of-the-art PC–PSCs, with MAPbI3 as an example, by suppressing carrier losses at the interface and in the bulk in device-compatible SCTFs through precisely controlling their growth.
Rapid Preparation of Collagen/Red Blood Cell Membrane Tubes for Stenosis-Free Vascular Regeneration
Chunliang Zhang - ,
Chunyuan Wang - ,
Ruitao Cha *- ,
Qinghua Meng - ,
Zhan Hu - ,
Yang Sun - ,
Zulan Li - ,
Min Xiao *- ,
Yan Zhang *- , and
Xingyu Jiang *
Extracellular matrix (ECM)-based small-diameter vascular grafts (SDVGs, inner diameter (ID) < 6 mm) hold great promise for clinical applications. However, existing ECM-based SDVGs suffer from limited donor availability, complex purification, high cost, and insufficient mechanical properties. SDVGs with ECM-like structure and function, and good mechanical properties were rapidly prepared by optimizing common materials and preparation, which can improve their clinical prospects. Here, we rapidly prepared an electrospinning film-collagen/red blood cell membrane-genipin hydrogel tube (ES-C/Rm-G-ht, ID = 2 mm) by the combination of the cross-linking of genipin, plastic compression, electrospinning, and rolling without a biological adhesive, which had a shorter preparation time of less than 17 h compared to the existing ECM-based SDVGs (preparation time of 4–18 weeks). ES-C/Rm-G-ht exhibited a layered honeycomb-like structure and demonstrated the ECM-like functions to promote the proliferation and migration of endothelial cells, and prevent thrombus and inflammation. Furthermore, ES-C/Rm-G-ht, possessing sufficient mechanical strength, showed high patency, rapid endothelialization (95%), good regeneration of smooth muscle cell layers and ECM, and effective antistenosis capability after implantation in the rabbit’s carotid artery for 31 days. This work provides a straightforward, cost-effective, and promising strategy to prepare SDVGs with ECM-like structure and function, which is an ideal alternative for vascular grafts and autologous vessels in the current clinic.
Photoinduced Fröhlich Interaction-Driven Distinct Electron- and Hole-Polaron Behaviors in Hybrid Organic–Inorganic Perovskites by Ultrafast Terahertz Probes
Yuna Song - ,
Zhongtao Duan - ,
Lei Peng - ,
Juan Zhang - ,
Xun Zhu - ,
Qi Feng - ,
Zhihao Ji - ,
Yuqing Zou - ,
Jingying Zhang - ,
Ziyang Li - ,
Zongzhi Zhang - ,
Xiao-Lei Zhang - ,
Fengxian Xie *- ,
Hao Zhang *- , and
Qingyuan Jin *
The formation of large polarons resulting from the Fröhlich coupling of photogenerated carriers with the polarized crystal lattice is considered crucial in shaping the outstanding optoelectronic properties in hybrid organic–inorganic perovskite crystals. Until now, the initial polaron dynamics after photoexcitation have remained elusive in the hybrid perovskite system. Here, based on the terahertz time-domain spectroscopy and optical-pump terahertz probe, we access the nature of interplay between photoexcited unbound charge carriers and optical phonons in MAPbBr3 within the initial 5 ps after excitation and have demonstrated the simultaneous existence of both electron- and hole-polarons, together with the photogenerated carrier dynamic process. Two resonant peaks in the frequency-dependent photoconductivity are interpreted by the Drude–Smith–Lorentz model along with the ab initio excitation calculation, revealing that the electron-/hole-polaron is related to the vibration modes of the stretched/contracted Pb–Br bond. The red /blue shift of the corresponding peaks as the fingerprints of electron-/hole-polaron provides a channel for observing their dynamic behavior. Different from polarons with long lifetime (>300 ps) in single-crystalline grains, we observed in thin films the transient process from the formation to the dissociation of polarons occurring at timescales within ∼5 ps, resulting from the Mott phase transition for carriers at high concentrations. Moreover, the observation of the polaron dynamic process of the virtual state-assisted band gap transition (800 nm excitation) further reveals the competition of carriers cooling and polaron formation with photocarrier density. Our observations demonstrate a strategy for direct observation and manipulation of bipolar polaron transport in hybrid perovskites.
Individual Assembly of Radical Molecules on Superconductors: Demonstrating Quantum Spin Behavior and Bistable Charge Rearrangement
Chao Li *- ,
Vladislav Pokorný - ,
Martin Žonda *- ,
Jung-Ching Liu - ,
Ping Zhou - ,
Outhmane Chahib - ,
Thilo Glatzel - ,
Robert Häner - ,
Silvio Decurtins - ,
Shi-Xia Liu *- ,
Rémy Pawlak *- , and
Ernst Meyer *
This publication is Open Access under the license indicated. Learn More
High-precision molecular manipulation techniques are used to control the distance between radical molecules on superconductors. Our results show that the molecules can host single electrons with a spin 1/2. By changing the distance between tip and sample, a quantum phase transition from the singlet to doublet ground state can be induced. Due to local screening and charge redistribution, we observe either charged or neutral molecules, which couple in a sophisticated way, showing quantum spin behavior that deviates from the classical spins. Dimers at different separations show multiple Yu-Shiba-Rusinov peaks in tunneling spectroscopy of varying intensity, which are in line with the superconducting two-impurity Anderson model, where singlet (S = 0) and doublet (S = 1/2) ground states are found. The assembly of chains of 3, 4, and 5 molecules shows alternating charge patterns, where the edge molecules always host a charge/spin. The tetramer is observed in two configurations, where the neutral site is moved by one position. We show that these two configurations can be switched by the action of the probing tip in a nondestructive manner, demonstrating that the tetramer is an information unit, based on single-electron charge reorganization.
Two-Dimensional Nonvolatile Valley Spin Valve
Kai Huang - ,
Kartik Samanta - ,
Ding-Fu Shao - , and
Evgeny Y. Tsymbal *
A spin valve represents a well-established device concept in magnetic memory technologies, whose functionality is determined by electron transmission, controlled by the relative alignment of magnetic moments of the two ferromagnetic layers. Recently, the advent of valleytronics has conceptualized a valley spin valve (VSV)─a device that utilizes the valley degree of freedom and spin-valley locking to achieve a similar valve effect without relying on magnetism. In this study, we propose a nonvolatile VSV (n-VSV) based on a two-dimensional (2D) ferroelectric semiconductor where resistance of n-VSV is controlled by a ferroelectric domain wall between two uniformly polarized domains. Focusing on the 1T″ phase of MoS2, which is known to be ferroelectric down to a monolayer and using density functional theory combined with quantum transport calculations, we demonstrate that switching between the uniformly polarized state and the state with oppositely polarized domains separated by a domain wall results in a resistance change of as high as 107. This giant VSV effect occurs due to transmission being strongly dependent on matching (mismatching) the valley-dependent spin polarization in the two domains with the same (opposite) ferroelectric polarization orientations, when the chemical potential of 1T″-MoS2 lies within the spin-split valleys. The proposed n-VSV can be employed as a functional device for high-performance nonvolatile valleytronics.
Pick-and-Place Transfer of Arbitrary-Metal Electrodes for van der Waals Device Fabrication
Kaijian Xing *- ,
Daniel McEwen - ,
Yuefeng Yin - ,
Weiyao Zhao - ,
Abdulhakim Bake - ,
David Cortie - ,
Jingying Liu - ,
Thi-Hai-Yen Vu - ,
Yi-Hsun Chen - ,
James Hone - ,
Alastair Stacey - ,
Mark T. Edmonds - ,
Nikhil V. Medhekar - ,
Kenji Watanabe - ,
Takashi Taniguchi - ,
Qingdong Ou *- ,
Dong-Chen Qi *- , and
Michael S. Fuhrer *
Van der Waals electrode integration is a promising strategy to create nearly perfect interfaces between metals and 2D materials, with advantages such as eliminating Fermi-level pinning and reducing contact resistance. However, the lack of a simple, generalizable pick-and-place transfer technology has greatly hampered the wide use of this technique. We demonstrate the pick-and-place transfer of prefabricated electrodes from reusable polished hydrogenated diamond substrates without the use of any sacrificial layers due to the inherent low-energy and dangling-bond-free nature of the hydrogenated diamond surface. The technique enables transfer of arbitrary-metal electrodes and an electrode array, as demonstrated by successful transfer of eight different elemental metals with work functions ranging from 4.22 to 5.65 eV. We also demonstrate the electrode array transfer for large-scale device fabrication. The mechanical transfer of metal electrodes from diamond to van der Waals materials creates atomically smooth interfaces with no interstitial impurities or disorder, as observed with cross-section high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy. As a demonstration of its device application, we use the diamond transfer technique to create metal contacts to monolayer transition metal dichalcogenide semiconductors with high-work-function Pd, low-work-function Ti, and semimetal Bi to create n- and p-type field-effect transistors with low Schottky barrier heights. We also extend this technology to air-sensitive materials (trilayer 1T’ WTe2) and other applications such as ambipolar transistors, Schottky diodes, and optoelectronics. This highly reliable and reproducible technology paves the way for new device architectures and high-performance devices.
Active Inference and Artificial Spin Ice: Control Processes and State Selection
Robert L. Stamps *- ,
Rehana Begum Popy - , and
Johan van Lierop *
Theory and simulations are used to demonstrate implementation of a variational Bayes algorithm called “active inference” in interacting arrays of nanomagnetic elements. The algorithm requires stochastic elements, and a simplified model based on a magnetic artificial spin ice geometry is used to illustrate how nanomagnets can generate the required random dynamics. Examples of tracking and PID control are demonstrated and shown to be consistent with the original stochastic differential equation formulation of active inference. Interestingly, nonlinear response in the form of spikes and spike trains not predicted by the original theory can appear in the nanomagnet system for certain temperature regimes. A theoretical approach using a mean-field approximation for spin systems is proposed, which describes the transition to nonlinear response. Finally, the possibility to create simple magnetic arrays using realistic models is shown with micromagnetic simulations of a simple 17 element array of nanomagnets that include magnetic anisotropies, and exchange and dipolar interactions. Possible applications are simulated to illustrate how nanomagnetic arrays can be used as the stochastic element for feedback control of processes, investigation and control of magnetic state evolution, and as a method to optimize pulsed field magnetic switching protocols.
Atomically Precise Fabrication of Ultranarrow Zigzag CuTe Nanoribbons via Dimensional Regulation
Gefei Niu - ,
Jianchen Lu *- ,
Lei Gao *- ,
Jianqun Geng - ,
Wei Xiong - ,
Yong Zhang - ,
Hui Zhang - ,
Shicheng Li - ,
Yuhang Yang - ,
Boyu Fu - ,
Yi Zhang - , and
Jinming Cai *
Artificial dimension control has been playing a vital role in electronic structure manipulation and properties generation. However, systematic investigations into the dimensional regulation, such as transformation from two-dimensional (2D) materials to well-controlled one-dimensional (1D) ribbons, remain insufficient via molecular beam epitaxy. Here, high-quality ultranarrow zigzag CuTe nanoribbons are atomically precisely prepared via the dimensional regulation induced by adjusting the Te chemical potential, utilizing CuSe monolayer as the starting 2D template. Introducing Te atoms into the CuSe monolayer and subsequent annealing, Te atoms replace Se atoms within CuSe lattice. As the Te substitution ratio increases, strain accumulates and elongated nanopores emerge, which expand and interconnect to form 1D CuSe1–xTex (0 ≤ x ≤ 1) nanoribbons and ultimately coalesce into a 1D ultranarrow zigzag CuTe nanoribbons with a honeycomb lattice. The entire structural transformation is verified through scanning tunneling microscopy (STM) and density functional theory (DFT). Contrary to the 2D semiconducting nature of CuSe and CuSe1–xTex monolayers, newly formed 1D CuTe nanoribbons exhibit metallic properties. Intriguingly, DFT calculations further reveal spin-polarized states at the zigzag edges of CuTe nanoribbons. Our proposed dimensional regulation strategy from 2D materials to well-controlled 1D nanoribbons presents avenues for refining and enhancing the synthesis process.
Optical Metasurfaces for Biomedical Imaging and Sensing
Hongyoon Kim - ,
Heechang Yun - ,
Sebin Jeong - ,
Seokho Lee - ,
Eunseo Cho - , and
Junsuk Rho *
Optical metasurfaces, arrays of nanostructures engineered to manipulate light, have emerged as a transformative technology in both research and industry due to their compact design and exceptional light control capabilities. Their strong light–matter interactions enable precise wavefront modulation, polarization control, and significant near-field enhancements. These unique properties have recently driven their application in biomedical fields. In particular, metasurfaces have led to breakthroughs in biomedical imaging technologies, such as achromatic imaging, phase imaging, and extended depth-of-focus imaging. They have also advanced cutting-edge biosensing technologies, featuring high-quality factor resonators and near-field enhancements. As the demand for device miniaturization and system integration increases, metasurfaces are expected to play a pivotal role in the development of next-generation biomedical devices. In this review, we explore the latest advancements in the use of metasurfaces for biomedical applications, with a particular focus on imaging and sensing. Additionally, we discuss future directions aimed at transforming the biomedical field by leveraging the full potential of metasurfaces to provide compact, high-performance solutions for a wide range of applications.
Volatile Sieving Using Architecturally Designed Nanochannel Lamellar Membranes in Membrane Desalination
Zhigao Zhu - ,
Xiaohui Wang - ,
Yujun Zhou - ,
Junwen Qi - ,
Yue Yang - ,
Wei Wang *- , and
Jiansheng Li *
Thermally driven membrane desalination processes have garnered significant interest for their potential in the treatment of hypersaline wastewater. However, achieving high rejection rates for volatiles while maintaining a high water flux remains a considerable challenge. Herein, we propose a thermo-osmosis-evaporation (TOE) system that utilizes molecular intercalation-regulated graphene oxide (GO) as the thermo-osmotic selective permeation layer, positioned on a hydrophobic poly(vinylidene fluoride) fibrous membrane serving as the thermo-evaporation layer. By carefully constructing architectural interlaminar nanochannels of GO membranes via simultaneously confining small molecules to enlarge the interlayer spacing and incorporating polymers within the GO interlayers to create a dense network, the resultant demonstrates a rejection rate of 100% for NaCl and 97.41% for volatile phenylamine, with a water permeance of 63.80 L m–2 h–1 at a temperature difference of 40 °C, outperforming previously reported GO-based membranes. Simulation and calculation results reveal that the polymer network between the GO interlayers facilitates the high-efficiency separation of nonvolatile ions and volatile molecules, while the enlarged channels reduce vapor diffusion resistance. This study provides valuable insights for the design of advanced membranes and serves as inspiration for the continued development of the TOE system for complex hypersaline wastewater treatment.
Bionic Luminescent Sensors Based on Covalent Organic Frameworks: Auditory, Gustatory, and Olfactory Information Monitoring for Multimode Perception
Xueping Quan - ,
Kai Zhu - ,
Yinsheng Liu - , and
Bing Yan *
The synthesis of covalent organic frameworks (COFs) with excellent luminescent properties and their effective application in the field of bionic sensing remain a formidable challenge. Herein, a series of COFs with different numbers of hydroxyl groups are successfully synthesized, and the number of hydroxyl groups on the benzene-1,3,5-tricarbaldehyde (BTA) linker influences the properties of the final COFs. The COF (HHBTA-OH) prepared with hydrazine hydrate (HH) and BTA containing one hydroxyl group as the ligands exhibits the best fluorescent performance. MA@HHBTA-OH is formed by the reaction of HHBTA-OH with meldrum’s acid (MA) and has its extremely high hydrophilicity, dispersibility, and strong red fluorescence, which can imitate the human gustatory system to detect bitter substances. MA@HHBTA-OH was combined with agarose (AG) to construct a MA@HHBTA-OH@AG film for assessing food freshness. In addition, an acoustic MA@HHBTA-OH@MF sensor is fabricated by integrating luminescent MA@HHBTA-OH with melamine foam (MF) through a strong hydrogen bond. MA@HHBTA-OH@MF functions like an eardrum and recognizes sound through pressure waves with excellent mechanical sensing performance. In summary, biomimetic luminescent sensors based on MA@HHBTA-OH were successfully constructed, which can monitor auditory, gustatory, and olfactory information to achieve the multimode perception of sound, bitter substances, and food freshness.
Superconductive Coupling Effects in Selectively Grown Topological Insulator-Based Three-Terminal Junctions
Gerrit Behner *- ,
Abdur Rehman Jalil - ,
Alina Rupp - ,
Hans Lüth - ,
Detlev Grützmacher - , and
Thomas Schäpers *
This publication is Open Access under the license indicated. Learn More
The combination of an ordinary s-type superconductor with three-dimensional topological insulators creates a promising platform for fault-tolerant topological quantum computing circuits based on Majorana braiding. The backbone of the braiding mechanism are three-terminal Josephson junctions. It is crucial to understand the transport in these devices for further use in quantum computing applications. We present low-temperature measurements of topological insulator-based three-terminal Josephson junctions fabricated by a combination of selective-area growth of Bi0.8Sb1.2Te3 and shadow mask evaporation of Nb. This approach allows for the in situ fabrication of Josephson junctions with an exceptional interface quality, important for the study of the proximity-effect. We map out the transport properties of the device as a function of bias currents and prove the coupling of the junctions by the observation of a multiterminal geometry-induced diode effect. We find good agreement of our findings with a resistively and capacitively shunted junction network model.
Controlled Nitrogen Release by Hydroxyapatite Nanomaterials in Leaves Enhances Plant Growth and Nitrogen Uptake
Bhaskar Sharma - ,
Hagay Kohay - ,
Sandeep Sharma - ,
Marina Youngblood - ,
Jarad P. Cochran - ,
Jason M. Unrine - ,
Olga V. Tsyusko - ,
Gregory V. Lowry - , and
Juan Pablo Giraldo *
Nitrogen fertilizer delivery inefficiencies limit crop productivity and contribute to environmental pollution. Herein, we developed Zn- and Fe-doped hydroxyapatite nanomaterials (ZnHAU, FeHAU) loaded with urea (∼26% N) through hydrogen bonding and metal–ligand interactions. The nanomaterials attach to the leaf epidermal cuticle and localize in the apoplast of leaf epidermal cells, triggering a slow N release at acidic conditions (pH 5.8) that promote wheat (Triticum aestivum) growth and increased N uptake compared to conventional urea fertilizers. ZnHAU and FeHAU exhibited prolonged N release compared to urea in model plant apoplast fluid pH in vitro (up to 2 days) and in leaf membranes in plants (up to 10 days) with a high N retention (32% to 53%) under simulated high rainfall events (50 mm). Foliar N delivery doses of up to 4% as ZnHAU and FeHAU did not induce toxicity in plant cells. The foliar-applied ZnHAU and FeHAU enhanced fresh and dry biomass by ∼214% and ∼161%, and N uptake by ∼108% compared to foliar-applied urea under low soil N conditions in greenhouse experiments. Controlled N release by leaf-attached nanomaterials improves N delivery and use efficiency in crop plants, creating nanofertilizers with reduced environmental impact.
Preclinical and First-in-Human Study of a Compact Radionuclide Labeled Self-Assembly Nanomedicine for Chemo-Radio-Theranostics of Cancer
Hehe Xiong - ,
Rongxi Wang - ,
Heng Zhang - ,
Qianyu Zhang - ,
Yatong Qin - ,
Chao Du - ,
Xinyi Zhang - ,
Jinmin Ye - ,
Changrong Shi - ,
Huaxiang Shen - ,
Zhaohui Zhu *- ,
Zijian Zhou *- ,
Xiaoyuan Chen *- , and
Jingjing Zhang *
The emerging combination of chemotherapy and radionuclide therapy has been actively investigated to overcome the limitations of monotherapy and augment therapeutic efficacy. However, it remains a challenge to design a single delivery vehicle that can incorporate chemotherapeutics and radionuclides into a compact structure. Here, a chelator DOTA- or NOTA-modified Evans blue conjugated camptothecin molecule (EB-CPT) nanoprodrug was synthesized, which could self-assemble into nanoparticles due to its inherent amphiphilicity. The nanoparticles could then be effectively labeled with therapeutic radionuclide lutetium-177 (177Lu) or diagnostic radionuclides gallium-68 (68Ga)/copper-64 (64Cu) with high radiolabeling efficiency and radiochemical stability. Impressively, a single-dose chemoradiation therapy of [177Lu]Lu-DOTA-EB-CPT plus EB-CPT effectively inhibited tumor growth in HCT116 tumor-bearing mice compared to the respective individual therapeutic approach. The [64Cu]Cu-NOTA-EB-CPT nanoparticles also exhibited excellent in vivo characteristics including favorable blood circulation properties and prolonged tumor retention in tumor-bearing mice. The safety, feasibility, tolerability, and biodistribution of [68Ga]Ga-NOTA-EB-ss-CPT were also preliminarily characterized in a first-in-human study. This study presents a simple but robust EB-CPT radiopharmaceutical that leverages EB as an albumin binder to strike a delicate balance between enhanced tumor accumulation, safety, and diagnostic efficacy, facilitating an integrated theranostic strategy within a single molecular structure. This radionuclide-labeled EB-CPT nanomedicine presents a step toward clinical translation of the combination of chemotherapy and radiotheranostics.
January 12, 2025
Permeable, Stretchable, and Recyclable Cellulose Aerogel On-Skin Electronics for Dual-Modal Sensing and Personal Healthcare
Shuai Liu - ,
Wenwen Li - ,
Xinyi Wang - ,
Liang Lu *- ,
Yue Yao - ,
Shuyu Lai - ,
Yunqi Xu - ,
Junjie Yang - ,
Zhihao Hu - ,
Xinglong Gong *- ,
Ken Cham-Fai Leung - , and
Shouhu Xuan *
Flexible on-skin electronics present tremendous popularity in intelligent electronic skins (e-skins), healthcare monitoring, and human-machine interfaces. However, the reported e-skins can hardly provide high permeability, good stretchability, and large sensitivity and are limited in long-term stability and efficient recyclability when worn on the human body. Herein, inspired from the human skin, a permeable, stretchable, and recyclable cellulose aerogel-based electronic system is developed by sandwiching a screen-printed silver sensing layer between a biocompatible CNF/HPC/PVA (cellulose nanofiber/hydroxypropyl cellulose/poly(vinyl alcohol)) aerogel hypodermis layer and a permeable polyurethane layer as the epidermis layer. The cellulose aerogel displays a high tensile strength of 1.14 MPa and tensile strain of 43.5% while maintaining good permeability. The cellulose aerogel-based electronics embrace appealing sensing performances with high sensitivity (gauge factor ≈ 238), ultralow detection limit (0.1%), and fast response time (18 ms) under strain stimulus. Owing to the disconnection and reconnection of microcracks in the sensing layer, both strain/humidity sensing and thermal healthcare can be easily achieved. The permeable electronics can be further integrated into an electronic mask for patient-centered healthcare with a power supply system, switching control device, and wireless Bluetooth module. Moreover, the prepared electronic system enables long-term wearing on human skin without skin irritation, and all components of the electronics can be recaptured/reused in water. This material strategy highlights the potential of next-generation on-skin electronics with high permeability and good environmental friendliness.
van der Waals Photonic Bipolar Junction Transistors Capable of Simultaneously Discerning Wavelength Bands and Dual-Function Chip Application
Zhengrui Zhu - ,
Liwei Liu - ,
Shaozhi Deng *- , and
Ningsheng Xu *
The exponential growth of the Internet of Things (IoTs) has led to the widespread deployment of millions of sensors, crucial for the sensing layer’s perception capabilities. In particular, there is a strong interest in intelligent photonic sensing. However, the current photonic sensing device and chip typically offer limited functionality, and the devices providing their power take up excessive amounts of space. There is a pressing need for smart, multifunctional sensing chips with the capability of intelligent recognition. Here, we propose and demonstrate the functionalities of a two-dimensional van der Waals photonic bipolar junction transistor (2D-vdW photonic BJT) in simultaneous sensing and discerning different wavelength bands of light. Also, a dual-function chip application is given. The optoelectronic detection characteristics in the vision-near-infrared (vis-NIR) band and photovoltaic characteristics are systematically studied. It exhibits negative photoconductivity (NPC) for the 1064 nm laser while maintaining positive photoconductivity (PPC) for the 638 and 1550 nm lasers. Also, the electrical tunable response is realized. Moreover, the function of this chip under real-application conditions has shown its efficacy in applications such as detecting dim light with ∼10 lx illuminance, identifying wavelength bands, and generating power photovoltaically. This work provides a solution for the interconnection of everything.
Temperature-Directed Morphology Transformation Method for Precision-Engineered Polymer Nanostructures
Valentin A. Bobrin *- ,
Surya E. Sharma-Brymer - , and
Michael J. Monteiro *
With polymer nanoparticles now playing an influential role in biological applications, the synthesis of nanoparticles with precise control over size, shape, and chemical functionality, along with a responsive ability to environmental changes, remains a significant challenge. To address this challenge, innovative polymerization methods must be developed that can incorporate diverse functional groups and stimuli-responsive moieties into polymer nanostructures, which can then be tailored for specific biological applications. By combining the advantages of emulsion polymerization in an environmentally friendly reaction medium, high polymerization rates due to the compartmentalization effect, chemical functionality, and scalability, with the precise control over polymer chain growth achieved through reversible-deactivation radical polymerization, our group developed the temperature-directed morphology transformation (TDMT) method to produce polymer nanoparticles. This method utilized temperature or pH responsive nanoreactors for controlled particle growth and with the added advantages of controlled surface chemical functionality and the ability to produce well-defined asymmetric structures (e.g., tadpoles and kettlebells). This review summarizes the fundamental thermodynamic and kinetic principles that govern particle formation and control using the TDMT method, allowing precision-engineered polymer nanoparticles, offering a versatile and an efficient means to produce 3D nanostructures directly in water with diverse morphologies, high purity, high solids content, and controlled surface and internal functionality. With such control over the nanoparticle features, the TDMT-generated nanostructures could be designed for a wide variety of biological applications, including antiviral coatings effective against SARS-CoV-2 and other pathogens, reversible scaffolds for stem cell expansion and release, and vaccine and drug delivery systems.
Dual Strategies Based on Golgi Apparatus/Endoplasmic Reticulum Targeting and Anchoring for High-Efficiency siRNA Delivery and Tumor RNAi Therapy
Yashi Wang - ,
Sheng Yin - ,
Dan He - ,
Yujia Zhang - ,
Ziyan Dong - ,
Zhipeng Tian - ,
Jiayu Li - ,
Fang Chen - ,
Yang Wang - ,
Man Li *- , and
Qin He *
Endolysosomal degradation of small interfering RNA (siRNA) significantly reduces the efficacy of RNA interference (RNAi) delivered by nonviral systems. Leveraging Golgi apparatus/endoplasmic reticulum (Golgi/ER) transport can help siRNA bypass the endolysosomal degradation pathway, but this approach may also result in insufficient siRNA release and an increased risk of Golgi/ER-mediated exocytosis. To address these challenges, we developed two distinct strategies using a nanocomplex of cell-penetrating poly(disulfide)s and chondroitin sulfate, which enhances targeted internalization, Golgi transport, and rapid cytoplasmic release of loaded siRNA. In the first strategy, monensin synergy was found to enhance RNAi by inhibiting both exocytosis and autophagic degradation. In the second strategy, a “directed sorting” approach based on KDEL peptide-mediated retrograde transport was introduced. By conjugation of the KDEL peptide to chondroitin sulfate, Golgi-to-ER transport was promoted, reducing “random” Golgi/ER-related exocytosis. These two strategies operate alternatively to achieve high-efficiency RNAi with a significant therapeutic potential. Notably, in a mouse melanoma model using anti-Bcl-2 siRNA, the strategies achieved tumor inhibition rates of 87.1 and 90.1%, respectively. These two strategies, based on “targeting” and “anchoring” Golgi/ER, provide potent solutions to overcome the challenges of cellular internalization, intracellular release, and exocytosis in efficient siRNA delivery.
January 11, 2025
Giant Purcell Broadening and Lamb Shift for DNA-Assembled Near-Infrared Quantum Emitters
Sachin Verlekar - ,
Maria Sanz-Paz - ,
Mario Zapata-Herrera - ,
Mauricio Pilo-Pais - ,
Karol Kołątaj - ,
Ruben Esteban *- ,
Javier Aizpurua - ,
Guillermo P. Acuna *- , and
Christophe Galland *
Controlling the light emitted by individual molecules is instrumental to a number of advanced nanotechnologies ranging from super-resolution bioimaging and molecular sensing to quantum nanophotonics. Molecular emission can be tailored by modifying the local photonic environment, for example, by precisely placing a single molecule inside a plasmonic nanocavity with the help of DNA origami. Here, using this scalable approach, we show that commercial fluorophores may experience giant Purcell factors and Lamb shifts, reaching values on par with those recently reported in scanning tip experiments. Engineering of plasmonic modes enables cavity-mediated fluorescence far detuned from the zero-phonon-line (ZPL)─at detunings that are up to 2 orders of magnitude larger than the fluorescence line width of the bare emitter and reach into the near-infrared. Our results point toward a regime where the emission line width can become dominated by the excited-state lifetime, as required for indistinguishable photon emission, bearing relevance to the development of nanoscale, ultrafast quantum light sources and to the quest toward single-molecule cavity QED. In the future, this approach may also allow the design of efficient quantum emitters at infrared wavelengths, where standard organic sources have a reduced performance.
Rational Design of Dual-Targeted Nanomedicines for Enhanced Vascular Permeability in Low-Permeability Tumors
Mingsheng Zhu - ,
Qiqi Liu - ,
Zhengbang Chen - ,
Jinming Liu - ,
Zhixuan Zhang - ,
Jingwei Tian - ,
Xiangyang Wang - ,
Xiong Yang - ,
Quan Chen - ,
Xinglu Huang *- , and
Jie Zhuang *
Designing dual-targeted nanomedicines to enhance tumor delivery efficacy is a complex challenge, largely due to the barrier posed by blood vessels during systemic delivery. Effective transport across endothelial cells is, therefore, a critical topic of study. Herein, we present a synthetic biology-based approach to engineer dual-targeted ferritin nanocages (Dt-FTn) for understanding receptor-mediated transport across tumor endothelial cells. By leveraging a genetically engineered logic-gated strategy, we coassembled various Dt-FTn in E. coli with tunable ratios of RGD-targeting and intrinsic TfR1-targeting ligands. These Dt-FTn constructs were employed to investigate the interaction between receptor-mediated vascular permeability and dual-targeted nanomedicines in low-permeability tumors. Through machine learning-based single vessel analysis, we uncovered the crucial role of dual-receptor expression profiles in determining the vascular transport of dual-targeted nanomedicines in tumors with low permeability. Using a patient-derived colon cancer model, we demonstrated a proof-of-concept that the optimal proportions of dual ligands in these nanomedicines can be customized based on tumor cell receptor expression profiles. This study provides valuable insights and guiding principles for the rational design of dual-targeted nanomedicines for tumor-targeted delivery.
Shaping the Emission Directivity of Single Quantum Dots in Dielectric Nanodisks Exploiting Mie Resonances
Cristina Cruciano - ,
Davide Rocco - ,
Armando Genco *- ,
Andrea Tognazzi - ,
Andrea Locatelli - ,
Luca Carletti - ,
Alexey Fedorov - ,
Chiara Trovatello - ,
Giuseppe Di Blasio - ,
Ilaria Bargigia - ,
Charalambos Louca - ,
Paolo Gubian - ,
Giulio Tavani - ,
Luca Lovisolo - ,
Artur Tuktamyshev - ,
Lucio C. Andreani - ,
Matteo Galli - ,
Giulio Cerullo - ,
Giuseppe Leo - ,
Stefano Sanguinetti - ,
Costantino De Angelis - , and
Monica Bollani
Manipulating the optical landscape of single quantum dots (QDs) is essential to increase the emitted photon output, enhancing their performance as chemical sensors and single-photon sources. Micro-optical structures are typically used for this task, with the drawback of a large size compared to the embedded single emitters. Nanophotonic architectures hold the promise to modify dramatically the emission properties of QDs, boosting light–matter interactions at the nanoscale, in ultracompact devices. Here, we investigate the interplay between gallium arsenide (GaAs) single QDs and aluminum gallium arsenide (AlGaAs) nanostructures, capitalizing on the Kerker condition for precise control of the QD emission directivity. An extensive analysis of the photoluminescence spectra of several QDs embedded in nanodisks revealed a pronounced directivity enhancement due to the Kerker effect, confirmed by theoretical simulations, resulting in a 14-fold increase of emitted intensity. Angle-resolved spectroscopy experiments also proved that the integration of GaAs QDs within nanostructures determines a precise angled emission, offering a distinctive avenue for manipulating the spatial characteristics of emitted light by exploiting Mie resonances. This work contributes to the optimization of QD integration in nanostructures and suggests potential improvements for applications in optical communications.
Atomic Gap-State Engineering of MoS2 for Alkaline Water and Seawater Splitting
Tao Sun *- ,
Tong Yang - ,
Wenjie Zang - ,
Jing Li - ,
Xiaoyu Sheng - ,
Enzhou Liu - ,
Jiali Li - ,
Xiao Hai - ,
Huihui Lin - ,
Cheng-Hao Chuang - ,
Chenliang Su - ,
Maohong Fan - ,
Ming Yang - ,
Ming Lin - ,
Shibo Xi - ,
Ruqiang Zou *- , and
Jiong Lu *
Transition-metal dichalcogenides (TMDs), such as molybdenum disulfide (MoS2), have emerged as a generation of nonprecious catalysts for the hydrogen evolution reaction (HER), largely due to their theoretical hydrogen adsorption energy close to that of platinum. However, efforts to activate the basal planes of TMDs have primarily centered around strategies such as introducing numerous atomic vacancies, creating vacancy–heteroatom complexes, or applying significant strain, especially for acidic media. These approaches, while potentially effective, present substantial challenges in practical large-scale deployment. Here, we report a gap-state engineering strategy for the controlled activation of S atom in MoS2 basal planes through metal single-atom doping, effectively tackling both efficiency and stability challenges in alkaline water and seawater splitting. A versatile synthetic methodology allows for the fabrication of a series of single-metal atom-doped MoS2 materials (M1/MoS2), featuring widely tunable densities with each dopant replacing a Mo site. Among these (Mn1, Fe1, Co1, and Ni1), Co1/MoS2 demonstrates outstanding HER performance in both alkaline and seawater alkaline media, with overpotentials at a mere 159 and 164 mV at 100 mA cm–2, and Tafel slopes at 41 and 45 mV dec–1, respectively, which surpasses all reported TMD-based nonprecious materials and benchmark Pt/C catalysts in HER efficiency and stability during seawater splitting, which can be attributed to an optimal gap-state modulation associated with sulfur atoms. Experimental data correlating doping density and dopant identity with HER performance, in conjunction with theoretical calculations, also reveal a descriptor linked to near-Fermi gap state modulation, corroborated by the observed increase in unoccupied S 3p states.
January 10, 2025
Decoupling Individual Host Response and Immune Cell Engager Cytotoxic Potency
Cristina Gonzàlez Gutierrez - ,
Adrien Aimard - ,
Martine Biarnes-Pélicot - ,
Brigitte Kerfelec - ,
Pierre-Henri Puech - ,
Philippe Robert - ,
Francesco Piazza *- ,
Patrick Chames *- , and
Laurent Limozin *
Immune cell engagers are molecular agents, usually antibody-based constructs, engineered to recruit immune cells against cancer cells and kill them. They are versatile and powerful tools for cancer immunotherapy. Despite the multiplication of engagers tested and accepted in the clinic, how molecular and cellular parameters influence their actions is poorly understood. In particular, disentangling the respective roles of host immune cells and engager biophysical characteristics is needed to improve their design and efficiency. Focusing here on harnessing antibody-dependent Natural Killer cell cytotoxicity, we measure the efficiency of 6 original bispecific antibodies (bsAb), associating an anti-HER2 nanobody and an anti-CD16 nanobody. In vitro cytotoxicity data using primary human NK cells on different target cell lines exposing different antigen densities were collected, exhibiting a wide range of bsAb dose response. In order to rationalize our observations, we introduce a simple multiscale model, postulating that the density of bsAb bridging the two cells is the main parameter triggering the cytotoxic response. We introduce two microscopic parameters: the surface cooperativity describing bsAb affinity at the bridging step and the threshold of bridge density determining the donor-dependent response. Both parameters permit ranking Abs and donors and predicting bsAb potency as a function of antibodies bulk affinities and receptor surface densities on cells. Our approach thus provides a general way to decouple donor response from immune engager characteristics, rationalizing the landscape of molecule design.
Surface Circular Photogalvanic Effect in Tl–Pb Monolayer Alloys on Si(111) with Giant Rashba Splitting
Ibuki Taniuchi - ,
Ryota Akiyama *- ,
Rei Hobara - , and
Shuji Hasegawa
We have found that surface superstructures made of “monolayer alloys” of Tl and Pb on Si(111), having giant Rashba effect, produce nonreciprocal spin-polarized photocurrent via circular photogalvanic effect (CPGE) by obliquely shining circularly polarized near-infrared (IR) light. CPGE is here caused by the injection of in-plane spin into spin-split surface-state bands, which is observed only on Tl–Pb alloy layers but not on single-element Tl nor Pb layers. In the Tl–Pb monolayer alloys, despite their monatomic thickness, the magnitude of CPGE is comparable to or even larger than the cases of many other spin-split thin-film materials. A model analysis has provided the relative permittivity ε* of the monolayer alloys to be ∼1.0, which is because the monolayer exists at a transition region between vacuum and the substrate. The present result opens the possibility that we can optically manipulate the spins of electrons even on monolayer materials.
Dual-Anion-Rich Polymer Electrolytes for High-Voltage Solid-State Lithium Metal Batteries
Yangqian Zhang - ,
Han Liu - ,
Fangyan Liu - ,
Shuoxiao Zhang - ,
Mengyuan Zhou - ,
Yaqi Liao - ,
Ying Wei - ,
Weixia Dong - ,
Tianyi Li - ,
Chen Liu *- ,
Qi Liu - ,
Henghui Xu - ,
Gang Sun - ,
Zhenbo Wang - ,
Yang Ren *- , and
Jiayi Yang *
Solid polymer electrolytes (SPEs) are promising candidates for lithium metal batteries (LMBs) owing to their safety features and compatibility with lithium metal anodes. However, the inferior ionic conductivity and electrochemical stability of SPEs hinder their application in high-voltage solid-state LMBs (HVSSLMBs). Here, a strategy is proposed to develop a dual-anion-rich solvation structure by implementing ferroelectric barium titanate (BTO) nanoparticles (NPs) and dual lithium salts into poly(vinylidene fluoride) (PVDF)-based SPEs for HVSSLMBs. The BTO NPs regulate the spatial structure of PVDF segments, enhancing the local built-in electric field in the SPEs, which, in turn, facilitates the dissolution and dissociation of lithium salts. This contributes to the dual-anion-rich solvation structure with an enhanced steric effect, which significantly improves Li+ transport kinetics and electrochemical stability. The designed PVDF-based SPE achieves a high ionic conductivity of 4.1 × 10–4 S cm–1 and a transference number of 0.70 at 25 °C. The Li//Li symmetric cells deliver an excellent critical current density of 2.4 mA cm–2 and maintain a stable Li plating/stripping process for over 5000 h. After 1000 cycles at 2C, the LiFePO4//Li cells achieve a discharge capacity of 108.3 mAh g–1. Furthermore, the LiNi0.8Co0.1Mn0.1O2 (NCM811)//Li cells present high capacity retention after 300 cycles at 1C with a cutoff voltage of 4.4 V. The NCM811/Graphite pouch batteries exhibit excellent cycling and safety performance. This work illustrates that the synergistic integration of functional nanoparticles with multiple lithium salts holds significant potential for the development of high-voltage SPEs.
Maternal Exposure to Polystyrene Nanoplastics Disrupts Spermatogenesis in Mouse Offspring by Inducing Prdm14 Overexpression in Undifferentiated Spermatogonia
Sheng Ma - ,
Sisi Li - ,
Shengyao Jiang - ,
Lirui Wang - ,
Dian Zhan - ,
Manyi Xiong - ,
Yanping Jiang - ,
Qixian Huang - ,
Haozhan Kui - , and
Xinhong Li *
Undifferentiated spermatogonia (Undiff-SPG) plays a critical role in maintaining continual spermatogenesis. However, the toxic effects and molecular mechanisms of maternal exposure to nanoplastics on offspring Undiff-SPG remain elusive. Here, we utilized a multiomics combined cytomorphological approach to explore the reproductive toxicity and mechanisms of polystyrene nanoplastics (PS-NPs) on offspring Undiff-SPG in mice after maternal exposure. The results indicated that PS-NPs decreased testosterone levels and reduced sperm concentration and quality in offspring male mice through maternal exposure. Moreover, PS-NPs could enter offspring Undiff-SPG, increase ROS levels, and decrease the viability of Undiff-SPG. According to the transcriptomics and proteomics analyses, PS-NPs caused offspring male mice Undiff-SPG inflammation by increasing the expression of Tnfsf18/Nlrp6. Mechanistically, we found that inflammation induced overexpression of the transcription factor Prdm14 in Undiff-SPG, which suppressed the expression of Ccdc33 and Tcirg1. Additionally, PS-NPs disrupted offspring spermatogenesis by inhibiting the Osbp2/Zcwpw1/Dhps expression. Furthermore, PS-NPs reduced the Undiff-SPG autophagic flux by reducing the expression of Igbp1/Gabarapl2. In conclusion, maternal exposure to PS-NPs caused inflammation in offspring Undiff-SPG, which resulted in Prdm14 overexpression that could disrupt spermatogenesis and normal autophagy.
Conductive Eutectogels Fabricated by Dialdehyde Xylan/Liquid Metal-Initiated Rapid Polymerization for Multi-Response Sensors and Self-Powered Applications
Jiyou Yang - ,
Yin Yan - ,
Lingzhi Huang - ,
Mingguo Ma - ,
Mingfei Li - ,
Feng Peng - ,
Weiwei Huan *- , and
Jing Bian *
Conductive eutectogels have emerged as candidates for constructing functional flexible electronics as they are free from the constraints posed by inherent defects associated with solvents and feeble network structures. Nevertheless, developing a facile, environmentally friendly, and rapid polymerization strategy for the construction of conductive eutectogels with integrated multifunctionality is still immensely challenging. Herein, a conductive eutectogel is fabricated through a one-step dialdehyde xylan (DAX)/liquid metal (LM)-initiated polymerization of a deep eutectic solvent. DAX acts as a stabilizer for the preparation of LM nanodroplets and plays a crucial role in facilitating ultrafast gelation (less than 2 min) by virtue of its reducing dialdehyde groups. Notably, this fabrication strategy obviates the use of toxic chemical initiators and cross-linkers. The resultant eutectogels exhibit extremely high stretchability (2860%), desirable self-healing ability, high conductivity (0.72 S m–1), biocompatibility, excellent environmental stability, and exceptional responsiveness to tensile strain (GF = 4.08) and temperature (TCR = 5.35% K–1). Benefiting from these integrated features, the conductive eutectogels serve as multifunctional flexible sensors for human motion recognition and temperature monitoring. Furthermore, the eutectogel serves as a pliable electrode in the assembly of a triboelectric nanogenerator (TENG), designed to harvest mechanical energy, convert it into stable electrical outputs, and enable self-powered sensing. This study offers an approach to fabricating multifunctional integrated conductive eutectogels, making it a step closer to the development of intelligent flexible electronics.
Vaccine Specifically for Immunocompromised Individuals against Superbugs
Litong Wang - ,
Yitao Zhang - ,
Jiaxin Huang - ,
Sijie Wang - ,
Shuhan Ji - ,
Shenyu Wang - ,
Meixing Shi - ,
Junlei Zhang - ,
Yingying Shi - ,
Zhenyu Luo - ,
Zhaolei Jin - ,
Xindong Jiang - ,
Qingpo Li - ,
Fuchun Yang *- ,
Jian You *- , and
Lihua Luo *
Immunocompromised populations, including cancer patients, elderly individuals, and those with chronic diseases, are the primary targets of superbugs. Traditional vaccines are less effective due to insufficient or impaired immune cells. Inspired by the “vanguard” effect of neutrophils (NE) during natural infection, this project leverages the ability of NE to initiate the NETosis program to recruit monocytes and DC cells, designing vaccines that can rapidly recruit immune cells and enhance the immune response. The PLGA microsphere vaccine platform (MSV) with a high level of safety contains whole-bacterial antigens both internally and externally, providing initial and booster effects through programmed distribution and release of antigens after a single injection. Experimental data indicate that immunizing mice with a mixture of MSV and NE induces the formation of spontaneous gel-like neutrophil extracellular traps (NETs) at the inoculation site. These NETs recruit immune cells and prevent the diffusion of vaccine components, thereby reducing damage from bacterial toxins and enhancing vaccine biosafety. This strategy shows excellent efficacy against MRSA-induced infections in not only healthy but also immunocompromised mice.
High-Resolution Mapping of Photocatalytic Activity by Diffusion-Based and Tunneling Modes of Photo-Scanning Electrochemical Microscopy
Tianyu Bo - ,
Debjit Ghoshal - ,
Logan M. Wilder - ,
Elisa M. Miller *- , and
Michael V. Mirkin *
This publication is Open Access under the license indicated. Learn More
Semiconductor nanomaterials and nanostructured interfaces have important technological applications, ranging from fuel production to electrosynthesis. Their photocatalytic activity is known to be highly heterogeneous, both in an ensemble of nanomaterials and within a single entity. Photoelectrochemical imaging techniques are potentially useful for high-resolution mapping of photo(electro)catalytic active sites; however, the nanoscale spatial resolution required for such experiments has not yet been attained. In this article, we report photoreactivity imaging of two-dimensional MoS2 photocatalysts by two modes of photoscanning electrochemical microscopy (photo-SECM): diffusion and tunneling-based modes. Diffusion-based (feedback mode) photo-SECM is used to map the electron transfer and hydrogen evolution rates on mixed-phase MoS2 nanosheets and MoS2 chemical vapor deposition (CVD)-grown triangles. An extremely high resolution of photoelectrochemical imaging (about 1–2 nm) by the tunneling mode of the photo-SECM is demonstrated.
Voices of Nanomedicine: Blueprint Guidelines for Collaboration in Addressing Global Unmet Medical Needs
Rajendra Prasad *- ,
Arnab Ghosh - ,
Vinay Patel - ,
Berney Peng - ,
Bárbara B. Mendes - ,
Eaint Honey Aung Win - ,
Lucia Gemma Delogu - ,
Joyce Y. Wong - ,
Kristin J. Pischel - ,
Jayesh R. Bellare - ,
Amnon Bar-Shir - ,
Avnesh S. Thakor - ,
Wolfgang J. Parak - ,
Zaver M. Bhujwalla - ,
Yu Shrike Zhang - ,
Nagavendra Kommineni - ,
Vince M. Rotello - ,
Weibo Cai - ,
Twan Lammers - ,
Teri W. Odom - ,
Govindarajan Padmanaban - ,
Dan Peer - ,
Jonathan F. Lovell - ,
Rohit Srivastava *- ,
Robert Langer - , and
João Conde *
The “Voices” under this Perspective underline the importance of interdisciplinary collaboration and partnerships across several disciplines, such as medical science and technology, medicine, bioengineering, and computational approaches, in bridging the gap between research, manufacturing, and clinical applications. Effective communication is key to bridging team gaps, enhancing trust, and resolving conflicts, thereby fostering teamwork and individual growth toward shared goals. Drawing from the success of the COVID-19 vaccine development, we advocate the application of similar collaborative models in other complex health areas such as nanomedicine and biomedical engineering. The role of digital technology and big data in healthcare innovation is highlighted along with the necessity for specialized education in collaborative practices. This approach is decisive in advancing healthcare solutions, leading to improved treatment and patient outcomes.
Role of Competing Magnetic Exchange on Non-Collinear to Collinear Magnetic Ordering and Skyrmion Stabilization in Centrosymmetric Hexagonal Magnets
Dola Chakrabartty - ,
Mihir Sahoo - ,
Amit Kumar - ,
Sk Jamaluddin - ,
Bimalesh Giri - ,
Hitesh Chhabra - ,
Kalpataru Pradhan *- , and
Ajaya K. Nayak *
Topological magnetic skyrmions with helicity state degrees of freedom in centrosymmetric magnets possess great potential for advanced spintronics applications and quantum computing. Till date, the skyrmion study in this class of materials mostly remains focused to collinear ferromagnets with uniaxial magnetic anisotropy. Here, we present a combined theoretical and experimental study on the competing magnetic exchange-induced evolution of noncollinear magnetic ground states and its impact on the skyrmion formation in a series of centrosymmetric hexagonal noncollinear magnets, MnFe1–xCoxGe. We show that by engineering the Fe/Co ratio, the system progressively transforms from a noncollinear magnetic state with in-plane antiferromagnetic ordering in MnFeGe to a collinear ferromagnetic (FM) spin arrangement in MnFe0.2Co0.8Ge. We utilize Lorentz transmission electron microscopy, neutron diffraction experiments, and micromagnetic simulations to demonstrate the role of competing magnetic exchange-induced in-plane magnetic moment in the formation of nontopological type-II magnetic bubbles in the system. However, skyrmions with degenerate helicity states are found to be stable magnetic entities in the case of the perfect uniaxial magnetic anisotropy system. The present study offers a great opportunity to tune the skyrmion phase in centrosymmetric magnets by intrinsically designing the magnetic ground state, thereby providing a unique platform for realizing skyrmion-based spintronics devices.
Resolving Artifacts and Improving the Detection Limit in Circular Differential Scattering Measurement of Chiral and Achiral Gold Nanorods
Hao Li - ,
Kyle Van Gordon - ,
Heng Zhang - ,
Le Wang - ,
Ningneng Hu - ,
Luis M. Liz-Marzán *- , and
Weihai Ni *
Circular differential scattering (CDS) spectroscopy has been developed as a powerful method for the characterization of the optical activity of individual plasmonic nanostructures and their complexes with chiral molecules. However, standard measurement setups often result in artifacts that have long raised concerns on the interpretation of spectral data. In fact, the detection limit of CDS setups is constrained by the high level of artifacts, to ±10%. We address this issue by means of a detailed theoretical description of changes in the polarization state when circularly polarized light is reflected at a dark-field condenser. As a result, we propose a modified CDS configuration based on sequentially placing the quarter-wave plate and linear polarizer within the detection optical path, to analyze the circular polarization state of the light scattered by individual particles. Extensive analysis demonstrates a detection limit of ±1.5% for the modified configuration, which is significantly lower than that for the conventional setup. As a standard system for CDS measurements, both achiral and chiral gold nanorods (AuNRs) were characterized using both setups. With achiral AuNRs, linear dichroism (LD) artifacts in the conventional setup are found to originate from LD present in the excitation light and are only present if anisotropic excitation is produced as a result of the misalignment of the excitation light to the condenser. With chiral AuNRs, CDS spectra recorded with the conventional setup depend on the orientation of the chiral AuNRs with respect to the x-axis of the microscope and are reversed compared to those on the colloid and measured in the modified configuration. The results are in good agreement with theoretical simulations for both configurations.
Digital Profiling of Tumor Extracellular Vesicle-Associated RNAs Directly from Unprocessed Blood Plasma
Elizabeth Maria Clarissa - ,
Sumit Kumar *- ,
Juhee Park - ,
Mamata Karmacharya - ,
In-Jae Oh *- ,
Mi-Hyun Kim - ,
Jeong-Seon Ryu - , and
Yoon-Kyoung Cho *
Tumor-derived extracellular vesicle (tEV)-associated RNAs hold promise as diagnostic biomarkers, but their clinical use is hindered by the rarity of tEVs among nontumor EVs. Here, we present EV-CLIP, a highly sensitive droplet-based digital method for profiling EV RNA. EV-CLIP utilizes the fusion of EVs with charged liposomes (CLIPs) in a microfluidic chip. Optimized CLIP surface charge enables exceptional sensitivity and selectivity for EV-derived miRNAs and mRNAs. This approach streamlines detection with minimal plasma volume (20 μL) and eliminates the need for prior EV isolation or RNA preparation, preventing loss of EVs or RNA. In testing with 83 patient samples, EV-CLIP detected EGFR L858R and T790M mutations with high AUC values of 1.0000 and 0.9784, respectively. Its success in serial monitoring during chemotherapy highlights its potential for precise quantification of rare EV subpopulations, facilitating the exploration of single EV RNA content and enhancing understanding of diverse EV populations in various disease states.
Highly Efficient Blue Light-Emitting Diodes Enabled by Gradient Core/Shell-Structured Perovskite Quantum Dots
Bo Xu *- ,
Shichen Yuan - ,
Linqin Wang - ,
Xiansheng Li - ,
Zhuang Hu - , and
Haibo Zeng *
Room temperature (RT) synthesized mixed bromine and chlorine CsPbBrxCl3–x perovskite quantum dots (Pe-QDs) offer notable advantages for blue quantum dot light-emitting diodes (QLEDs), such as cost-effective processing and narrow luminescence peaks. However, the efficiency of blue QLEDs using these RT-synthesized QDs has been limited by inferior crystallinity and deep defect presence. In this study, we demonstrate a precise approach to constructing high-quality gradient core–shell (CS) structures of CsPbBrxCl3–x QD through anion exchange. Characterization shows that these CS-QDs exhibit a type-I band alignment with a high bromine concentration in the core and a high chlorine concentration in the shell. This unique configuration results in a larger exciton binding energy and reduced defect density, leading to enhanced exciton radiative recombination. Consequently, QLEDs using CS-QDs achieve an external quantum efficiency (EQE) of 16.28%, a maximum luminance of 8423.35 cd/m2, and improved operational stability, surpassing the 12.80% EQE of reference QLEDs made with homogeneous structured QDs (HS-QDs). These findings present a strategy for developing high-quality RT-synthesized blue CS-QDs, marking a significant advancement in the field of efficient pure-blue QLEDs.
Substructure-Specific Antibodies Against Fentanyl Derivatives
Asheley Chapman - ,
Minghao Xu - ,
Michelle Schroeder - ,
Jason M. Goldstein - ,
Asiya Chida - ,
Joo R. Lee - ,
Xiaoling Tang - ,
Rebekah E. Wharton *- , and
M. G. Finn *
This publication is Open Access under the license indicated. Learn More
Structural variants of the synthetic opioid fentanyl are a major threat to public health. Following an investigation showing that many derivatives are poorly detected by commercial lateral flow and related assays, we created hapten conjugate vaccines using an immunogenic virus-like particle carrier and eight synthetic fentanyl derivatives designed to mimic the structural features of several of the more dangerous analogues. Immunization of mice elicited strong antihapten humoral responses, allowing the screening of hundreds of hapten-specific hybridomas for binding strength and specificity. A panel of 13 monoclonal IgG antibodies were selected, each showing a different pattern of recognition of fentanyl structural variations, and all proving to be highly efficient at capturing parent fentanyl compounds in competition ELISA experiments. These results provide antibody reagents for assay development as well as a demonstration of the power of the immune system to create binding agents capable of both broad and specific recognition of small-molecule targets.
On-Demand Selection of the Latent Domain Orientation in Spray-Deposited Block Copolymer Thin Films
Semih Cetindag - ,
Beatrice Bellini - ,
Ruipeng Li - ,
Esther H.R. Tsai - ,
Dmytro Nykypanchuk - , and
Gregory S. Doerk *
With their ability to self-assemble spontaneously into well-defined nanoscale morphologies, block copolymer (BCP) thin films are a versatile platform to fabricate functional nanomaterials. An important challenge to wider deployment of BCPs in nanofabrication is combining precise control over the nanoscale domain orientation in BCP assemblies with scalable deposition techniques that are applicable to large-area, curved, and flexible substrates. Here, we show that spray-deposited smooth films of a nominally disordered BCP exhibit latent orientations, which can be prescriptively selected by controlling solvent evaporation during spray casting. Subsequent solvent vapor annealing triggers assembly toward highly ordered cylindrical morphologies along the pathway determined by solvent evaporation in the prior spray deposition stage. Faster evaporation promotes assembly of vertically oriented cylinders spanning the entire film thickness (100–300 nm). In comparison, slow solvent evaporation permits intermicellar aggregation and incipient cylinder formation in solution, which induces horizontal cylinder assembly upon annealing. The evaporatively controlled latent orientation mechanism presented herein elucidates how nonequilibrium phenomena during casting govern successive self-assembly pathways and facilitates a versatile method to dictate the domain orientation of BCP thin films on demand on flexible and highly curved substrates or in distinct pattern areas on the same substrate.
Inhalable siRNA Targeting IL-11 Nanoparticles Significantly Inhibit Bleomycin-Induced Pulmonary Fibrosis
Shengting Dong - ,
Huapan Fang *- ,
Junjie Zhu - ,
Zhiqiang Wu - ,
Yi Liu - ,
Jiafei Zhu - ,
Benting Ma - ,
Qian Chen - , and
Yang Yang *
For idiopathic pulmonary fibrosis (IPF), interleukin 11 (IL-11) is a pivotal cytokine that stimulates the transformation of fibroblasts into myofibroblasts, thus accelerating the progression of pulmonary fibrosis. Here, we develop an innovative inhalable small interfering RNA (siRNA) delivery system termed PEI-GBZA, which demonstrates impressive efficiency in loading siIL-11 targeting IL-11 (siIL-11) and substantially suppresses the differentiation of fibroblasts into myofibroblasts and epithelial-mesenchymal transition (EMT), reduces neutrophil and macrophage recruitment, and ultimately relieves the established fibrotic lesions in the IPF model. PEI-GBZA is prepared by modifying low-molecular-weight polyethylenimine (PEI) with 4-guanidinobenzoic acid (GBZA). The resulting PEI-GBZA may effectively encapsulate siIL-11 through a variety of interactions such as hydrophobic, hydrogen bonding, and electrostatic interactions, creating stable carrier/siIL-11 nanoparticles (PEI-GBZA/siIL-11 NPs). Upon inhalation, PEI-GBZA/siIL-11 NPs demonstrate effective retention in fibrotic lesions, leading to a marked mitigation of disease progression in a bleomycin-induced pulmonary fibrosis model. Impressively, this inhalation therapy exhibits negligible systemic toxicity. This work provides a universal and noninvasive RNA therapeutic delivery platform that holds significant promise for respiratory diseases. The potential for clinical application of this platform is substantial, offering a frontier for the treatment of IPF and potentially other pulmonary disorders.
On-Surface Synthesis and Characterization of Radical Spins in Kagome Graphene
Rémy Pawlak *- ,
Khalid N. Anindya - ,
Outhmane Chahib - ,
Jung-Ching Liu - ,
Paul Hiret - ,
Laurent Marot - ,
Vincent Luzet - ,
Frank Palmino - ,
Frédéric Chérioux - ,
Alain Rochefort - , and
Ernst Meyer *
This publication is Open Access under the license indicated. Learn More
Flat bands in Kagome graphene might host strong electron correlations and frustrated magnetism upon electronic doping. However, the porous nature of Kagome graphene opens a semiconducting gap due to quantum confinement, preventing its fine-tuning by electrostatic gates. Here we induce zero-energy states into a semiconducting Kagome graphene by inserting π-radicals at selected locations. We utilize the on-surface reaction of tribromotrioxoazatriangulene molecules to synthesize carbonyl-functionalized Kagome graphene on Au(111), thereafter modified in situ by exposure to atomic hydrogen. Atomic force microscopy and tunneling spectroscopy unveil the stepwise chemical transformation of the carbonyl groups into radicals, which creates local magnetic defects of spin state S = 1/2 and zero-energy states as confirmed by density functional theory. The ability to imprint local magnetic moments opens up prospects to study the interplay between topology, magnetism, and electron correlation in Kagome graphene.
Enabling High-Voltage and Long Lifespan Sodium Batteries via Single-Crystal Layer-Structured Oxide Cathode Material
Dong-Run Yang - ,
Liu Chen - ,
Xuan-Wen Gao - ,
Zhiwei Zhao - ,
Qing-Song Lai - ,
Hong Chen - ,
Yutong Long - ,
Qinfen Gu - ,
Zhao-Meng Liu - , and
Wen-Bin Luo *
Manganese-based layer-structured transition metal oxides are considered promising cathode materials for future sodium batteries owing to their high energy density potential and industrial feasibility. The grain-related anisotropy and electrode/electrolyte side reactions, however, constrain their energy density and cycling lifespan, particularly at high voltages. Large-sized single-crystal O3-typed Na[Ni0.3Mn0.5Cu0.1Ti0.1]O2 was thus designed and successfully synthesized toward high-voltage and long-lifespan sodium batteries. The grain-boundary-free single-crystal structure and unidirectional Na+ diffusion channels enable a faster Na+ diffusion rate and high electronic conductivity. Meanwhile, the large-area exposed (003) crystal plane can not only exhibit a higher energy barrier for electrode–electrolyte side reactions but also alleviate the interlayer sliding and structural collapse during charge–discharge processes. The lattice oxygen in contact with the electrolyte was stabilized, and the TMO6 octahedral structure integrity was maintained as well. A high specific capacity of 160.1 mAh g–1 at a current density of 0.1 C was demonstrated. Coupled with hard carbon as the anode, the full cell can also demonstrate an excellent capacity and cycling stability, achieving a high specific capacity of 141.1 mAh g–1 at 0.1 C. After 100 cycles at 2 C, the capacity retention rate is 97.3%.
Capacitorless Dynamic Random Access Memory with 2D Transistors by One-Step Transfer of van der Waals Dielectrics and Electrodes
Jianmiao Guo - ,
Ziyuan Lin - ,
Xiangli Che - ,
Cong Wang - ,
Tianqing Wan - ,
Jianmin Yan - ,
Ye Zhu - , and
Yang Chai *
Dynamic random access memory (DRAM) has been a cornerstone of modern computing, but it faces challenges as technology scales down, particularly due to the mismatch between reduced storage capacitance and increasing OFF current. The capacitorless 2T0C DRAM architecture is recognized for its potential to offer superior area efficiency and reduced refresh rate requirements by eliminating the traditional capacitor. The exploration of two-dimensional (2D) materials further enhances scaling possibilities, though the absence of dangling bonds complicates the deposition of high-quality dielectrics. Here, we present a hexagonal boron nitride (h-BN)-assisted process for one-step transfer of van der Waals dielectrics and electrodes in 2D transistors with clean interfaces. The transferred aluminum oxide (Al2O3), formed by oxidizing aluminum (Al), exhibits exceptional flatness and uniformity, preserving the intrinsic properties of the 2D semiconductors without introducing doping effects. The MoS2 transistor exhibits an extremely low interface trap density of about 3 × 1011 cm–2 eV–1 and a leakage current density down to 10–7 A cm–2, which enables effective charge storage at the gate stack. This method allows for the simultaneous fabrication of two damage-free MoS2 transistors to form a capacitorless 2T0C DRAM cell, enhancing compatibility with 2D materials. The ultralow leakage current optimizes data retention and power efficiency. The fabricated 2T0C DRAM exhibits a rapid write speed of 20 ns, long data retention exceeding 1,000 s, and low energy consumption of approximately 0.2 fJ per write operation. Additionally, it demonstrates 3-bit storage capability and exceptional stability across numerous write/erase cycles.
January 9, 2025
In Silico-Guided Discovery of Polysaccharide Derivatives as Adjuvants in Nanoparticle Vaccines for Cancer Immunotherapy
Zan Cui - ,
Chenyu Shi - ,
Ran An - ,
Yan Tang - ,
Yinping Li - ,
Xueting Cao - ,
Xukai Jiang - ,
Chang-Cheng Liu *- ,
Min Xiao *- , and
Li Xu *
Cancer vaccines utilizing nanoparticle (NP) structures that integrate antigens and adjuvants to enhance delivery and stimulate immune responses are emerging as a promising avenue in cancer immunotherapy. However, the development of cancer vaccines has been significantly hindered by the low immunogenicity of tumor antigens. To address this challenge, substantial efforts have been made in developing innovative adjuvants to elicit effective immune responses. In this study, we develop a NP cancer vaccine assisted by a polysaccharide derivative adjuvant, designed through a computational strategy, to evoke effective antigen-specific antitumor immunity. Using TLR4 as the putative receptor, we conducted a comprehensive evaluation of a prescreening library consisting of 34 inulin derivatives through docking and molecular dynamics simulation. Consequently, a new derivative, benzoylated inulin (InBz), is selected as the most promising TLR4 agonist. The adjuvant effect of InBz is evaluated by fabricating InBz NPs encapsulating the model antigen ovalbumin (OVA). In vitro, InBz-OVA NPs effectively activate the TLR4 signaling pathways and facilitate dendritic cell maturation, thereby enhancing the antigen delivery and presentation. In vivo, InBz-OVA NPs outperform a commercial aluminum-based adjuvant, elicit robust antibody titers, induce antigen-specific cytotoxic T lymphocytes, and achieve significant tumor suppression in murine models. Besides, the adjuvant effects of other representative derivatives, namely, acetylated and chloroacetylated inulin, with moderate and low potential from the library, are also chemically synthesized and experimentally evaluated and found to be in agreement with computational predictions, confirming the credibility of the strategy. This study provides an effective platform for the pursuit of efficient polysaccharide-based vaccine adjuvants.
Formation Cycle Control for Enhanced Structural Stability of Ni-Rich LiNixCoyMn1-x-yO2 Cathodes
Sungmin Na - ,
Rena Oh - ,
Jungyeon Song - ,
Myoung-Jae Lee - ,
Kwangjin Park *- , and
Gyeong-Su Park *
Nickel-rich NCM cathode materials promise lithium-ion batteries with a high energy density. However, an increased Ni fraction in the cathode leads to complex phase transformations with electrode–electrolyte side reactions, which cause rapid capacity fading. Here, we show that an initial formation cycle at 0.1 C with a higher cutoff voltage (≥4.35 V) increases the stability of Ni-rich NCM (LiNi0.88Co0.08Mn0.04O2) particles during cycling at 1 C. We unveil that the formation of intragranular nanovoids is directly associated with the initial formation cycle at a lower charging cutoff voltage when oxygen vacancies are introduced at the Ni-rich NCM particle surface, due to irreversible electrolyte decomposition at the cathode–electrolyte interface. Nanovoid evolution of the Ni-rich NCM particles after 50 cycles increases the NiO-like rock salt phase; it results in intragranular cracks, which cause structural instability via heterogeneous phase distribution. This work demonstrates the importance of controlling Ni-rich NCM surface chemistry from the initial formation cycle to achieve better cycling stability.
Local Environment-Modulated f–f Transition in Unit-Cell-Sized Lanthanide Ultrathin Nanostructures
Hao Fu - ,
Ziyun Zhong - ,
Zhong Liang - ,
Yong Jiang - ,
Di Qiu - ,
Mengzhen Zhang - ,
Mengdie Jin - ,
Zhichao Zeng - ,
Leilei Yin - , and
Yaping Du *
The regulation of the f–f transition is the basis of utilizing the abundant optical properties of lanthanide (Ln), of which the key is to modulate the local environment of Ln ions. Here, we constructed Eu(III)-based unit-cell-sized ultrathin nanowires (UCNWs) with red luminescence and polymer-like behavior, which appears as an ideal carrier for regulating f–f transition. The f–f transition of Eu(III) in UCNWs could be precisely regulated through various ligands. It is the unusual surface states that make the UCNWs exhibit greater electric dipole strength and better sensitivity to various ligands compared with the carefully constructed ultrathin nanosheets. In addition, the possibility of regulating f–f transition in UCNWs through energy transfer and a high entropy strategy was also revealed. Finally, a temperature-dependent universal fluorescent ink was prepared based on UCNWs, which provides ideas for intelligent flexible fluorescent materials.
Two-Dimensional Material-Based Nanofluidic Devices and Their Applications
Yangjun Cui - ,
Long Gao - ,
Cuifeng Ying *- ,
Jianguo Tian *- , and
Zhibo Liu *
Nanofluidics is an interdisciplinary field of study that bridges hydrodynamics, statistical physics, chemistry, materials science, biology, and other fields to investigate the transport of fluids and ions on the nanometric scale. The progress in this field, however, has been constrained by challenges in fabricating nanofluidic devices suitable for systematic investigations. Recent advances in two-dimensional (2D) materials have revolutionized the development of nanofluids. Their ultrathin structure and photothermoelectric response make it possible to achieve the scale control, friction limitation, and regulatory response, all of which are challenging to achieve with traditional solid materials. In this review, we provide a comprehensive overview of the preparation methods and corresponding structures of three types of 2D material-based nanofluidic devices, including nanopores, nanochannels, and membranes. We highlight their applications and recent advances in exploring physical mechanisms, detecting biomolecules (DNA, protein), developing iontronics devices, improving ion/gas selectivity, and generating osmotic energy. We discuss the challenges facing 2D material-based nanofluidic devices and the prospects for future advancements in this field.
Ultraelastic Lead Halide Perovskite Films via Direct Laser Patterning
Annan Hu - ,
Lihui Hou - ,
Yang Yue - ,
Siu Fung Yu - ,
Xue Yu *- , and
Ting Wang *
The precise patterning of elastic semiconductors holds encouraging prospects for unlocking functionalities and broadening the scope of optoelectronic applications. Here, perovskite films with notable elasticity capable of stretching over 250% are successfully fabricated by using a continuous-wave (CW) laser-patterning technique. Under CW laser irradiation, perovskite nanoparticles (NPs) undergo meticulous crystallization within the thermoplastic polyurethane (TPU) matrix, which yields the capability of an unparalleled stretch behavior. Furthermore, the strategic integration of β-phase poly(vinylidene fluoride) (β-PVDF) introduces a highly ordered dipolar framework, augmenting the crystallization dynamics of perovskite NPs during the laser-patterning process, thereby elevating the patterning efficiency and film quality. Furthermore, full-spectrum visible perovskite films that possess high transparency, high resolution, and adequate stability are achieved through the precise tuning of halide components, thereby emphasizing the impressive versatility of the high-elasticity printing technique. Our findings are meaningful for the direct patterning of high-precision, highly elastic semiconductors, finding a way for advancements in stretchable photonic and optoelectronic devices.
Catalytic Assembly of Peptides Mediated by Complex Coacervates
Wang Li - ,
Yang Zhou - ,
Tianyi Tong - ,
Sheng He - ,
Congsen Wang - ,
Xinran Zhang - ,
Xiao-Yu Cao - ,
Liulin Yang *- , and
Zhong-Qun Tian
The assembly of peptides is generally mediated by liquid–liquid phase separation, which enables control over assembly kinetics, final structure, and functions of peptide-based supramolecular materials. Modulating phase separation can alter the assembly kinetics of peptides by changing solvents or introducing external fields. Herein, we demonstrate that the assembly of peptides can be effectively catalyzed by complex coacervates. The negatively charged sodium alginate (SA) can form complex coacervates with the positively charged KLVFFAE (Aβ16–22, abbreviated as KE) peptide, thereby lowering the nucleation barrier and promoting the assembly of the peptide. As the binding affinity of SA-KE and the dosage of SA decrease, the system shifts from a relatively inefficient template-induced assembly to a highly efficient catalytic assembly before ultimately reverting to slow spontaneous assembly. Therefore, both the affinity as well as the stoichiometry do not follow the intuitive rule that “more is better”, but rather there exists an optimal value that maximizes the rate of assembly.
Direct View of Gate-Tunable Miniband Dispersion in Graphene Superlattices Near the Magic Twist Angle
Zhihao Jiang - ,
Dongkyu Lee - ,
Alfred J. H. Jones - ,
Youngju Park - ,
Kimberly Hsieh - ,
Paulina Majchrzak - ,
Chakradhar Sahoo - ,
Thomas S. Nielsen - ,
Kenji Watanabe - ,
Takashi Taniguchi - ,
Philip Hofmann - ,
Jill A. Miwa - ,
Yong P. Chen - ,
Jeil Jung - , and
Søren Ulstrup *
This publication is Open Access under the license indicated. Learn More
Superlattices from twisted graphene mono- and bilayer systems give rise to on-demand many-body states such as Mott insulators and unconventional superconductors. These phenomena are ascribed to a combination of flat bands and strong Coulomb interactions. However, a comprehensive understanding is lacking because the low-energy band structure strongly changes when an electric field is applied to vary the electron filling. Here, we gain direct access to the filling-dependent low-energy bands of twisted bilayer graphene (TBG) and twisted double bilayer graphene (TDBG) by applying microfocused angle-resolved photoemission spectroscopy to in situ gated devices. Our findings for the two systems are in stark contrast: the doping-dependent dispersion for TBG can be described in a simple model, combining a filling-dependent rigid band shift with a many-body-related bandwidth change. In TDBG, on the other hand, we find a complex behavior of the low-energy bands, combining nonmonotonous bandwidth changes and tunable gap openings, which depend on the gate-induced displacement field. Our work establishes the extent of electric field tunability of the low-energy electronic states in twisted graphene superlattices and can serve to underpin the theoretical understanding of the resulting phenomena.
Attoampere Level Leakage Current in Chemical Vapor Deposition-Grown Monolayer MoS2 Dynamic Random-Access Memory in Trap-Assisted Tunneling Limit
Jisoo Seok - ,
Jae Eun Seo - ,
Dae Kyu Lee - ,
Joon Young Kwak *- , and
Jiwon Chang *
MoS2, one of the most researched two-dimensional semiconductor materials, has great potential as the channel material in dynamic random-access memory (DRAM) due to the low leakage current inherited from the atomically thin thickness, high band gap, and heavy effective mass. In this work, we fabricate one-transistor-one-capacitor (1T1C) DRAM using chemical vapor deposition (CVD)-grown monolayer (ML) MoS2 in large area and confirm the ultralow leakage current of approximately 10–18 A/μm, significantly lower than the previous report (10–15 A/μm) in two-transistor-zero-capacitor (2T0C) DRAM based on a few-layer MoS2 flake. Through rigorous analysis of leakage current considering thermionic emission, tunneling at the source/drain, Shockley–Read–Hall recombination, and trap-assisted tunneling (TAT) current, the TAT current is identified as the primary source of leakage current. These findings highlight the potential of CVD-grown ML MoS2 to extend the retention time in DRAM and provide a deep understanding of the leakage current sources in MoS2 1T1C DRAM for further optimization to minimize the leakage current.
Polarization-Dependent Plasmon-Induced Doping and Strain Effects in MoS2 Monolayers on Gold Nanostructures
Matheus Fernandes Sousa Lemes *- ,
Ana Clara Sampaio Pimenta - ,
Gaston Lozano Calderón - ,
Marcelo A. Pereira-da-Silva - ,
Alessandra Ames - ,
Marcio Daldin Teodoro - ,
Guilherme Migliato Marega - ,
Riccardo Chiesa - ,
Zhenyu Wang - ,
Andras Kis - , and
Euclydes Marega Junior *
This publication is Open Access under the license indicated. Learn More
Monolayers of transition-metal dichalcogenides, such as MoS2, have attracted significant attention for their exceptional electronic and optical properties, positioning them as ideal candidates for advanced optoelectronic applications. Despite their strong excitonic effects, the atomic-scale thickness of these materials limits their light absorption efficiency, necessitating innovative strategies to enhance light–matter interactions. Plasmonic nanostructures offer a promising solution to overcome those challenges by amplifying the electromagnetic field and also introducing other mechanisms, such as hot electron injection. In this study, we investigate the vibrational and optical properties of MoS2 monolayer deposited on gold substrates and gratings, emphasizing the role of strain and plasmonic effects using conventional spectroscopic techniques. Our results reveal significant biaxial strain in the supported regions and a uniaxial strain gradient in the suspended ones, showing a strain-induced exciton and carrier funneling effect toward the center of the nanogaps. Moreover, we observed an additional polarization-dependent doping mechanism in the suspended regions. This effect was attributed to localized surface plasmons generated within the slits, as confirmed by numerical simulations, which may decay nonradiatively into hot electrons and be injected into the monolayer. Photoluminescence measurements further demonstrated a polarization-dependent trion-to-A exciton intensity ratio, supporting the hypothesis of additional plasmon-induced doping. These findings provide a comprehensive understanding of the strain-mediated funneling effects and plasmonic interactions in hybrid MoS2/Au nanostructures, offering valuable insights for developing high-efficiency photonic devices and quantum technologies, including polarization-sensitive detectors and excitonic circuits.
Surface and Interfacial Engineering for Multifunctional Nanocarbon Materials
Yuxuan Sun - ,
Chuanbing Li - ,
Dan Liu - ,
Fei Zhang - ,
Jie Xue - , and
Qingbin Zheng *
Multifunctional materials are accelerating the development of soft electronics with integrated capabilities including wearable physical sensing, efficient thermal management, and high-performance electromagnetic interference shielding. With outstanding mechanical, thermal, and electrical properties, nanocarbon materials offer ample opportunities for designing multifunctional devices with broad applications. Surface and interfacial engineering have emerged as an effective approach to modulate interconnected structures, which may have tunable and synergistic effects for the precise control over mechanical, transport, and electromagnetic properties. This review presents a comprehensive summary of recent advances empowering the development of multifunctional nanocarbon materials via surface and interfacial engineering in the context of surface and interfacial engineering techniques, structural evolution, multifunctional properties, and their wide applications. Special emphasis is placed on identifying the critical correlations between interfacial structures across nanoscales, microscales, and macroscales and multifunctional properties. The challenges currently faced by the multifunctional nanocarbon materials are examined, and potential opportunities for applications are also revealed. We anticipate that this comprehensive review will promote the further development of soft electronics and trigger ideas for the interfacial design of nanocarbon materials in multidisciplinary applications.
Versatile Thermally Activated Delayed Fluorescence Material Enabling High Efficiencies in both Photodynamic Therapy and Deep-Red/NIR Electroluminescence
Hui Wang - ,
Yijian Gao - ,
Jiaxiong Chen - ,
Xiao-Chun Fan - ,
Yi-Zhong Shi - ,
Jia Yu - ,
Kai Wang *- ,
Shengliang Li *- ,
Chun-Sing Lee *- , and
Xiaohong Zhang *
Thermally activated delayed fluorescence (TADF) materials have received increasing attention from organic electronics to other related fields, such as bioapplications and photocatalysts. However, it remains a challenging task for TADF emitters to showcase the versatility concurrent with high performance in multiple applications. Herein, we first present such a proof-of-concept TADF material, namely, QCN-SAC, through strategically manipulating exciton dynamics. On the one hand, QCN-SAC displays obvious aggregate-induced deep-red/near-infrared emission with a high radiative rate beyond 107 s–1, thereby demonstrating nearly 100% exciton utilization under oxygen-free conditions. In a QCN-SAC-based nondoped organic light-emitting diode (OLED), a superb external quantum efficiency of 16.4% can be reached with a peak at 708 nm. On the other hand, QCN-SAC also exhibits a high intersystem crossing rate over 108 s–1 without leveraging the heavy-atom effect, which makes QCN-SAC-based nanoparticles perform well in boosting reactive oxygen species generation for imaging-guided photodynamic therapy (PDT). This work presents a fundamental principle for designing high-performance all-in-one TADF molecules for OLED and PDT applications. This discovery holds promise for advancing the development of versatile TADF materials with a range of uses in the near future.
The Effects of Morphology and Hydration on Anion Transport in Self-Assembled Nanoporous Membranes
Christopher W. Johnson - ,
Lizhu Zhang - ,
Keira E. Culley - ,
Sol Mi Oh - ,
Douglas L. Gin - ,
Geoffrey M. Geise - ,
Amish J. Patel - ,
Karen I. Winey - , and
Chinedum O. Osuji *
Ordered nanoporous polymer membranes offer opportunities for systematically probing the mechanisms of ion transport under confinement and for realizing useful materials for electrochemical devices. Here, we examine the impact of morphology and ion hydration on the transport of hydroxide and bromide anions in nanostructured polymer membranes with 1 nm scale pores. We use aqueous lyotropic self-assembly of an amphiphilic monomer, with a polymerizable surfactant to create direct hexagonal (HI) and gyroid mesophases. UV-induced cross-linking leads to the formation of nanoporous polymers with water continuous channels. The membranes are mechanically robust and chemically durable, resisting degradation during extended exposure to 1 M NaOH solutions. We use a combination of electrochemical impedance spectroscopy, pulsed-field gradient NMR spectroscopy, and molecular simulations to elucidate anion and water transport. The as-prepared hexagonal systems display higher conductivity and lower activation energies for both anions relative to the gyroid system. When compared at equivalent hydration, however, gyroid and hexagonal membranes show similar activation energies, with nearly identical conductivities at ambient temperatures. Both ionic conductivity and water diffusivity increase with increasing hydration. The water uptake as a function of relative humidity for the hexagonal and gyroid mesophases ultimately dictates the water diffusion and magnitude of the ionic conductivity, with the hexagonal system showing overall higher capacity for hydration and thus faster ion transport. The durability of these materials under aggressive alkaline conditions and their relatively high hydroxide ion conductivity suggest that these nanostructured polymers could be of interest as membranes for alkaline fuel cells.
Spin Canting Promoted Manipulation of Exchange Bias in a Perpendicular Coupled Fe3GaTe2/CrSBr Magnetic van der Waals Heterostructure
Kaipeng Ni - ,
Jiayuan Zhou - ,
Yang Chen - ,
Huanghuang Cheng - ,
Ziyi Cao - ,
Junming Guo - ,
Aljoscha Söll - ,
Xingyuan Hou - ,
Lei Shan - ,
Zdenek Sofer - ,
Mengmeng Yang - ,
Yang Yue - ,
Jinsong Xu - ,
Mingliang Tian - ,
Wenshuai Gao *- ,
Yuxuan Jiang *- ,
Yong Fang *- , and
Xue Liu *
Recently, two-dimensional (2D) van der Waals (vdW) magnetic materials have emerged as a promising platform for studying exchange bias (EB) phenomena due to their atomically flat surfaces and highly versatile stacking configurations. Although complex spin configurations between 2D vdW interfaces introduce challenges in understanding their underlying mechanisms, they can offer more possibilities in realizing effective manipulations. In this study, we present a spin-orthogonal arranged 2D Fe3GaTe2 (FGaT)/CrSBr vdW heterostructure, realizing the EB effect with the bias field as large as 1730 Oe at 2 K. Interestingly, this structure induces a positive EB under low cooling field, in contrast to conventional phenomena. Moreover, by employing asymmetric field sweeping methods, we effectively manipulate the zero-field cooling EB of the device with a switchable sign and a tunable magnitude. Thus, these findings not only elucidate a distinct mechanism analysis for EB phenomena with perpendicular coupled spin configurations but also hold promise for promoting contemporary 2D spintronic device applications.
Probing Single-Cell Adhesion Kinetics and Nanomechanical Force with Surface Plasmon Resonance Imaging
Dehong Yang - ,
Xiaoyin Liu - ,
Jinbiao Ma - ,
Baiqi Cui - ,
Yunxiao Wang - ,
Jiahao Xu - ,
Yunrui Zhang - ,
Haiying Ding - ,
Di Wang - ,
Qingjun Liu - , and
Fenni Zhang *
Single cell adhesion plays a significant role in numerous physiological and pathological processes. Real-time imaging and quantification of single cell adhesion kinetics and corresponding cell–substrate mechanical interaction forces are crucial for elucidating the cellular mechanisms involved in tissue formation, immune responses, and cancer metastasis. Here, we present the development of a plasmonic-based nanomechanical sensing and imaging system (PNMSi) for the real-time measurement of single cell adhesion kinetics and associated nanomechanical forces with plasmonic tracking and monitoring of cell–substrate interactions and the accompanying nanoscale fluctuations. Both the slow binding and dynamic nanomechanical interaction processes were tracked and analyzed with a thermodynamic model to determine the adhesion kinetic parameters and quantity the mechanical forces. To demonstrate the capabilities of the PNMSi platform, we examined single cell binding interactions across four different surface modifications, and obvious alterations in binding kinetics and corresponding nanomechanical forces were observed, influenced by surface charges and interfacial hydrophilicity. Additionally, we investigated changes in mechanical interaction forces of single cells during cytoskeleton modification, revealing the cross-linking-induced cell adhesion changes. Furthermore, to demonstrate the application capability of the system, the adhesion profiling of primary tumor and metastatic tumor cells was explored, and obvious alterations were observed in the kinetic forces of single cell–substrate interaction. The PNMSi platform facilitates high-throughput single cell adhesion imaging and the quantification of adhesion interaction kinetics and nanomechanical forces with high sensitivity and serves as a promising platform for identifying biomarkers for tumor metastasis and for screening potential therapeutic agents.
Multifaceted Catalytic Glucose Depletion and Reactive Oxygen Species-Scavenging Nanoenzyme Composite Hydrogel for Facilitating Diabetic Bone Regeneration
Shuyao Liu - ,
Ming Lu - ,
Meihua Zhang - ,
Xiaoqing Sun - ,
Bin Luo *- , and
Yao Wu *
Regeneration of diabetic bone defects remains a formidable challenge due to the chronic hyperglycemic state, which triggers the accumulation of advanced glycation end products (AGEs) and reactive oxygen species (ROS). To address this issue, we have engineered a bimetallic metal–organic framework-derived Mn@Co3O4@Pt nanoenzyme loaded with alendronate and Mg2+ ions (termed MCPtA) to regulate the hyperglycemic microenvironment and recover the osteogenesis/osteoclast homeostasis. Notably, the Mn atom substitution in the Co3O4 nanocrystalline structure could modulate the electronic structure and significantly improve the SOD/CAT catalytic activity for ROS scavenging. By integration with GOx-like Pt nanoparticles, the MCPtA achieved effective multiple cascade catalytic performance that facilitated the clearance of glucose and ROS. Furthermore, the MCPtA was encapsulated within a glucose-responsive hydrogel cross-linked via a borate ester bond, termed PAM, to evaluate the potential of the composite hydrogel for cranial defect repair in diabetic rats. The in vitro/vivo experiments as well as the RNA sequencing analysis demonstrated that the nanoenzyme composite hydrogel could disrupt the glucose-ROS-induced inflammation and promoted osteogenesis and angiogenesis, in consequence, improving the therapeutic effects for diabetic bone regeneration. This study provided crucial insights into nanoenzyme-mediated microenvironmental regulation for diabetic bone regeneration.
Surface S-Doped Nanostructured RuO2 and Its Anion Passivating Effect for Efficient Overall Seawater Splitting
Yu Liu - ,
Lu Wu - ,
Yong Wang - ,
Le-Wei Shen - ,
Ge Tian *- ,
Lianmeng Cui - ,
Ling Qin - ,
Liang Zhou - ,
Yuexing Zhang *- ,
Federico Rosei - , and
Xiao-Yu Yang *
Electrolysis of seawater for hydrogen (H2) production to harvest clean energy is an appealing approach. In this context, there is an urgent need for catalysts with high activity and durability. RuO2 electrocatalysts have shown efficient activity in the hydrogen and oxygen evolution reactions (HER and OER), but they still suffer from poor stability. Herein, surface S-doped nanostructured RuO2 (S-RuO2) is rationally fabricated for efficient overall seawater splitting. Doping with S enhances the activity (overpotentials of 25 mV for the HER and 243 mV for the OER), long-term durability (1000 h at 100 mA cm–2), and achieves nearly 100% Faraday efficiency (FE). Moreover, the S-RuO2-based anion exchange membrane seawater electrolyzer requires 2.01 V to reach 1.0 A cm–2 under demanding industrial conditions. Experimental analysis and theoretical calculations indicate that surface S introduction could lower the valence state of Ru, thereby conferring enhanced activity and stability. Furthermore, the nanostructured S-RuO2 electrocatalyst is highly protected by the S-doped surface, which repels Cl– in alkaline seawater. This investigation presents a feasible strategy for designing RuO2-based seawater splitting catalysts with both high performance and good resistance to anodic corrosion.
MicroSphere 3D Structures Delay Tissue Senescence through Mechanotransduction
Ziang Li - ,
Jincheng Tang - ,
Liang Zhou - ,
Jiannan Mao - ,
Wei Wang - ,
Ziyan Huang - ,
Lichen Zhang - ,
Jie Wu - ,
Xinzhao Jiang - ,
Zhouye Ding - ,
Kun Xi *- ,
Feng Cai *- ,
Yong Gu *- , and
Liang Chen *
The extracellular matrix (ECM) stores signaling molecules and facilitates mechanical and biochemical signaling in cells. However, the influence of biomimetic “rejuvenation” ECM structures on aging- and degeneration-related cellular activities and tissue repair is not well understood. We combined physical extrusion and precise “on–off” alternating cross-linking methods to create anisotropic biomaterial microgels (MicroRod and MicroSphere) and explored how they regulate the cell activities of the nucleus pulposus (NP) and their potential antidegenerative effects on intervertebral discs. NP cells exhibited aligned growth along the surface of the MicroRod, enhanced proliferation, and reduced apoptosis. This suggests an adaptive cellular response involving adhesion and mechanosensing, which causes cytoskeletal extension via environmental cues. NP cells maintain nuclear membrane integrity through the YAP/TAZ pathway, which activates the cGAS-STING pathway to rectify the aging mechanisms. In vivo, MicroRod carries NP cells and reduces inflammatory factor and protease secretion in degenerated intervertebral discs, inhibiting degeneration and promoting NP tissue regeneration. Our findings highlight the role of mechanical stress in maintaining cellular activity and antiaging effects in harsh environments, providing a foundation for further research and development of antidegenerative biomaterials.
Flexible Morphological Regulation of Photothermal Nanodrugs: Understanding the Relationship between the Structure, Photothermal Effect, and Tumoral Biodistribution
Shukun Li - ,
Yudong Li - ,
Guizhi Shen - ,
Juping Sun - ,
Loai K. E. A. Abdelmohsen - ,
Xuehai Yan *- , and
Jan C. M. van Hest *
This publication is Open Access under the license indicated. Learn More
The morphology of nanodrugs is of utmost importance in photothermal therapy because it directly influences their physicochemical behavior and biological responses. However, clarifying the inherent relationship between morphology and the resultant properties remains challenging, mainly due to the limitations in the flexible morphological regulation of nanodrugs. Herein, we created a range of morphologically controlled nanoassemblies based on poly(ethylene glycol)-block-poly(d,l-lactide) (PEG–PLA) block copolymer building blocks, in which the model photosensitizer phthalocyanine was incorporated. Four different topologies were compared, namely, spherical vesicles, bowl-shaped vesicles, rodlike micelles, and vesicular tubes. The photothermal properties and in vivo tumoral biodistribution were investigated, revealing their relationship with the particle morphology. Finally, the tumor ablation capability of the optimized nanodrugs was demonstrated. This study represents a systematic study of the morphologically discrete regulation of nanodrugs, highlighting the importance of customization of supramolecular photothermal nanodrugs toward clinical antitumor therapy.
Shell Dependence of Highly Tunable Circular Dichroism in Chiral Hybrid Plasmonic Nanomaterials for Chiroptical Applications
Guizeng Yang - ,
Yunlong Tao - ,
Qingqing Cheng - ,
Chuang Liu - ,
Binbin Zhang - ,
Xuehao Sun - ,
Yahui Yang - ,
Dandan Lu - ,
Jian Yang - ,
Lin-Long Deng - ,
Lichao Sun *- ,
Hongxing Xu - ,
Su-Yuan Xie - , and
Qingfeng Zhang *
Chiral plasmonic nanomaterials with fascinating physical and chemical properties show emerging chirality-dependent applications in photonics, catalysis, and sensing. The capability to precisely manipulate the plasmonic chirality in a broad spectral range plays a crucial role in enabling the applications of chiral nanomaterials in diverse and complex scenarios; however, it remains a challenge yet to be addressed. Here we demonstrate a strategy to significantly enhance the tunability of circular dichroism (CD) spectra of chiral nanomaterials by constructing core–shell hybrid metal–semiconductor structures with tailored shells. In a typical case, chiral Au@Cu2O nanostructures exhibit shell-dependent tunable CD signals in both asymmetry factors and band wavelengths. The shell-dependent CD was demonstrated experimentally by CD and single-particle spectroscopy and theoretically through numerical simulations. By deliberately controlling the geometry of the chiral core and the composition of the achiral shell, we show the versatility of our strategy for constructing chiral hybrid nanostructures with increasing architectural and compositional complexity as well as enhanced plasmonic chirality. Furthermore, the chiral Au@Cu2O nanostructure exhibits intriguing asymmetric color modulation. This work opens an advancing strategy and provides an important knowledge framework for the rational design of multifunctional chiral hybrid nanostructures toward emerging chirality-dependent applications.
Correction to “Integrating Vascular Phenotypic and Proteomic Analysis in Open Microfluidic Platform”
Sangmin Jung - ,
Sunghun Cheong - ,
Yoonho Lee - ,
Jungseub Lee - ,
Jihye Lee - ,
Min-Seok Kwon - ,
Young Sun Oh - ,
Taewan Kim - ,
Sungjae Ha - ,
Sung Jae Kim - ,
Dong Hyun Jo - ,
Jihoon Ko - , and
Noo Li Jeon *
This publication is Open Access under the license indicated. Learn More
January 8, 2025
Pseudomorphic Transformation in Nanostructured Thiophene-Based Materials
Mattia Zangoli - ,
Raffaello Mazzaro - ,
Eugenio Lunedei - ,
Eduardo Fabiano - ,
Ilse Manet - ,
Andrea Candini - ,
Alessandro Kovtun - ,
Meriem Goudjil - ,
Alberto Zanelli - ,
Shlomo Rozen - ,
Massimo Gazzano - ,
Massimo Baroncini *- , and
Francesca Di Maria *
This study reveals the capability of nanostructured organic materials to undergo pseudomorphic transformations, a ubiquitous phenomenon occurring in the mineral kingdom that involves the replacement of a mineral phase with a new one while retaining the original shape and volume. Specifically, it is demonstrated that the postoxidation process induced by HOF·CH3CN on preformed thiophene-based 1D nanostructures preserves their macro/microscopic morphology while remarkably altering their electro-optical properties by forming a new oxygenated phase. Experimental evidence proves that this transformation proceeds via an interface-coupled dissolution–precipitation mechanism, leading to the growth of a porous oxidized shell that varies in thickness with exposure time, enveloping the pristine smooth core. The oxygenated species exhibits stronger electron-acceptor characteristics than the core material, promoting charge transfer state formation, as confirmed by microspectroscopy and DFT calculations. This enables (i) precise modulation of the nanostructure’s surface potential, allowing for the formation of entirely organic heterojunctions with precise spatial resolution via wet chemical processing; (ii) effective doping of the nanostructure, resulting in a strong change of the conductivity temperature dependence and a switch between a low and high conduction state depending on the applied bias. Overall, this work showcases an approach to engineering “impossible” composite architectures with pre-established morphology and tailored chemical-physical properties.
AI-Based Prediction of Protein Corona Composition on DNA Nanostructures
Jared Huzar - ,
Roxana Coreas - ,
Markita P. Landry - , and
Grigory Tikhomirov *
This publication is Open Access under the license indicated. Learn More
DNA nanotechnology has emerged as a powerful approach to engineering biophysical tools, therapeutics, and diagnostics because it enables the construction of designer nanoscale structures with high programmability. Based on DNA base pairing rules, nanostructure size, shape, surface functionality, and structural reconfiguration can be programmed with a degree of spatial, temporal, and energetic precision that is difficult to achieve with other methods. However, the properties and structure of DNA constructs are greatly altered in vivo due to spontaneous protein adsorption from biofluids. These adsorbed proteins, referred to as the protein corona, remain challenging to control or predict, and subsequently, their functionality and fate in vivo are difficult to engineer. To address these challenges, we prepared a library of diverse DNA nanostructures and investigated the relationship between their design features and the composition of their protein corona. We identified protein characteristics important for their adsorption to DNA nanostructures and developed a machine-learning model that predicts which proteins will be enriched on a DNA nanostructure based on the DNA structures’ design features and protein properties. Our work will help to understand and program the function of DNA nanostructures in vivo for biophysical and biomedical applications.
Toward Resolving Heterogeneous Mixtures of Nanocarriers in Drug Delivery Systems through Light Scattering and Machine Learning
Allan Mancoo - ,
Mariana Silva - ,
Claudia Lopes - ,
Maria Loureiro - ,
Vanessa Pinto - ,
João F. C. B. Ramalho - ,
Patricia Carvalho - ,
Carlos A. J. Gouveia - ,
Sara Rocha - ,
Sandro M. P. Bordeira - ,
Paula M. Sampaio - ,
Alex Turpin - ,
Henkjan Gersen - , and
Mehak Mumtaz *
Nanocarriers (NCs) have emerged as a revolutionary approach in targeted drug delivery, promising to enhance drug efficacy and reduce toxicity through precise targeting and controlled release mechanisms. Despite their potential, the clinical adoption of NCs is hindered by challenges in their physicochemical characterization, essential for ensuring drug safety, efficacy, and quality control. Traditional characterization methods, such as dynamic light scattering and nanoparticle tracking analysis, offer limited insights, primarily focusing on particle size and concentration, while techniques like high-performance liquid chromatography and mass spectrometry are hampered by extensive sample preparation, high costs, and potential sample degradation. Addressing these limitations, this work presents a cost-effective methodology leveraging light scattering and optical forces, combined with machine learning algorithms, to characterize polydisperse nanoparticle mixtures, including lipid-based NCs. We prove that our approach provides quantification of the relative concentration of complex nanoparticle suspensions by detecting changes in refractive index and polydispersity without extensive sample preparation or destruction, offering a high-throughput solution for NC characterization in drug delivery systems. Experimental validation demonstrates the method’s efficacy in characterizing commercially available synthetic nanoparticles and Doxoves, a liposomal formulation of Doxorubicin used in cancer treatment, marking a significant advancement toward reliable, noninvasive characterization techniques that can accelerate the clinical translation of nanocarrier-based therapeutics.
Operando Gravimetric and Energy Loss Analysis of Na3V2(PO4)2F3 Composite Films by Electrochemical Quartz Microbalance with Dissipation Monitoring
Jeronimo Miranda - ,
Pierre-Louis Taberna *- , and
Patrice Simon *
The rising demand for energy storage calls for technological advancements to address the growing needs. In this context, sodium-ion (Na-ion) batteries have emerged as a potential complementary technology to lithium-ion batteries (Li-ion). Among other materials, Na3V2(PO4)2F3 (NVPF) is a promising cathode for Na-ion batteries due to its high operating voltage and good energy density. In order to further characterize the (dis)charge behavior of NVPF, the electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D) was employed to track both the frequency and dissipation loss changes at the electrode/electrolyte interface. The electrode composite preparation proved to be crucial for extending the potential window to both Na3V2(PO4)2F3/Na2V2(PO4)2F3 and Na2V2(PO4)2F3/Na1V2(PO4)2F3 domains. Composites prepared with rawNVPF powder (1–20 μm particles) and polyvinylidene fluoride (PVDF) binder (raw-NVPF:PVDF) exhibited large dissipation changes during (dis)charging, attributed to the soft viscoelastic nature of the binder and substantial hydrodynamic interaction caused by the large particles. On the other hand, composites prepared by sieved NVPF particles (<1 μm particles) with sodium carboxymethyl cellulose (NaCMC) binder (sieved-NVPF:NaCMC) showed rigid properties, enabling an extended and more accurate gravimetric analysis. This allowed for the determination of a linear charge-to-mass relationship for the full potential window of NVPF, reflecting the potential independent insertion/deinsertion of bare Na ions (23 g·mol–1). Additionally, reversible dissipative changes were observed for the Na3V2(PO4)2F3/Na2V2(PO4)2F3 transition, with no further dissipative changes observed during the Na2V2(PO4)2F3/Na1V2(PO4)2F3 process.
Complexity in the Photofunctionalization of Single-Wall Carbon Nanotubes with Hypochlorite
Vanessa B. Espinoza - ,
Sergei M. Bachilo - ,
Yu Zheng - ,
Han Htoon - , and
R. Bruce Weisman *
The reaction of aqueous suspensions of single-wall carbon nanotubes (SWCNTs) with UV-excited sodium hypochlorite has previously been reported to be an efficient route for doping nanotubes with oxygen atoms. We have investigated how this reaction system is affected by pH level, dissolved O2 content, and radical scavengers and traps. Products were characterized with near-IR fluorescence, Raman, and XPS spectroscopy. The reaction is greatly accelerated by removal of dissolved O2 and strongly suppressed by TEMPO, a radical trap. Alcohols added as radical scavengers alter the reaction efficiency and the product peak emission wavelengths. Photofunctionalization with 300 nm irradiation is substantially less efficient at pH levels low enough to protonate the OCl– ion to HOCl. We deduce that in mildly treated high pH samples, the main product is sp2 hybridized O-doped adducts formed by reaction of SWCNTs with atomic oxygen in its 3P (ground) level. By contrast, treatment under low pH conditions leads to sp3 hybridized SWCNT adducts formed by the addition of secondary radicals from reactions of •OH and •Cl. There is also evidence for additional photoreactions of product species under stronger irradiation. Researchers using photoexcited hypochlorite for SWCNT functionalization should be alert to the range of products and the sensitivity to reaction conditions in this system.
Long-Range Metal–Sorbent Interactions Determine CO2 Capture and Conversion in Dual-Function Materials
Shradha Sapru - ,
Kelle D. Hart - ,
Chengshuang Zhou - ,
Gennaro Liccardo - ,
Jinwon Oh - ,
Margaret J. Hollobaugh - ,
Jorge Osio-Norgaard - ,
Arun Majumdar - ,
Bert D. Chandler - , and
Matteo Cargnello *
Carbon capture and utilization involve multiple energy- and cost-intensive steps. Dual-function materials (DFMs) can reduce these demands by coupling CO2 adsorption and conversion into a single material with two functionalities: a sorbent phase and a metal for catalytic CO2 conversion. The role of metal catalysts in the conversion process seems salient from previous work, but the underlying mechanisms remain elusive and deserve deeper investigation to achieve maximum utilization of the two phases. Here, preformed colloidal Ru nanoparticles were deposited onto a “NaOx”/Al2O3 sorbent to prepare prototypical DFMs with controlled phases for CO2 capture and hydrogenation to CH4. Ru addition was found to double the high-temperature CO2 adsorption capacity by activating the “NaOx”/Al2O3 sorbent phase during a reductive pretreatment step. Most importantly, low Ru loadings were sufficient to ensure maximum CO2 adsorption and conversion. This was attributed to the key role of the metal–sorbent interactions, wherein Ru was required to hydrogenate strongly bound CO2 on the “NaOx”/Al2O3 sorbent to CH4 via the H2 activated on Ru. This interaction facilitated rate-determining carbonate migration and subsequent hydrogenation at the metal–sorbent interface. Overall, Ru controlled the CO2 hydrogenation reaction rate, while the “NaOx”/Al2O3 sorbent dictated the CO2 uptake capacity. By controlling metal–sorbent interactions at the molecular level, we demonstrate the critical role of the two phases and their synergy, facilitating the design of DFMs with maximum CO2 capture and conversion efficiency.
Overscreening-Driven Modulation of Ion Adsorption and Desorption in Conductive MOF Electrodes by Charging Rates
Liang Niu - ,
Liang Zeng - ,
Ding Yu - ,
Situo Cheng - , and
Guang Feng *
Elucidating the charging mechanism plays an intrinsic and critical role in the development of high-performance supercapacitors; however, a deep understanding of how this mechanism varies under different charging rates remains challenging. In this study, we investigate the charging mechanism of conductive metal–organic framework (c-MOF) electrodes in ionic liquids, combining electrochemical quartz crystal microbalance and constant-potential molecular dynamics simulations. Both experimental and modeling results reveal a transition of the ion adsorption and desorption modes from anion dominance at low charging rates to ion-exchange governance at high charging rates, significantly reducing the contribution of anions to the capacitance. The dynamic structures of in-pore ions suggest that this transition stems from variations in the overscreening strength, which leads to different ion responses between the central and surface regions of c-MOF pores under polarization. This work could lay the foundation for optimizing supercapacitor design, especially under high charging rates.
Unlocking Sulfide Solid-State Battery Longevity by the Paradigm of Dual-Functional Plastic Crystal
Haoyang Yuan - ,
Wenjun Lin - ,
Shaojie Chen - ,
Changhao Tian - ,
Tao Huang *- , and
Aishui Yu *
The utilization of sulfide-based solid electrolytes represents an attractive avenue for high safety and energy density all-solid-state batteries. However, the potential has been impeded by electrochemical and mechanical stability at the interface of oxide cathodes. Plastic crystals, a class of organic materials exhibiting remarkable elasticity, chemical stability, and ionic conductivity, have previously been underutilized due to their susceptibility to dissolution in liquid electrolytes. Nevertheless, their application in all-solid-state batteries presents a paradigm that could potentially overcome longstanding interface-related obstacles. This study presents a facile approach to enhancing the performance of sulfide-based solid-state batteries by utilizing nickel-rich oxide cathodes coated with ionically conductive plastic crystals. For employing plastically deformed succinonitrile as a metal ion ligand, it simultaneously supports mechanical stability and interfacial conduction, while LiDFOB establishes moderate ionic conductivity and a stable cathode electrolyte interphase (CEI). The synergistic effects of these mechanisms culminate in remarkable long-term performance metrics, with the capacity retaining 80% after 1529 cycles. Furthermore, this stability is maintained even when the areal capacity density is increased to a substantial 3.53 mA h cm–2. By combining electrochemical stability with mechanical plasticity, this approach opens possibilities for the development of long-lasting solid-state batteries suitable for practical applications.
HCP-to-FCC Phase Transformation of Ruthenium Nanocrystals Selectively Activate Hydrogen Peroxide for Boosting Peroxidase-like Activity
Xilin Ding - ,
Jin Liu - ,
Hongxiang Chen - ,
Yu Zhou - ,
Chengzhou Zhu - , and
Hongye Yan *
Due to the simultaneous activation of hydrogen peroxide (H2O2) and oxygen, Ru nanocrystals exhibit inherent peroxidase- and oxidase-like activities, thereby limiting their extensive application in biosensing. Phase engineering of Ru nanocrystals holds great promise for enhancing catalytic activity and selectivity but remains a challenge. Here, highly active Ru nanocrystals with a metastable face-centered cubic (fcc) structure were successfully synthesized via a facile wet-chemical method followed by an etching step, enabling selective activation of H2O2 and demonstrating promising peroxidase-like activity. Compared to the thermodynamically favored hexagonal close-packed Ru nanocrystals, the resultant fcc Ru shows an over 5-fold enhancement in the maximum reaction velocity of the peroxidase-like catalysis, while its oxidase-like performance exhibits a minor decline, indicating a transition from multienzyme activity to specificity. Theoretical calculations reveal that the phase transformation of Ru not only results in an upward shift of the d-band center to enhance H2O2 adsorption but also regulates the O–O bonding strength of H2O2 to achieve selective H2O2 activation. As a proof of concept, a colorimetric sensor based on fcc Ru nanocrystals was successfully constructed, achieving accurate and sensitive detection of organophosphorus pesticides. This work not only offers promising prospects for phase engineering of Ru nanocrystals but also highlights the significance of the Ru phase transition in hydrogen peroxide activation.
Distance and Voltage Dependence of Orbital Density Imaging Using a CO-Functionalized Tip in Scanning Tunneling Microscopy
Fabian Paschke - ,
Leonard-Alexander Lieske - ,
Florian Albrecht - ,
C. Julian Chen - ,
Jascha Repp - , and
Leo Gross *
This publication is Open Access under the license indicated. Learn More
The appearance of frontier molecular ion resonances measured with scanning tunneling microscopy (STM)─often referred to as orbital density images─of single molecules was investigated using a CO-functionalized tip in dependence on bias voltage and tip–sample distance. As model systems, we studied pentacene and naphthalocyanine on bilayer NaCl on Cu(111). Absolute tip–sample distances were determined by means of atomic force microscopy (AFM). STM imaging revealed a transition from predominant p- to s-wave tip contrast upon increasing the tip–sample distance, but the contrast showed only small changes as a function of voltage. The distance-dependent contrast change is explained with the steeper decay of the tunneling matrix element for tunneling between two p-wave centers, compared to tunneling between two s-wave centers. In simulations with a fixed ratio of s- to p-wave tip states, we can reproduce the experimental data including the distance-dependent transition from predominant p- to s-wave tunneling contribution.
Surface-Enhanced Raman Spectroscopy for the Detection of Reactive Oxygen Species
Dongchang Yang - ,
Brian Youden - ,
Naizhen Yu - ,
Andrew J. Carrier - ,
Runqing Jiang *- ,
Mark R. Servos - ,
Ken D. Oakes - , and
Xu Zhang *
Reactive oxygen species (ROS) play fundamental roles in various biological and chemical processes in nature and industries, including cell signaling, disease development and aging, immune defenses, environmental remediation, pharmaceutical syntheses, metal corrosion, energy production, etc. As such, their detection is of paramount importance, but their accurate identification and quantification are technically challenging due to their transient nature with short lifetimes and low steady-state concentrations. As a highly sensitive and selective analytical technique, surface-enhanced Raman spectroscopy (SERS) is promising for detecting ROS in real-time, enabling in situ monitoring of ROS-involved electrochemical and biochemical events with exceptional resolution. This review provides a comprehensive analysis of the state-of-the-art in the SERS-based detection of ROS. Herein, the principles and ROS sensing mechanisms of SERS have been critically evaluated, highlighting their emerging applications in direct and indirect ROS monitoring in electrochemical and biological systems. The developments and reaction schemes of selective SERS probes for superoxide (•O2–), hydroxyl radicals (•OH), nitric oxide (•NO), peroxynitrite (ONOO–), and hypochlorite (OCl–) are presented. Finally, technical challenges and future research directions are discussed to guide the design of SERS for ROS analysis.
Local Symmetry-Broken Single Pd Atoms Induced by Doping Ag Sites for Selective Electrocatalytic Semihydrogenation of Alkynes
Xiuling Guo - ,
Chao Feng - ,
Zihao Yang - ,
Shingo Hasegawa - ,
Ken Motokura - , and
Yong Yang *
Engineering the local coordination environment of single metal atoms is an effective strategy to improve their catalytic activity, selectivity, and stability. In this study, we develop an asymmetric Pd–Ag diatomic site on the surface of g-C3N4 for the selective electrocatalytic semihydrogenation of alkynes. The single Pd atom catalyst, which has a locally symmetric Pd coordination, was inactive for the semihydrogenation of phenylacetylene in a 1 M KOH and 1,4-dioxane solution at an applied potential of −1.3 V (vs RHE). In sharp contrast, doping Ag sites into single Pd atom catalyst to form paired Pd–Ag diatomic sites with asymmetric Pd coordination substantially enhanced the reaction, resulting in a high conversion (>98%) with exceptional time-independent selectivity to styrene under identical conditions. Characterization and theoretical calculations reveal that the introduction of a Ag site into single Pd atoms disrupts their symmetry coordination by forming Pd–Ag bonds with N2–Pd–Ag–N configuration, thereby modulating the electronic and geometric structures of Pd sites, which in turn benefits the adsorption and activation of substrate and lowers energy barrier for the rate-determining step of semihydrogenation, ultimately enhancing the electrocatalytic reaction. This work provides a facile and powerful strategy for the design of advanced catalysts by tuning the local coordination environment for selective catalysis.
Living Cell-Mediated Self-Assembly: From Monomer Design and Morphology Regulation to Biomedical Applications
Chengfei Liu - ,
Haonan Ma - ,
Shengzhuo Yuan - ,
Yifan Jin - , and
Wei Tian *
The self-assembly of molecules into highly ordered architectures is a ubiquitous and natural process, wherein molecules spontaneously organize into large structures to perform diverse functions. Drawing inspiration from the formation of natural nanostructures, cell-mediated self-assembly has been developed to create functional assemblies both inside and outside living cells. These techniques have been employed to regulate the cellular world by leveraging the dynamic intracellular and extracellular microenvironment. This review highlights the recent advances and future trends in living cell-mediated self-assembly, ranging from their cytocompatible monomer designs, synthetic strategies, and morphological control to functional applications. The assembly behaviors are also discussed based on the dimensionality of the self-assembled morphologies from zero to three dimensions. Finally, this review explores its promising potential for biomedical applications, clarifying the relationship between initial morphological regulation and the therapeutic effects of subsequent artificial assemblies. Through rationally designing molecular structures and precisely controlling assembly morphologies, living cell mediated self-assembly would provide an innovative platform for executing biological functions.
Highly Reversible Anode-Free Lithium Metal Batteries Enabled by Porous Organic Cages with Subnano Lithiophilic Triangular Windows
Jipeng Xu - ,
Kai Qu - ,
Xinrui Li - ,
Yan Cui - ,
Jingkun Li *- ,
Honglai Liu - , and
Cheng Lian *
The widespread application of anode-free lithium metal batteries (AFLMBs) is hindered by the severe dendrite growth and side reactions due to the poor reversibility of Li plating/stripping. Herein, our study introduces an ultrathin interphase layer of covalent cage 3 (CC3) for highly reversible AFLMBs. The subnano triangular windows in CC3 serve as a Li+ sieve to accelerate Li+ desolvation and transport kinetics, inhibit electrolyte decomposition, and form LiF- and Li3N-rich solid-electrolyte interphases. Moreover, the lithiophilic backbone of CC3 homogenizes Li+ distribution and deposition with mitigated dendrite growth. Thus, CC3 promotes Li plating/stripping kinetics and reversibility, achieving an ultralong stability over 8000 h of the Cu@CC3 electrode. Furthermore, practical Cu@CC3/LiFePO4 AFLMBs deliver a capacity retention (66%) over 600 cycles. This work emphasizes the effectiveness of CC3 to regulate the Li plating/stripping behavior, demonstrating the application potential of porous organic cages for enhancing the cycle life of AFLMBs.
Microemulsion-Inspired Polysaccharide Nanoparticles for an Advanced Targeted Thrombolytic Treatment
Thibault de La Taille - ,
Pierre Sarfati - ,
Rachida Aid - ,
Louise Fournier - ,
Graciela Pavon-Djavid - ,
Frédéric Chaubet - , and
Cédric Chauvierre *
Among cardiovascular diseases, thrombotic diseases such as ischemic heart disease and acute ischemic strokes are the most lethal, responsible by themselves for a quarter of worldwide deaths. While surgical treatments exist, they may not be used in all situations, and systemic thrombolytic drug injection, such as recombinant tissue plasminogen activators (rtPA), often remains necessary, despite serious limitations including short therapeutic window, severe side effects, and failure to address the complex nature of thrombi. This prompted intense research into alternative thrombolytics or delivery methods, including nanomedicine. However, most nanoparticles face issues of stability, biocompatibility, or synthesis robustness; among them, polymeric nanoparticles, though usually versatile and biocompatible, sometimes lack robustness and may involve toxic or complex synthesis. Here, we present polysaccharide hydrogel nanoparticles designed with an improved microemulsion-based approach that allowed a critical size reduction from microparticles to 315 nm nanoparticles. They were decorated with fucoidan, a sulfated polysaccharide capable of high affinity binding to P-selectin, a thrombi biomarker. These nanoparticles exhibited good stability, adequate size, biocompatibility, and targeting capacity and could be loaded with two different drugs, rtPA (fibrin degradation) or DNase I (degradation of neutrophil extracellular traps, or NETs), to exert thrombolysis. Notably, improved synergic thrombolysis was demonstrated on NET-containing thrombi, while in vivo thrombolysis shed light into improved thrombolysis of rtPA-loaded nanoparticles at 50 and 10% the recommended dose without secondary embolization. These safe, robust, and easy-to-make nanoparticles could provide effective delivery strategies for thrombolytic treatments while demonstrating the potential of polysaccharide nanoparticles as drug-delivery agents.
January 7, 2025
Inhalable Mucociliary-On-Chip System Revealing Pulmonary Clearance Dynamics in Nanodrug Delivery
Ko-Chih Lin - ,
Hsuan-Yu Lin - ,
Chuan-Yi Yang - ,
Ying-Ling Chu - ,
Ren-Hao Xie - ,
Cheng-Ming Wang - ,
Yun-Long Tseng - ,
He−Ru Chen - ,
Johnson H. Y. Chung - ,
Jia-Wei Yang *- , and
Guan-Yu Chen *
This publication is Open Access under the license indicated. Learn More
The development of a inhaled nanodrug delivery assessment platform is crucial for advancing treatments for chronic lung diseases. Traditional in vitro models and commercial aerosol systems fail to accurately simulate the complex human respiratory patterns and mucosal barriers. To address this, we have developed the breathing mucociliary-on-a-chip (BMC) platform, which replicates mucociliary clearance and respiratory dynamics in vitro. This platform allows for precise analysis of drug deposition and penetration, providing critical insights into how liposomes and other nanocarriers interact with lung tissues under various airflow conditions. Our results reveal that liposomes penetrate deeper into the cellular layer under high shear stress, with both static and dynamic airflows distinctly affecting their drug release rates. The BMC platform integrates dynamic inhalation systems with mucociliary clearance functionality, enabling a comprehensive evaluation of drug delivery efficacy. This approach highlights the importance of airflow dynamics in optimizing inhalable nanodrug delivery systems, improving nanocarrier design, and tailoring drug dosages and release strategies. The BMC platform represents a significant advancement in the field of inhaled nanodrug delivery, offering a more accurate and reliable method for assessing the performance of therapies. By providing a detailed understanding of drug interactions with lung tissues, this platform supports the development of personalized inhaled therapies and offers promising strategies for treating pulmonary diseases and advancing nanodrug development.
Drug in Drug: Quorum Sensing Inhibitor in Star-Shaped Antibacterial Polypeptides for Inhibiting and Eradicating Corneal Bacterial Biofilms
Zhouyu Lu - ,
Wenjie Fan - ,
Yang Ye - ,
Yue Huang - ,
Xianchi Zhou - ,
Yin Zhang - ,
Wenyu Cui - ,
Jian Ji *- ,
Ke Yao *- , and
Haijie Han *
Biofilm-related bacterial keratitis is a severe ocular infection that can result in drastic vision impairment and even blindness. However, the therapeutic efficiency of clinical antibiotic eyedrops is often compromised because the bacteria in the biofilms resist bactericide via the community genetic regulation, namely, bacterial quorum sensing. Herein, quercetin (QCT)-loaded star-shaped antibacterial peptide polymer (SAPP), QCT@SAPP, is developed based on a “drug” in a “drug” strategy for inhibiting and eradicating Pseudomonas aeruginosa biofilms on the cornea. The natural antibacterial peptide-mimic SAPP with the positively charged amphipathic structure not only enables QCT@SAPP to penetrate the biofilms readily but also selectively adheres to the highly negatively charged P. aeruginosa, releasing the loaded QCT into the bacteria to regulate quorum sensing by inhibiting lasI, lasR, rhlR, and rhlI. Thanks to its robust bactericidal ability from SAPP, QCT@SAPP can eliminate more than 99.99% of biofilms. Additionally, QCT@SAPP displayed outstanding performance in relieving ocular inflammation by significantly downregulating pro-inflammatory cytokines and profiting from scavenging reactive oxygen species by releasing QCT, which finally helps to restore visual function. In conclusion, QCT@SAPP, with good compatibility, exerts excellent therapeutic effects in a bacterial keratitis mice model, making it a promising candidate for controlling bacterial biofilm-induced infections, including bacterial keratitis.
DNA Self-Assembly Generated by Aptamer-Triggered Rolling Circle Amplification Cascades for Profiling Colorectal Cancer-Derived Small Extracellular Vesicles
Yawei Feng - ,
Yunshan Yang - ,
Pei Guo - ,
Lizhuan Zhang - ,
Yunben Yang - ,
Zeyin Zhao - ,
Cheng Cui - ,
Qiuxia Yang - ,
Yong Liu - ,
Liu Yang *- ,
Ruizi Peng *- , and
Weihong Tan *
The analysis of small extracellular vesicles (sEVs) has shown clinical significance in early cancer diagnostics and considerable potential in prognostic assessment and therapeutic monitoring, offering possibilities for precise clinical intervention. Despite recent diagnostic progress based on blood-derived sEVs, the inability to specifically profile multiple parameters of sEVs proteins has hampered advancement in clinical applications. Herein, we report an approach to profile colorectal cancer (CRC)-derived sEVs by using multiaptamer-triggered rolling circle amplification (RCA) cascades. In practice, in the presence of target sEVs, the complementary strands are released from the duplexes of the structure-switching aptamer. Then, the RCA cascade occurs but only when the specific DNA strand pair is presented. As a result, the noncanonical DNA assemblies are generated whose size reaches micrometers that can be directly analyzed by conventional flow cytometry, thereby facilitating facile clinical diagnostics. In this study, the developed diagnostic method is verified on cell-derived sEVs, followed by achieving modeling based on clinical samples. The final diagnostic results from the clinical cohort indicate promising diagnostic efficacy for CRC-derived sEVs with 92% sensitivity, 86.7% specificity, and 90% overall accuracy, highlighting the substantial potential of sEVs as biomarkers for CRC diagnosis and significantly advancing the development of clinical tools for early disease diagnosis.
Structure–Stability Relationships in Pt-Alloy Nanoparticles Using Identical-Location Four-Dimensional Scanning Transmission Electron Microscopy and Unsupervised Machine Learning
Ana Rebeka Kamšek *- ,
Francisco Ruiz-Zepeda - ,
Marjan Bele - ,
Anja Logar - ,
Goran Dražić - , and
Nejc Hodnik *
This publication is Open Access under the license indicated. Learn More
Nanoparticulate electrocatalysts for the oxygen reduction reaction are structurally diverse materials. Scanning transmission electron microscopy (STEM) has long been the go-to tool to obtain high-quality information about their nanoscale structure. More recently, its four-dimensional modality has emerged as a tool for a comprehensive crystal structure analysis using large data sets of diffraction patterns. In this study, we track the alternations of the crystal structure of individual carbon-supported PtCu3 nanoparticles before and after fuel cell-relevant activation treatment, consisting of a mild acid-washing protocol and potential cycling, essential for forming an active catalyst. To take full advantage of the rich, identical location 4D-STEM capabilities, unsupervised algorithms were used for the complex data analysis, starting with k-means clustering followed by non-negative matrix factorization, to find commonly occurring signals within specific nanoparticle data. The study revealed domains with (partially) ordered alloy structures, twin boundaries, and local amorphization. After activation, specific nanoparticle surface sites exhibited a loss of crystallinity which can be correlated to the simultaneous local scarcity of the ordered alloy phase, confirming the enhanced stability of the ordered alloy during potential cycling activation conditions. With the capabilities of our in-house developed identical-location 4D-STEM approach to track changes in individual nanoparticles, combined with advanced data analysis, we determine how activation treatment affects the electrocatalysts’ local crystal structure. Such an approach provides considerably richer insights and is much more sensitive to minor changes than traditional STEM imaging. This workflow requires little manual input, has a reasonable computational complexity, and is transferrable to other functional nanomaterials.
K+-Responsive Nanoparticles with Charge Reversal and Gating Synergistic Effects for Targeted Intracellular Bacteria Eradication
Jue-Ying Gong - ,
Yao Li - ,
Po Wang - ,
Xu Peng - ,
Rui Xie - ,
Wei Wang - ,
Zhuang Liu - ,
Da-Wei Pan - ,
Xiao-Jie Ju *- , and
Liang-Yin Chu
Intracellular bacteria can evade the attack of the immune system and the bactericidal effects of most antibiotics due to the protective effect of the host cells. Herein, inspired by the stimuli-responsive behaviors of biological ion channels, a kind of synergistic cascade potassium ion (K+)-responsive nanoparticles gated with K+-responsive polymers is ingeniously designed to target intracellular bacteria and then control drug release. Due to the cooperative interaction of host–guest complexation and conformational transition of K+-responsive polymers, the grafted gates based on these polymers could recognize high K+ concentration to reverse the negatively charged nanoparticles into positively charged ones for targeting bacteria and subsequently inducing a switch from the hydrophobic shrinking “off” state to the hydrophilic stretching “on” state for drug release. The K+-responsive nanoparticles can effectively load antibiotics and be endocytosed into the infected cells, and K+-responsive gates can be actuated by a high intracellular K+ concentration. With the efficient synergistic cascade strategy, these K+-responsive nanocarriers can deliver antibiotics to the subcellular region where intracellular bacteria reside and show superior elimination efficiencies in vitro and in vivo than the free drug in delivering vancomycin. The K+-responsive nanocarriers are expected to improve the bioavailability of drugs and enhance their antibacterial efficacy.
Nanotwin-Induced Ferrimagnetism in an Antiferromagnetic Cr2O3 Thin Film on the SrTiO3 Substrate
Xiang Li - ,
Yixiao Jiang - ,
Min Tian - ,
Ting Xiong - ,
Tingting Yao *- ,
Xuexi Yan - ,
Ang Tao - ,
Zhiqing Yang - ,
Hengqiang Ye - ,
Xiu-Liang Ma - , and
Chunlin Chen *
Nanotwinned materials have recently attracted intense interest since they often exhibit excellent mechanical properties that are far superior to those of the corresponding single crystals. However, how nanotwinned structures affect the physical properties of functional materials remains almost unexplored. In this study, we demonstrate ferrimagnetism in a nanotwinned antiferromagnetic Cr2O3 thin film. The Cr2O3 thin film grown on the SrTiO3 substrate comprises high-density nanotwins and exhibits an obvious room-temperature ferrimagnetic property, though the bulk Cr2O3 is intrinsically antiferromagnetic. Aberration-corrected transmission electron microscopy investigations reveal that the twin boundaries (TBs) of Cr2O3 are stoichiometric and have two types of atomic structures (i.e., denoted by type I and type II). First-principles calculations suggest that the type I TB exhibits an antiferromagnetic nature without a net magnetic moment, while the type II TB is ferrimagnetic and has a net magnetic moment of 3.0 μB/f.u. These findings suggest that nanotwins in functional materials can generate physical properties distinct from those of single crystals, thereby providing an efficient strategy for material design and performance control.
Engineered Therapeutic Bacteria with High-Yield Membrane Vesicle Production Inspired by Eukaryotic Membrane Curvature for Treating Inflammatory Bowel Disease
Jinjin Chen - ,
Mingkang Liu - ,
Shiyi Chen - ,
C. Perry Chou - ,
Hongmei Liu *- ,
Decheng Wu *- , and
Yilan Liu *
Bacterial membrane vesicles (BMVs) are emerging as powerful natural nanoparticles with transformative potential in medicine and industry. Despite their promise, scaling up BMV production and ensuring stable isolation and storage remain formidable challenges that limit their broader application. Inspired by eukaryotic mechanisms of membrane curvature, we engineered Escherichia coli DH5α to serve as a high-efficiency BMV factory. By fusing the ethanolamine utilization microcompartment shell protein EutS with the outer membrane via the ompA signal peptide, we induced dramatic membrane curvatures that drove enhanced vesiculation. Simultaneously, overexpression of fatty acyl reductase led to the production of amphiphilic fatty alcohols, further amplifying the BMV yield. Dynamic modulation of peptidoglycan hydrolase (PGase) expression facilitated efficient BMV release, resulting in a striking 149.11-fold increase in vesicle production. Notably, the high-yield BMVs from our engineered strain, without the need for purification, significantly bolstered innate immune responses and demonstrated therapeutic efficacy in treating inflammatory bowel disease (IBD). This study presents a strategy to overcome BMV production barriers, showcasing the therapeutic potential of engineered bacteria and BMVs for IBD treatment, while highlighting their potential applications in diverse biomedical fields.
Machine Learning-Assisted High-Donor-Number Electrolyte Additive Screening toward Construction of Dendrite-Free Aqueous Zinc-Ion Batteries
Haoran Luo - ,
Qianzhi Gou - ,
Yujie Zheng *- ,
Kaixin Wang - ,
Ruduan Yuan - ,
Sida Zhang - ,
Wei Fang - ,
Ziga Luogu - ,
Yuzhi Hu - ,
Huaping Mei - ,
Bingye Song - ,
Kuan Sun - ,
John Wang - , and
Meng Li *
The utilization of electrolyte additives has been regarded as an efficient strategy to construct dendrite-free aqueous zinc-ion batteries (AZIBs). However, the blurry screening criteria and time-consuming experimental tests inevitably restrict the application prospect of the electrolyte additive strategy. With the rise of artificial intelligence technology, machine learning (ML) provides an avenue to promote upgrading of energy storage devices. Herein, we proposed an intriguing ML-assisted method to accelerate the development efficiency of electrolyte additives on dendrite-free AZIBs. Concretely, we selected the Gutmann donor number (DN value) as a screen parameter, which can reflect the interaction between solvent molecules and ions, and proposed an integrated ML model that can predict the DN values of organic molecules via molecular fingerprints, thereby achieving the screening of electrolyte additives. Then, combined with experimental tests and theoretical calculations, the influence law of three additive molecules with different DN values on the thermodynamic stability of the Zn anode and its corresponding optimization mechanisms were revealed; the DN values of the additives are in positive correlation with the electrochemical performance of the Zn anode. Especially, an isopropyl alcohol (IPA) additive with a high DN value (36) integrated with various Zn-based cells presented a superior electrochemical performance, including a high calendar life (1500 h), a stable Coulombic efficiency (99% within 450 cycles), and a favorable cycling retention. This work pioneers ML techniques for predicting DN values for electrolyte additives, offering a compelling investigation method for the investigation of AZIBs.
Single-Atom Suture
Chenyang Wang - ,
Xiang Li - ,
Erli Ni - ,
Wenxuan Yang - ,
Ziyue Zeng - ,
Haiyang Liu - ,
Tingting Cheng - ,
Ting Yu - ,
Mengqi Zeng *- , and
Lei Fu *
In atomically thin two-dimensional (2D) materials, grain boundaries (GBs) are ubiquitous, displaying a profound effect on the electronic structure of the host lattice. The random configuration of atoms within GBs introduces an arbitrary and unpredictable local electronic environment, which may hazard electron transport. Herein, by utilizing the Pt single-atom chains with an ultimate one-dimensional (1D) feature (width of a single atom and length up to tens of nanometers), we realized the suture of the electron pathway at GBs of diversified transition metal dichalcogenides (TMDCs). Theoretical calculations reveal that the construction of Pt single-atom sutures (SAS) prompts the emergence of electronic states proximal to the Fermi level, effectively modulating the transformation of the electronic structure from semiconductivity to metallicity. This transformation underscores the pivotal role of Pt SAS in reconfiguring the electron pathway. Benefiting from this, the Pt SAS–MoS2 emerges as an excellent catalyst, exhibiting an overpotential of 41 mV at 10 mA cm–2 and a Tafel slope of 54 mV dec–1 in hydrogen evolution reaction. Our results offer an understanding of the electron conduction pathway contributed by ultraordered atomic arrangement and the innovative mechanisms for future potential catalysts with an optimized architecture.
Vertical Quantum Confinement in Bulk MoS2
Jairo Obando-Guevara *- ,
Álvaro González-García - ,
Marcin Rosmus - ,
Natalia Olszowska - ,
César González - ,
Miguel Ángel González-Barrio - ,
Antonio Tejeda - , and
Arantzazu Mascaraque
We experimentally observe quantum confinement states in bulk MoS2 by using angle-resolved photoemission spectroscopy (ARPES). The band structure at the Γ̅ point reveals quantum well states (QWSs) linked to vertical quantum confinement of the electrons, confirmed by the absence of dispersion in kz and a strong intensity modulation with the photon energy. Notably, the binding energy dependence of the QWSs versus n does not follow the quadratic dependence of a two-dimensional electron gas. Instead, a linear behavior is observed that is consistent with a parabolic-like quantum well. This confinement arises from the mechanical exfoliation preparation method, which leads to the detachment of a multilayer stack from the underlying bulk. This is confirmed by density functional theory (DFT) calculations. The quantum confinement in bulk-like MoS2 not only offers the opportunity to explore intersubband transitions to exploit optical properties but also provides a means to study fundamental quantum phenomena in multilayer stacks of different thicknesses.
Urea Chelation of I+ for High-Voltage Aqueous Zinc–Iodine Batteries
Cuicui Li - ,
Haocheng Li - ,
Xiuyun Ren - ,
Liang Hu - ,
Jiaojiao Deng - ,
Jinhan Mo - ,
Xiaoqi Sun *- ,
Guohua Chen *- , and
Xiaoliang Yu *
The multielectron conversion electrochemistry of I–/I0/I+ enables high specific capacity and voltage in zinc–iodine batteries. Unfortunately, the I+ ions are thermodynamically unstable and are highly susceptible to hydrolysis. Current endeavors primarily focus on exploring interhalogen chemistry to activate the I0/I+ couple. However, the practical working voltage is below the theoretical level. In this study, the I0/I+ redox couple is fully activated, and I+ is efficiently stabilized by a chelation agent of cost-effective urea in the conventional aqueous electrolyte. A record-high plateau voltage of 1.8 V vs Zn/Zn2+ has been realized. Theoretical calculations combined with spectroscopy studies and electrochemical tests reveal that the coordination between the electron-deficient I+ and the electron-rich O and N atoms in urea molecules is thermodynamically favorable for I0/I+ conversion and inhibits the self-disproportionation of I+, which in turn promotes rapid kinetics and excellent reversibility of I0/I+. Moreover, urea decreases the water activity in the electrolyte by forming hydrogen bonds to further suppress the hydrolysis of I+. Accordingly, a high specific capacity of 419 mAh g–1 is delivered at 1C, and 147 mAh g–1 capacity is retained after 10,000 cycles at 5C. This work offers effective insights into formulating halogen-free electrolytes for high-performance aqueous zinc–iodine batteries.
Platinum(IV)-Backboned Polymer Prodrug-Functionalized Manganese Oxide Nanoparticles for Enhanced Lung Cancer Chemoimmunotherapy via Amplifying Stimulator of Interferon Genes Activation
Li Liu - ,
Shengxiang Fu *- ,
Haojie Gu - ,
Yangqian Li - ,
Guonian Zhu - ,
Hua Ai - , and
Weimin Li *
The stimulator of interferon genes (STING) pathway exhibits great potential in remodeling the immunosuppressive tumor microenvironment and initiating antitumor immunity. However, how to effectively activate STING and avoid undesired toxicity after systemic administration remains challenging. Herein, platinum(IV)-backboned polymer prodrug-coated manganese oxide nanoparticles (DHP/MnO2NP) with pH/redox dual responsive properties are developed to precisely release cisplatin and Mn2+ in the tumor microenvironment and synergistically amplify STING activation. In vitro, we demonstrate that DHP/MnO2NP can effectively induce tumor cell DNA damage and leak into the cytoplasm, cooperating with Mn2+ to promote STING activation and significantly upregulate the expression of proinflammatory cytokines. Additionally, DHP/MnO2NP can selectively release cisplatin and Mn2+ to mediate tumor killing while reducing toxicity to normal cells. In vivo, DHP/MnO2NP exerted increased therapeutic efficacy by inducing STING activation and initiating robust antitumor immunity. Specifically, DHP/MnO2NP effectively skewed tumor-associated macrophages toward a proinflammatory phenotype and upregulated the expression of proinflammatory cytokines in tumors by up to 99-fold relative to the control. And the infiltration of CD8+ T cells was also significantly increased. When STING signaling was blocked, the antitumor effects and immunostimulatory efficacy of DHP/MnO2NP were significantly inhibited. Moreover, DHP/MnO2NP possess the advantage of enhanced tumor homing and retention, resulting in stronger and longer-lasting anticancer effects. Overall, DHP/MnO2NP provide a potential platform for potentiating cancer chemoimmunotherapy and hold promise for precision treatment.
Strongly Coupled Interface in Electrostatic Self-Assembly Covalent Triazine Framework/Bi19S27Br3 for High-Efficiency CO2 Photoreduction
Jiajing Zhang - ,
Mei Zheng - ,
Yao Wu - ,
Jun Xiong *- ,
Shuzhou Li - ,
Wei Jiang *- ,
Zheng Liu *- , and
Jun Di *
Constructing a strong bonded interface is highly desired to build fast charge-transfer channels and tune reactive sites for optimizing CO2 photoreduction. In this work, a covalent triazine framework (CTF) combined with a Bi19S27Br3 heterojunction is designed using an electrostatic self-assembly process. Due to the oppositely charged states between two components and ultrasonic treatment, a strong coupled interface is realized with the formation of Bi–C/N/O bonds, leading to robust interfacial polarization. This feature causes interfacial charge redistribution, intensifies the interaction between triazine N reactive sites and CO2, stabilizes the intermediate state, and lowers the reaction energy barrier. Meanwhile, the chemically bonded interface favors rapid electron migration from Bi19S27Br3 to CTF, as proved by ultrafast transient absorption spectroscopy and in situ irradiation XPS. As a result, CTF/Bi19S27Br3 delivers a superior CO2 photoreduction performance to yield CO (572.2 μmol g–1 h–1) in a pure water system, which is 38.6 times that of Bi19S27Br3, with apparent quantum yields up to 7.9 and 6.2% at 380 and 400 nm, respectively. This strong interfacial coupling strategy provides an accessible pathway to designing interfacial polarized, high-efficiency photocatalysts.
Intercalation-Induced Interlayer and Defect Engineering in Ti3C2Tx MXene for Ultralow-Reflection Electromagnetic Interference Shielding
Ruosong Li - ,
Youpeng Huangfu - ,
Lulu Liu - ,
Jiashun Hu - ,
Dan Zeng *- ,
Yichen Wang - ,
Daidi Fan *- ,
Rui Zhang - , and
Biao Zhao *
Interlayer and defect engineering significantly affects the electrical conductivity and electromagnetic interference (EMI) shielding of Ti3C2Tx MXene. Previous studies have prioritized the size of the intercalant over its synergy with chemical affinity, limiting the elucidation of the intercalation mechanism and the precise control of the interlayer spacing (d-spacing). Herein, we synthesize MXene aerogels with a tunable d-spacing and defect density using a series of amine molecules of different sizes and chemical affinities as intercalants and cross-linkers. Particularly, the intercalation of p-phenylenediamine (PPD) increases the d-spacing of MXene from 0.960 to 1.642 nm. Simultaneously, the increased d-spacing contributes to an increased defect density within the Ti–Ti layer. Hence, the PPD@MXene aerogel exhibits reduced surface electric field intensity and increased internal polarization loss, resulting in absorption-dominated EMI shielding. The absorptivity reaches 0.92, far exceeding the reported shielding materials, with a shielding effectiveness of 50.4 dB. This study provides a theoretical foundation and preliminary guidance for the development of interlayer-engineered MXene shielding materials.
Bio-Orchestration of Cellular Organization and Human-Preferred Sensory Texture in Cultured Meat
Sungwon Jung - ,
Bumgyu Choi - ,
Milae Lee - ,
Sohyeon Park - ,
Woojin Choi - ,
Hyungseok Yong - ,
Sung-eun Heo - ,
Yeseul Park - ,
Jeong Min Lee - ,
Seung Tae Lee - ,
Heeyoun Hwang - ,
Jae-Sung Kwon - ,
Won-Gun Koh *- , and
Jinkee Hong *
For cultured meat to effectively replace traditional meat, it is essential to develop scaffolds that replicate key attributes of real meat, such as taste, nutrition, flavor, and texture. However, one of the significant challenges in replicating meat characteristics with scaffolds lies in the considerable gap between the stiffness preferred by cells and the textural properties desired by humans. To address this issue, we focused on the microscale environment conducive to cell growth and the macro-scale properties favored by humans. This led to the development of the adaptive bio-orchestrating anisotropic scaffold (ABS), which satisfies both cellular and human requirements. The ABS is produced using the anisotropic freeze-initiated ion coordination method, which sequentially aligns and enhances the fibril structure of food-derived proteins, effectively bridging the gap between cellular and culinary perspectives. Notably, the microenvironments of the ABS exhibited exceptional myoblast cell differentiation, with macro-scale 3D mechanical textures that are consistent regardless of the chewing direction, due to the aligned fibril and cell structure. The ABS containing bovine myotubes demonstrated a mechanical texture nearly identical to that of beef sirloins.
Charge Regulation-Enhanced Type I Photosensitizer-Loaded Hydrogel Dressing for Hypoxic Bacterial Inhibition and Biofilm Elimination
Tao Xiong - ,
Fangrui Ning - ,
Yingchao Chen - ,
Mingrui Gu - ,
Mingle Li - ,
Xiaoqiang Chen *- ,
Lei Wang - ,
Jiangli Fan - , and
Xiaojun Peng *
Biofilm-induced chronic bacterial infections represent a significant challenge in modern medicine due to their resistance to conventional antibiotic treatments. Although photodynamic therapy (PDT) has emerged as a promising antibiotic-free antibacterial strategy, the hypoxic condition within biofilms and the lack of an effective local drug delivery system have limited the clinical effectiveness of photosensitizer (PS) agents. Herein, we propose a type of charge regulation-enhanced type I PS-loaded hydrogel dressing for treating biofilm infection. The charge regulation enables the multiple alkylation Nile blue (EB series) to exhibit substantially improved absorbance (∼2-fold), alkaline tolerance, and superoxide anion yield (2.2–4.2-fold) compared to the representative type I PS, sulfur-substituted Nile blue. Specifically, the enhanced electronic push–pull capabilities promote a more efficient electron recycling process, significantly boosting the efficiency of type I PDT. The superior PDT effect and enhanced bacterial uptake via charge regulation render the EB series more pronounced in hypoxic bacterial inhibition under red light or sunlight irradiation. Moreover, the hydrogel, constructed from oxidized dextran and quaternized chitosan, facilitates the localization and sustained retention of type I PSs, accelerating the healing of biofilm-infected wounds. This type I PS-based hydrogel could provide an efficient and user-friendly wound dressing for the clinical treatment and prevention of biofilm infections.
Visible Light Spectroscopy of Liquid Solutes from Femto- to Attoliter Volumes Inside a Single Nanofluidic Channel
Björn Altenburger - ,
Joachim Fritzsche - , and
Christoph Langhammer *
This publication is Open Access under the license indicated. Learn More
UV–vis spectroscopy is a workhorse in analytical chemistry that finds application in life science, organic synthesis, and energy technologies like photocatalysis. In its traditional implementation with cuvettes, it requires sample volumes in the milliliter range. Here, we show how nanofluidic scattering spectroscopy (NSS), which measures visible light scattered from a single nanochannel in a spectrally resolved way, can reduce this sample volume to the attoliter range for solute concentrations in the mM regime, which corresponds to as few as 105 probed molecules. The connection of the nanochannel to a microfluidic in-and-outlet system enables such measurements in continuous flow conditions, and the integrated online optical reference system ensures their long-term stability. On the examples of the nonabsorbing solutes NaCl and H2O2 and the dyes Brilliant Blue, Allura Red, and Fluorescein, we demonstrate that spectral fingerprints can be obtained with good accuracy and that solute concentrations inside the nanochannel can be determined based on NSS-spectra. Furthermore, by applying a reverse Kramers–Kronig transformation to NSS-spectra, we show that the molar extinction coefficient of the dye solutes can be extracted in good agreement with the literature values. These results thus advertise NSS as a versatile tool for the spectroscopic analysis of solutes in situations where nanoscopic sample volumes, as well as continuous flow measurements are critical, e.g., in single particle catalysis or nanoscale flow cytometry.
Nanoencapsulation of Living Microbial Cells in Porous Covalent Organic Framework Shells
Chen Li - ,
Mengchu Feng - ,
Bixiao Li - ,
Xiao Feng - ,
Yuanyuan Zhang *- , and
Bo Wang *
Encapsulating living cells within nanoshells offers an important approach to enhance their stability against environmental stressors and broaden their application scope. However, this often leads to impaired mass transfer at the cell biointerface. Strengthening the protective shell with well-defined, ordered transport channels is crucial to regulating molecular transport and maintaining cell viability and biofunctionality. Herein, we report the construction of covalent organic framework (COF) mesoporous shells for single-cell nanoencapsulation, providing selective permeability and comprehensive protection for living microbial cells. The COF shells ensure nutrient uptake while blocking large harmful molecules and UV-C radiation, thereby preserving cell viability and metabolic activity. Integration of such crystalline porous shells with genetically modified cell factories for metabolic production is further investigated, revealing no adverse effects, as demonstrated by riboflavin production. Moreover, the COF shell effectively shields cells, ensuring efficient bioproduction even after being treated under harsh conditions. This versatile encapsulation approach is applicable for different cell types, providing a robust platform for cell surface engineering.
Aqueous Alkaline Zinc–Iodine Battery with Two-Electron Transfer
Xinliang Li - ,
Tong Liu - ,
Pei Li - ,
Guojin Liang - ,
Zhaodong Huang - ,
Ze Chen - ,
Ao Chen - ,
Yuefeng Su - ,
Lijiang Yang - ,
Duanyun Cao *- , and
Chunyi Zhi *
While many cathode materials have been developed for mild electrolyte-based Zn batteries, the lack of cathode materials hinders the progress of alkaline zinc batteries. Halide iodine, with its copious valence nature and redox possibilities, is considered a promising candidate. However, energetic alkaline iodine redox chemistry is impeded by an alkali-unadapted I2 element cathode and thermodynamically unstable reaction products. Here, we formulated and evaluated an aqueous alkaline Zn–iodine battery with a two-electron transfer employing an organic iodized salt cathode and a Cl–-manipulated electrolyte. The single-step redox reaction of the I–/I+ couple resulted in a high discharge plateau of 1.68 V and a capacity of 385 mA h g–1. Our battery reached an energy density of 577 W h kg–1, superior to that of reported counterparts. Theoretical and experimental characterizations determined the redox chemistry between alkaline and iodine. We believe the developed iodine chemistry in alkaline environments can enrich cathode materials for alkaline batteries.
Donkey-Hide Gelatin-Derived Carbon Dots Activate Erythropoiesis and Eliminate Oxidative Stress for Aplastic Anemia Treatment
Chunzhen Wang - ,
Jinghui Li - ,
Kehan Liu - ,
Junjin Li - ,
Fan Zhang - ,
Xiaomin Ma - ,
Yuezheng Li - ,
Chengmei Zhang - ,
Xiangdong Liu - ,
Yuanyuan Qu - ,
Mingwen Zhao - ,
Weifeng Li - ,
Weimin Huang *- , and
Yong-Qiang Li *
Aplastic anemia (AA) is a life-threatening hematologic disease with limited therapeutic options. Stalled erythropoiesis and oxidative stress-induced hemocyte apoptosis are the main pathological features of AA, yet therapeutic agents that address these issues remain elusive. In this study, we report distinctive donkey-hide gelatin-derived carbon dots (G-CDs) that enable erythropoiesis activation and oxidative stress elimination to tackle refractory AA. We demonstrate that G-CDs can promote the proliferation and erythroid differentiation of hematopoietic stem cells as well as erythrocyte maturation, activating the whole process of erythropoiesis. Moreover, G-CDs display multienzyme-like activities and dramatically alleviate the oxidative stress of bone marrow and peripheral blood via catalytic scavenging of multiple reactive oxygen species, reconstructing the hematopoietic microenvironment. Intravenously or orally administered to AA mice induced by chemotherapy drugs, G-CDs significantly boost the level of red blood cells and hemoglobin and lead to the complete recovery of hematopoietic function, showing better therapeutic performance than clinically approved erythropoietin (EPO) without adverse effects. By collaboratively addressing the issues of stalled erythropoiesis and oxidative stress, the G-CDs-based intervention strategy may offer a powerful paradigm for clinical AA management.
January 6, 2025
Immobile Integrin Signaling Transit and Relay Nodes Organize Mechanosignaling through Force-Dependent Phosphorylation in Focal Adhesions
Kashish Jain - ,
Kishan Kishan - ,
Rida F. Minhaj - ,
Pakorn Kanchanawong - ,
Michael P. Sheetz - , and
Rishita Changede *
Transmembrane signaling receptors, such as integrins, organize as nanoclusters that provide several advantages, including increasing avidity, sensitivity (increasing the signal-to-noise ratio), and robustness (signaling threshold) of the signal in contrast to signaling by single receptors. Furthermore, compared to large micron-sized clusters, nanoclusters offer the advantage of rapid turnover for the disassembly of the signal. However, whether nanoclusters function as signaling hubs remains poorly understood. Here, we employ fluorescence nanoscopy combined with photoactivation and photobleaching at subdiffraction limited resolution of ∼100 nm length scale within a focal adhesion to examine the dynamics of diverse focal adhesion proteins. We show that (i) subregions of focal adhesions are enriched in an immobile population of integrin β3 organized as nanoclusters, which (ii) in turn serve to organize nanoclusters of associated key adhesome proteins-vinculin, focal adhesion kinase (FAK) and paxillin, demonstrating that signaling proceeds by formation of nanoclusters rather than through individual proteins. (iii) Distinct focal adhesion protein nanoclusters exhibit distinct protein dynamics, which is closely correlated to their function in signaling. (iv) Long-lived nanoclusters function as signaling hubs─wherein immobile integrin nanoclusters organize phosphorylated FAK to form stable nanoclusters in close proximity to them, which are disassembled in response to inactivation signal by removal of force and in turn activation of phosphatase PTPN12. (v) Signaling takes place in response to external signals such as force or geometric arrangement of the nanoclusters and when the signal is removed, these nanoclusters disassemble. We term these functional nanoclusters as integrin signaling transit and relay nodes (STARnodes). Taken together, these results demonstrate that integrin STARnodes seed signaling downstream of the integrin receptors by organizing hubs of signaling proteins (FAK, paxillin, vinculin) to relay the incoming signal intracellularly and bring about robust function.
Lab-on-the-Needles: A Microneedle Patch-Based Mobile Unit for Highly Sensitive Ex Vivo and In Vivo Detection of Protein Biomarkers
Ying-Pei Hsu - ,
Nan-Si Li - ,
Hao-Han Pang - ,
Yu-Chi Pan - ,
Hung-Pei Tsai - ,
Hsiao-Chien Chen - ,
Ying-Tzu Chen - ,
Chen-Hsun Weng - ,
Shiao-Wei Kuo *- , and
Hung-Wei Yang *
This publication is Open Access under the license indicated. Learn More
Detection of biomarkers associated with physiological conditions provides critical insights into healthcare and disease management. However, challenges in sampling and analysis complicate the detection and quantification of protein biomarkers within the epidermal layer of the skin and in viscous liquid biopsy samples. Here, we present the “Lab-on-the-Needles” concept, utilizing a microneedle patch-based sensing box (MNP-based SenBox) for mobile healthcare applications. This system facilitates the rapid capture of protein biomarkers directly from the in situ epidermal layer of skin or liquid biopsies, followed by on-needle analysis for immediate assessment. The integration of horseradish peroxidase-incorporated zeolitic imidazolate framework-8 (HRP@ZIF-8) as a sensitive and stable signal probe, the detection limit for anti-SARS-CoV-2 NP IgA antibodies and various SARS-CoV-2 S1P mutant strains improves by at least 1,000-fold compared to FDA-approved commercial saliva lateral flow immune rapid tests. Additionally, the MNP-based SenBox demonstrated minimally invasive monitoring and rapid quantification of inflammatory cytokine levels (TNF-α and IL-1β) in rats within 30 min using a portable ColorReader. This study highlights the potential of the MNP-based SenBox for the minimally invasive collection and analysis of protein biomarkers directly from in situ epidermal layers of skin or liquid biopsies that might facilitate mobile healthcare diagnostics and longitudinal monitoring.
Engineering the Thermal and Energy-Storage Properties in Quantum Dots Using Dominant Faceting: The Case Study of Silicon
Pavel Galář - ,
Jakub Kopenec - ,
Robert Král - ,
Filip Matějka - ,
Petra Zemenová - ,
Milan Dopita - ,
Prokop Hapala - ,
Dirk König - ,
Pavel Vrbka - , and
Kateřina Kůsová *
This publication is Open Access under the license indicated. Learn More
The storage and release of energy is an economic cornerstone. In quantum dots (QDs), energy storage is mostly governed by their surfaces, in particular by surface chemistry and faceting. The impact of surface free energy (SFE) through surface faceting has already been studied in QDs. Here, we introduce dominant faceting representing the structural order of the surface. In particular, we propose that realistic QDs attain complicated polyhedral quasi-spherical shapes while keeping the dominance of a certain type of facet. The type of dominant facet determines the rates of surface-related processes. Therefore, by connecting dominant faceting with SFE, trends analogical to bulk material are kept despite the lack of evident microscopic shape control. To demonstrate the applicability of dominant faceting, we synthesize sets of silicon QDs with sizes around 5 nm and classify them based on increasing SFE of the corresponding analytic geometrical models, using a detailed surface chemistry analysis. Total energies released during oxidation of the synthesized QDs reach the theoretical limit, unlike in the reference, “large” (>100 nm) silicon nanoparticles, which release about 15% less energy. Next, we perform a comprehensive experimental study of dehydrogenation and thermal oxidation of the synthesized QDs in the temperature range of 25–1100 °C, identifying SFE as the key factor determining their thermal stability and surface reactivity. In particular, four distinctive stages of energy release were observed with onset temperatures ranging between 140 and 250 °C, ≈500 and 650–700 °C, respectively, for the SFE-differing samples. Finally, the thermal oxidation of the synthesized QDs is completed at lower temperatures with increasing SFE, decreasing from 1065 to 970 °C and being > 150 °C lower in QDs than in the larger reference nanoparticles. Therefore, despite a rich mixture of features, our description based on linking dominant faceting with SFE allows us to fully explain all the observed trends, demonstrating both the potential of SFE-based engineering of energy-storage properties in QDs and the prospects of silicon QDs as an energy-storage material.
Edge-Energy-Driven Growth of Monolayer MnI2 Islands on Ag(111): High-Resolution Imaging and Theoretical Analysis
Daniel Rothhardt - ,
Christopher Penschke - ,
Hans Josef Hug - ,
Regina Hoffmann-Vogel - , and
Amina Kimouche *
This publication is Open Access under the license indicated. Learn More
The reduced dimensionality of thin transition metal dihalide films on single-crystal surfaces unlocks a diverse range of magnetic and electronic properties. However, achieving stoichiometric monolayer islands requires precise control over the growth conditions. In this study, we employ scanning probe microscopy to investigate the growth of MnI2 on Ag(111) via single-crucible evaporation. The catalytic properties of the Ag(111) surface facilitate MnI2 dehalogenation, leading to the formation of a reconstructed iodine adlayer that acts as a buffer layer for the growth of truncated hexagonal MnI2 islands. These islands exhibit alternating edge lengths and distinct Kelvin potentials, as revealed by Kelvin probe force microscopy. Density functional theory (DFT) calculations support the experimentally observed island heights and lattice parameters and provide insights into the formation energies of both pristine and reconstructed edges. The asymmetry in edge lengths is attributed to differences in edge formation energies, driven by the position (up or down) of edge iodine atoms, as confirmed by DFT. This structural difference accounts for the observed variation in the Kelvin potential between the two types of island edge terminations.
Targeted Covalent Nanodrugs Reinvigorate Antitumor Immunity and Kill Tumors via Improving Intratumoral Accumulation and Retention of Doxorubicin
Zhijia Zhu - ,
Yanxue Shang - ,
Chukai Lin - ,
Dongchen Zhang - ,
Lili Ai - ,
Youshan Li - ,
Weihong Tan *- ,
Yanlan Liu *- , and
Zilong Zhao *
Specifically improving the intratumoral accumulation and retention and achieving the maximum therapeutic efficacy of small-molecule chemotherapeutics remains a considerable challenge. To address the issue, we here reported near-infrared (NIR) irradiation-activatable targeted covalent nanodrugs by installing diazirine-labeled transferrin receptor 1 (TfR1)-targeted aptamers on PEGylated phospholipid-coated upconversion nanoparticles followed by doxorubicin loading. Targeted covalent nanodrugs recognized and then were activated to covalently cross-link with TfR1 on cancer cells by 980 nm NIR irradiation. Systematic studies revealed that they achieved >6- and >5.5-fold higher intratumoral accumulations of doxorubicin than aptamer-based targeted nanodrugs at 6 and 120 h post intravenous injection, respectively. Based on high drug delivery efficacy, targeted covalent nanodrugs boosted doxorubicin-induced immunogenic cell death, activated antitumor immune responses and shrank the sizes of both primary and distant tumors, and displayed better therapeutic efficacy and less adverse effect than targeted nanodrugs and commercial Doxil in 4T1 syngeneic breast tumor model featuring an immunosuppressive microenvironment. By integrating the specificity of molecular recognition, the reactivity profile of diazirine and the accuracy of light manipulation with nanodrug supremacy, our targeted covalent nanodrugs could be expected as a longer-term and efficient strategy to improve anticancer therapeutic efficacy of chemotherapeutics.
Strain-Reduced Inversion Symmetry in Ultrathin SnP2Se6 Crystals for Giant Bulk Piezophotovoltaic Generation
Chengyi Zhu - ,
Wen He - ,
Zhen-Rong Huang - ,
Bingxuan Zhu - ,
Lin-Qing Yue - ,
Pei-Yu Huang - ,
Dong Li - ,
Jinzhong Wang - ,
Liang Zhen - ,
Jing-Kai Qin *- , and
Cheng-Yan Xu *
With the potential to surpass the Shockley–Queisser (S–Q) limitation for solar energy conversion, the bulk photovoltaic (BPV) effect, which is induced by the broken inversion symmetry of the lattice, presents prospects for future light-harvesting technologies. However, the development of BPV is largely limited by the low solar spectrum conversion efficiency of existing noncentrosymmetric materials with wide band gaps. This study reports that the strain-induced reduction of inversion symmetry can enhance the second-order nonlinear susceptibility (χ(2)) of SnP2Se6 crystals by an order of magnitude, which contributes to an extremely high value of 1.3 × 10–8 m·V–1 under 1550 nm excitation, and is high among two-dimensional (2D) crystals. More importantly, owing to the orientation-dependent reduction of lattice symmetry, the BPV generation induced by strain, referred to as the bulk piezophotovoltaic effect, is demonstrated in the SnP2Se6 crystal with strong in-plane anisotropy. The strain along the Se zigzag direction greatly facilitates the generation of the giant photocurrent covering an extended spectrum ranging from 400 to 1100 nm, resulting in leading-level values of the BPV coefficient among noncentrosymmetric crystals, while the BPV effect is barely modulated along the Se armchair direction even with a large strain of 0.57%. This study highlights the potential of the bulk piezophotovoltaic effects for energy conversion efficiency and offers a promising strategy for the design of next-generation light-harvesting devices.
Highly Crystalline Contorted Coronene Homologous Molecule as Superior Organic Anode Material for Full-Cell Li-Ion Batteries
Jee Ho Ha - ,
Minsung Kang - ,
Hyunji Cha - ,
Jaehyun Park - ,
Minju Lee - ,
Se Hun Joo - ,
Seokhoon Ahn *- , and
Seok Ju Kang *
Organic anode materials have garnered attention for use in rechargeable Li-ion batteries (LIBs) owing to their lightweight, cost-effectiveness, and tunable properties. However, challenges such as high electrolyte solubility and limited conductivity, restrict their use in full-cell LIBs. Here, we report the use of highly crystalline Cl-substituted contorted hexabenzocoronene (Cl-cHBC) as an efficient organic anode for full-cell LIBs. By employing an antisolvent crystallization method, the crystallinity of the Cl-cHBC materials has been significantly enhanced, achieving superior electrochemical performance in a half-cell configuration. Furthermore, when incorporated with the conventional lithium iron phosphate (LFP) cathode, the Cl-cHBC||LFP full-cell delivers a high discharge cell voltage of 3.0 V, surpassing the voltages of conventional lithium–titanium oxide anodes and offering improved power densities. In addition, a full cell with high-voltage lithium cobalt oxide and single-crystal high-nickel-based cathodes demonstrates enhanced electrochemical characteristics, including elevated discharge voltages, stable C-rate performance, and cycle endurance. Thus, the proposed highly crystalline Cl-cHBC anode is a promising next-generation solution for LIB applications.
Photocatalytic Semiconductor–Metal Hybrid Nanoparticles: Single-Atom Catalyst Regime Surpasses Metal Tips
Shira Gigi - ,
Tal Cohen - ,
Diego Florio - ,
Adar Levi - ,
David Stone - ,
Ofer Katoa - ,
Junying Li - ,
Jing Liu - ,
Sergei Remennik - ,
Franco V. A. Camargo - ,
Giulio Cerullo - ,
Anatoly I. Frenkel - , and
Uri Banin *
This publication is Open Access under the license indicated. Learn More
Semiconductor–metal hybrid nanoparticles (HNPs) are promising materials for photocatalytic applications, such as water splitting for green hydrogen generation. While most studies have focused on Cd containing HNPs, the realization of actual applications will require environmentally compatible systems. Using heavy-metal free ZnSe-Au HNPs as a model, we investigate the dependence of their functionality and efficiency on the cocatalyst metal domain characteristics ranging from the single-atom catalyst (SAC) regime to metal-tipped systems. The SAC regime was achieved via the deposition of individual atomic cocatalysts on the semiconductor nanocrystals in solution. Utilizing a combination of electron microscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy, we established the presence of single Au atoms on the ZnSe nanorod surface. Upon increased Au concentration, this transitions to metal tip growth. Photocatalytic hydrogen generation measurements reveal a strong dependence on the cocatalyst loading with a sharp response maximum in the SAC regime. Ultrafast dynamics studies show similar electron decay kinetics for the pristine ZnSe nanorods and the ZnSe-Au HNPs in either SAC or tipped systems. This indicates that electron transfer is not the rate-limiting step for the photocatalytic process. Combined with the structural-chemical characterization, we conclude that the enhanced photocatalytic activity is due to the higher reactivity of the single-atom sites. This holistic view establishes the significance of SAC-HNPs, setting the stage for designing efficient and sustainable heavy-metal-free photocatalyst nanoparticles for numerous applications.
Autonomous Nucleic Acid and Protein Nanocomputing Agents Engineered to Operate in Living Cells
Martin Panigaj - ,
Tanaya Basu Roy - ,
Elizabeth Skelly - ,
Morgan R. Chandler - ,
Jian Wang - ,
Srinivasan Ekambaram - ,
Kristin Bircsak - ,
Nikolay V. Dokholyan *- , and
Kirill A. Afonin *
This publication is Open Access under the license indicated. Learn More
In recent years, the rapid development and employment of autonomous technology have been observed in many areas of human activity. Autonomous technology can readily adjust its function to environmental conditions and enable an efficient operation without human control. While applying the same concept to designing advanced biomolecular therapies would revolutionize nanomedicine, the design approaches to engineering biological nanocomputing agents for predefined operations within living cells remain a challenge. Autonomous nanocomputing agents made of nucleic acids and proteins are an appealing idea, and two decades of research has shown that the engineered agents act under real physical and biochemical constraints in a logical manner. Throughout all domains of life, nucleic acids and proteins perform a variety of vital functions, where the sequence-defined structures of these biopolymers either operate on their own or efficiently function together. This programmability and synergy inspire massive research efforts that utilize the versatility of nucleic and amino acids to encode functions and properties that otherwise do not exist in nature. This Perspective covers the key concepts used in the design and application of nanocomputing agents and discusses potential limitations and paths forward.
Ion-Induced Phase Changes in 2D MoTe2 Films for Neuromorphic Synaptic Device Applications
Rifat Hasan Rupom - ,
Moonyoung Jung - ,
Anil Pathak - ,
Jeongmin Park - ,
Eunho Lee - ,
Hyeon-Ah Ju - ,
Young-Min Kim - ,
Oliver Chyan - ,
Jungkwun Kim - ,
Dongseok Suh *- , and
Wonbong Choi *
Two-dimensional molybdenum ditelluride (2D MoTe2) is an interesting material for artificial synapses due to its unique electronic properties and phase tunability in different polymorphs 2H/1T′. However, the growth of stable and large-scale 2D MoTe2 on a CMOS-compatible Si/SiO2 substrate remains challenging because of the high growth temperature and impurity-involved transfer process. We developed a large-scale MoTe2 film on a Si/SiO2 wafer by simple sputtering followed by lithium-ion intercalation and applied it to artificial synaptic devices. The Al2O3 passivation layer allows us to develop a stable 1T′-MoTe2 phase by preventing Te segregation caused by the weak bonding between Mo and Te atoms during lithiation. The lithiated MoTe2 film exhibits excellent synaptic behavior such as long-term potentiation/depression, a high Ion/Ioff ratio (≈103) at lower sweep voltage, and long-term retention. The in situ Raman analysis along with a systematic microstructural analysis reveals that the intercalated Li ion can provide an efficient pathway for conducting filament formation.
Accurate DNA Sequence Prediction for Sorting Target-Chirality Carbon Nanotubes and Manipulating Their Functionalities
Xuan Zhou - ,
Pengbo Wang - ,
Yinong Li - ,
Yaoxuan Han - ,
Jianying Chen - ,
Kunpeng Tang - ,
Lei Shi - ,
Yi Zhang - ,
Rui Zhang *- , and
Zhiwei Lin *
Synthetic single-wall carbon nanotubes (SWCNTs) contain various chiralities, which can be sorted by DNA. However, finding DNA sequences for this purpose mainly relies on trial-and-error methods. Predicting the right DNA sequences to sort SWCNTs remains a substantial challenge. Moreover, it is even more daunting to predict sequences for sorting SWCNTs with target chirality. Here, we present a deep-learning (DL) enhanced strategy for the accurate prediction of DNA sequences capable of sorting target-chirality nanotubes. We first experimentally screened 216 DNA sequences using aqueous two-phase (ATP) separation, resulting in 116 resolving sequences that can purify 17 distinct single-chirality SWCNTs. These experimental results created a comprehensive training data set. We utilized the recently released 3D molecular representation learning framework, Uni-Mol, to construct a DL workflow that maps atomistic-level structural information on DNA sequences into the feature space. This information captures the structural features of DNA molecules that are crucial for their interactions with SWCNTs. This may account for the superior performance of our DL models. The models successfully predicted resolving sequences for (6,5), (6,6), and (7,4) SWCNTs with accuracy rates of 87.5, 90, and 70%, respectively. Importantly, the discovery of numerous resolving sequences for (6,5) SWCNTs allows us to systematically manipulate the sequence-dependent absorption spectral shift, photoluminescence intensity, and surfactant sensitivity of DNA-(6,5) hybrids and elucidate the underlying mechanisms.
Poly(p-Phenylene Benzobisoxazole) Nanofiber: A Promising Nanoscale Building Block Toward Extremely Harsh Conditions
Baolong Yuan - ,
Bin Yang *- ,
Ping Xu - , and
Meiyun Zhang *
Since the invention and commercialization of poly(p-phenylene benzobisoxazole) (PBO) fibers, numerous breakthroughs in applications have been realized both in the military and aerospace industries, attributed to its superb properties. Particularly, PBO nanofibers (PNFs) not only retain the high performance of PBO fiber but also exhibit impressive nanofeatures and desirable processability, which have been extensively applied in extreme scenarios. However, no review has yet comprehensively summarized the preparation, applications, and prospective challenges of PNFs to the best of our knowledge. Herein, the two fabrication pathways to acquire PNFs from bottom-up to top-down approaches are critically overviewed; the significant advantages and the problem caused simultaneously of the protonation approach compared with other methods are revealed. Besides, the construction strategies of multidimensional PNF-based advanced composites, including 1D fiber, 2D film/nanopaper, and 3D gel, are discussed. Moreover, the outstanding mechanical, insulating, and thermal stability properties of PNFs facilitate their extensive applications in thermal protection, electrical insulation, batteries, and flexible wearable devices, which are further comprehensively introduced. Finally, the perspective and challenges of the fabrication and application of PNFs are highlighted. It demonstrates that the PNFs as one of the promising high-performance nanoscale building blocks can be fully competent using extremely harsh conditions.
Discovery and Characterization of a Metastable Cubic Interstitial Nickel–Carbon System with an Expanded Lattice
Albert Gili *- ,
Martin Kunz - ,
Daniel Gaissmaier - ,
Christoph Jung - ,
Timo Jacob - ,
Thomas Lunkenbein - ,
Walid Hetaba - ,
Kassiogé Dembélé - ,
Sören Selve - ,
Reinhard Schomäcker - ,
Aleksander Gurlo - , and
Maged F. Bekheet
This publication is Open Access under the license indicated. Learn More
Metastable, i.e., kinetically favored but thermodynamically not stable, interstitial solid solutions of carbon in iron are well-understood. Carbon can occupy the interstitial atoms of the host metal, altering its properties. Alloying of the host metal results in the stabilization of the FeCx phases, widening its application. Pure nickel finds niche applications, mainly focusing on catalysis, while nickel alloys are widely applied, e.g., in gas turbines, reactors, and seawater piping. Nickel carbide (Ni3C) is the well-known stable Ni–C system displaying a rhombohedral (R3̅c) crystal structure. Some reports describe an elusive cubic Ni–C system, observed during certain catalytic reactions occurring on nickel and formed by the occupation of the interstitials of the metal with carbon: to date, the stabilization and characterization of this phase have not been accomplished. Hereby, we report on the synthesis of a cubic metastable NiCx phase using chemical vapor deposition of methane on supported nickel nanoparticles. The structure was predicted by DFT/ReaxFF, synthesized and monitored with in situ time-resolved synchrotron XRD, and experimentally confirmed by Rietveld refinement and (S)TEM-EELS under ambient conditions. The results show an Fm3̅m phase with a lattice parameter of a = 3.749 ± 0.037 Å at room temperature, with the highest ever reported atomic percentage of carbon occupying the octahedral interstices of 23.1%, resulting in a NiC0.3 phase. The degree of occupation of the interstitial voids by carbon can be controlled, enabling the tuning of the host metal’s d-spacing and composition, highlighting the applicability of this synthesis route for catalytic nanoparticle preparation.
Nanospace Engineering for C8 Aromatic Isomer Separation
Nengxiu Zhu - ,
Jiayi Wu - , and
Dan Zhao *
C8 aromatic isomers, namely para-xylene (PX), meta-xylene (MX), ortho-xylene (OX), and ethylbenzene (EB), are essential industrial chemicals with a wide range of applications. The effective separation of these isomers is crucial across various sectors, including petrochemicals, pharmaceuticals, and polymer manufacturing. Traditional separation methods, such as distillation and solvent extraction, are energy-intensive. In contrast, selective adsorption has emerged as an efficient technique for separating C8 aromatic isomers, in which nanospace engineering offers promising strategies to address existing challenges by precisely tailoring the structures and properties of porous materials at the nanoscale. This review explores the application of nanospace engineering in modifying the pore structures and characteristics of diverse porous materials─including zeolites, metal–organic frameworks (MOFs), covalent organic frameworks (COFs), and other porous substances─to enhance their performance in C8 aromatic isomer separation. Additionally, this review provides a comprehensive summary of how different separation techniques, temperature fluctuations, enthalpy/entropy considerations, and desorption processes influence separation efficiency. It also presents a forward-looking perspective on remaining challenges and potential opportunities for advancing C8 aromatic isomer separation.
Cell-Penetrating Peptide Like Anti-Programmed Cell Death-Ligand 1 Peptide Conjugate-Based Self-Assembled Nanoparticles for Immunogenic Photodynamic Therapy
Jun-Hyuck Lee - ,
Seong-Bin Yang - ,
Seong Jin Park - ,
Seho Kweon - ,
Gaeun Ma - ,
Minho Seo - ,
Ha Rin Kim - ,
Tae-Bong Kang - ,
Ji-Hong Lim *- , and
Jooho Park *
The tumor-specific efficacy of the most current anticancer therapeutic agents, including antibody-drug conjugates (ADCs), oligonucleotides, and photosensitizers, is constrained by limitations such as poor cell penetration and low drug delivery. In this study, we addressed these challenges by developing, a positively charged, amphiphilic Chlorin e6 (Ce6)-conjugated, cell-penetrating anti-PD-L1 peptide nanomedicine (CPPD1) with enhanced cell and tissue permeability. The CPPD1 molecule, a bioconjugate of a hydrophobic photosensitizer and strongly positively charged programmed cell death-ligand 1 (PD-L1) binding cell-penetrating peptide (CPP), is capable of self-assembling into nanoparticles with an average size of 199 nm in aqueous solution without the need for any carriers. These carrier-free nanoparticles possess the ability to penetrate the cell membrane of cancer cells and target tumors expressing PD-L1 on their surface. Notably, CPPD1 nanoparticles effectively blocked programmed cell death-1 (PD-1)/PD-L1 interactions and reduced PD-L1 expression via lysosomal degradation. They also demonstrated the responsiveness of CPPD1 nanoparticles in photodynamic therapy (PDT) to a 635 nm laser, leading to the generation of ROS, and induction of various immunogenic cell deaths (ICD). Highly penetrating CPPD1 nanoparticles could immunogenically modulate the microenvironment of CT26 cancer and were also effective in treating abscopal metastatic tumors, addressing major limitations of traditional PDT.
Solar-Driven Nanofluidic Ion Regulation for Fractional Salt Crystallization and Reutilization
Wei Zhang - ,
Qinghua Ji *- ,
Huaijia Xin - ,
Gong Zhang - ,
Xiaoyang Duan - ,
Shiyuan Deng - ,
Chengzhi Hu - ,
Huijuan Liu - , and
Jiuhui Qu *
Solar water evaporation (SWE) has emerged as an appealing method for water and salt recovery from hypersaline wastewater. However, different ions usually transfer and accumulate uncontrollably during ion–water separation, making salt fractionalization impractical for conventional SWE, and the resulting mixed salts are hard to use and still require significant costs for disposal. To achieve salt fractionalization and reutilization, achieving ion–water and ion–ion separation simultaneously are crucial in advancing SWE toward sustainability. Here, we present a wood-derived nanofluidic solar-driven fractional crystallizer that regulates the ion transfer processes and extracts nearly pure salt from a mixture of salts. SWE continuously induces capillary flow to propel and concentrate the ions in the wood channels. Meanwhile, engineered functional groups on the channel walls dominate the ion separation process via differentiated interactions with different ions. During ion transfer through channels, SO42– approaches the channel wall to compete for the positive charges and propels Cl– away, slowing SO42– transport and enlarging the transport energy barrier gap (2.65 to 19.28 kJ mol–1) between SO42– and Cl–. Through in situ observation, positive charges on the channel wall make SO42– lag Cl– 12.4 times that of bare Wood-D, accounting for the enhanced ion separation and the consequent fractional salt crystallization.
Highly Elastic Spongelike Hydrogels for Impedance-Based Multimodal Sensing
Xiangyu Duan - ,
Yongzhen Mi - ,
Tingyu Lei - ,
Xiu Yun Daphne Ma - ,
Zhong Chen - ,
Junhua Kong *- , and
Xuehong Lu *
Hydrogel-based sensors have been widely studied for perceiving the environment. However, the simplest type of resistive sensors still lacks sensitivity to localized strain and other extractable data. Enhancing their sensitivity and expanding their functionality to perceive multiple stimuli simultaneously are highly beneficial yet require optimal material design and proper testing methods. Herein, we report a highly elastic, sponge-like hydrogel and its derived multimodal iontronic sensor. By unidirectional freeze casting of poly(vinyl alcohol) (PVA) with electrospun cellulose nanofibers (CNF), a hierarchical structure with aligned PVA channels supported by interlaced CNF tangles is created. The structure ensures both efficient mass transport and good elasticity, enhancing reversible compressibility and ionic conductivity. Combining this sponge hydrogel with impedance-based measurement methods allows the development of multimodal sensors capable of detecting local strain, position, and material type of object-in-contact. Integrating these sensing capabilities, a two-dimensional small motion monitor, a 3D input interface, and a material identification gripper are demonstrated. This study provides a simple approach to versatile multimodal sensors.
January 3, 2025
Heteropolyacid Ligands in Two-Dimensional Channels Enable Lithium Separation from Monovalent Cations
Xinyao Dong - ,
Xinyu Ai - ,
Weijun He - ,
Yeming Zhai - ,
Ruixiang Guo - ,
Yi-Wei Li - ,
Zhu-Qing Ma - ,
Yang Yang *- , and
Kai-Ge Zhou *
Extracting lithium from salt lakes requires ion-selective membranes with customizable nanochannels. However, it remains a major challenge to separate alkali cations due to their same valences and similar ionic radius. Inspired by the K+ channel of KcsA K+, significant progress has been made in adjusting nanochannel size to control the ion selectivity dominated by alkali cations dehydration. Besides, several works involved incorporating ligands, such as crown ether, into nanochannels based on coordination chemistry to try to promote alkali cation selectivity; nevertheless, only the separation between mono-/bivalent cations has been achieved. Herein, a series of heteropolyacid (HPA) ligands are designed to functionalize two-dimensional (2D) nanochannels, achieving superior lithium perm-selectivity over other alkali cations (16 for Li+/K+), with the Li+ permeation rate increased to four times that of the pristine 2D membrane. We discover that the switching of an ion between its hydration and ion-HPA coordination states elucidates ion-selective transport, and the relatively lower depth of energy well for the exchange from Li+ hydration to Li+-HPA coordination results in the separation of Li+ from other alkali cations. This work demonstrates a principle for exploring novel ligands to develop alkali cation-selective membranes, expanding the potential applications of ion separation membranes in lithium extraction from aquatic sources.
Terahertz Wave Desensitizes Ferroptosis by Inhibiting the Binding of Ferric Ions to the Transferrin
Xiangji Li - ,
Yangmei Li - ,
Junxuan Xu - ,
Xinlian Lu - ,
Shixiang Ma - ,
Lan Sun *- ,
Chao Chang *- ,
Li Min *- , and
Chunhai Fan
Ferroptosis is a classic type of programmed cell death characterized by iron dependence, which is closely associated with many diseases such as cancer, intestinal ischemic diseases, and nervous system diseases. Transferrin (Tf) is responsible for ferric-ion delivery owing to its natural Fe3+ binding ability and plays a crucial role in ferroptosis. However, Tf is not considered as a classic druggable target for ferroptosis-associated diseases since systemic perturbation of Tf would dramatically disrupt blood iron homeostasis. Here, we reported a nonpharmaceutical, noninvasive, and Tf-targeted electromagnetic intervention technique capable of desensitizing ferroptosis with directivity. First, we revealed that the THz radiation had the ability to significantly decrease binding affinity between the Fe3+ and Tf via molecular dynamics simulations, and the modulation was strongly wavelength-dependent. This result provides theoretical feasibility for the THz modulation-based ferroptosis intervention. Subsequent extracellular and cellular chromogenic activity assays indicated that the THz field at 8.7 μm (i.e., 34.5 THz) inhibited the most Fe3+ bound to the Tf, and the wavelength was in good agreement with the simulated one. Then, functional assays demonstrated that levels of intracellular Fe2+, lipid peroxidation, malondialdehyde (MDA) and cell death were all significantly reduced in cells treated with this 34.5 THz wave. Furthermore, the iron deposition, lipid peroxidation, and MDA in the ferroptosis disease model induced by ischemia-reperfusion injury could be nearly eliminated by the same radiation, validating THz wave-induced desensitization of ferroptosis in vivo. Together, this work provides a preclinical exemplar for electromagnetic irradiation-stimulated desensitization of ferroptosis and predicts an innovative, THz wave-based therapeutic method for ferroptosis-associated diseases in the future.
January 2, 2025
Unveiling Trade-Off and Synergy in Simultaneous Removal of NOx, CO, and NH3 on Mixed Metal Oxide Nanostructure Catalysts
Wonsik Jang - ,
Myeung-Jin Lee - ,
Jongkyoung Kim - ,
Bora Jeong - ,
Seunghyun Lee - ,
Hyoseok Kim - ,
Xingyu Ding - ,
Kelvin H. L. Zhang - ,
Kwang Young Kim *- ,
Hong-Dae Kim *- , and
Seungho Cho *
The simultaneous removal reaction (SRR) is a pioneering approach for achieving the simultaneous removal of anthropogenic NOx and CO pollutants through catalytic reactions. To facilitate this removal across diverse industrial fields, it is crucial to understand the trade-offs and synergies among the multiple reactions involved in the SRR process. In this study, we developed mixed metal oxide nanostructures derived from layered double hydroxides as catalysts for the SRR, achieving high catalytic conversions of 93.4, 100, and 91.6% for NOx, CO, and NH3, respectively, at 225 °C. Furthermore, we elucidated the reaction mechanisms, revealing the trade-offs and synergies between the multiple reactions. In addition, we fabricated sheet-type catalysts and conducted SRR tests in a semibench-scale reactor with a gas flow rate of 10 L min–1 at 1% CO concentration. The fabricated catalysts exhibited high SRR activity and stability, even in the presence of SO2, highlighting their potential for practical applications.
Reconfigurable Sequential-Logic-in-Memory Implementation Utilizing Ferroelectric Field-Effect Transistors
Jingjie Niu - ,
Donggyu Kim - ,
Jie Li - ,
Jiahui Lyu - ,
Yoonmyung Lee *- , and
Sungjoo Lee *
This publication is Open Access under the license indicated. Learn More
In modern digital systems, sequential logic circuits store and process information over time, whereas combinational logic circuits process only the current inputs. Conventional sequential systems, however, are complex and energy-inefficient due to the separation of volatile and nonvolatile memory components. This study proposes a compact, nonvolatile, and reconfigurable van der Waals (vdW) ferroelectric field-effect transistor (FeFET)-based sequential logic-in-memory (S-LiM) unit that performs sequential logic operations in two nonvolatile states. Unlike conventional edge computing systems that require separate combinational logic circuits, sequential logic circuits (such as latches for short-term data storage), and nonvolatile memory for long-term data storage, this innovative S-LiM unit integrates logic and memory into a single nonvolatile vdW FeFET device. The nonvolatile ferroelectric elements directly replace both sequential logic and memory in conventional systems, eliminating frequent data transfers, reducing static power, and increasing the storage density. Six distinct logic operations are implemented in a single vdW FeFET through voltage-controlled ferroelectric polarization, highlighting the unit’s reconfigurability. The device shows significant potential for low-power edge computing, especially where frequent power cycling is necessary. Its nonvolatile polarization retains the state without the need for storing processes, enabling rapid recovery at startup, even after extended power-off periods of tens of minutes. These features make the vdW FeFET-based S-LiM unit ideal for energy-efficient, high-density, and low-power edge computing, especially in remote operations with unstable power supplies. This innovation contributes to the development of next-generation, low-power electronics with enhanced efficiency and storage density.
January 1, 2025
Resistive-Pulse Sensing Coupled with Fluorescence Lifetime Imaging Microscopy for Differentiation of Individual Liposomes
Tanner W. Young - ,
Sarah J. Cox-Vázquez - ,
Ethan D. Call - ,
Dhari C. Shah - ,
Stephen C. Jacobson *- , and
Ricardo J. Vázquez *
Characterization of individual biological nanoparticles can be significantly improved by coupling complementary analytical methods. Here, we combine resistive-pulse sensing (RPS) with fluorescence lifetime imaging microscopy (FLIM) to differentiate liposomes at the single-particle level. RPS measures the particle volume, shape, and surface-charge density, and FLIM determines the fluorescence lifetime of the fluorophore associated with the lipid membrane. The RPS devices are fabricated in-plane on a glass substrate to facilitate coupling of RPS with FLIM measurements. For proof-of-concept, we studied liposomes containing various cholesterol concentrations with membrane-intercalated Di-8-ANEPPS, whose fluorescence lifetime is known to be sensitive to cholesterol concentrations in the membrane. RPS-FLIM revealed that increasing cholesterol concentrations in the liposome from 0% to 50% increased the fluorescence lifetimes from 2.1 ± 0.2 to 3.4 ± 0.5 ns, respectively. Moreover, RPS-FLIM discerned liposome populations with the same cholesterol concentration but labeled with dyes that have different fluorescence lifetimes (Di-8-ANEPPS and COE-S6), parsing two particle populations with statistically identical volumes, cholesterol concentration, and lipid composition. Interrogation with RPS-FLIM occurred with individual particles making a single pass through the detection region and overcomes issues with fluorescence spectral overlap that limits traditional methods. We envision RPS-FLIM as a versatile and scalable technique with the potential to differentiate biological particles at the single-particle level to simultaneously inform on particle size, surface-charge density, membrane composition, and identity.
December 31, 2024
Reprogramming Dysfunctional Dendritic Cells by a Versatile Catalytic Dual Oxide Antigen-Captured Nanosponge for Remotely Enhancing Lung Metastasis Immunotherapy
Min-Ren Chiang - ,
Chin-Wei Hsu - ,
Wan-Chi Pan - ,
Ngoc-Tri Tran - ,
Yu-Sheng Lee - ,
Wen-Hsuan Chiang - ,
Yu-Chen Liu - ,
Ya-Wen Chen - ,
Shih-Hwa Chiou - , and
Shang-Hsiu Hu *
This publication is Open Access under the license indicated. Learn More
Dendritic cells (DCs) play a crucial role in initiating antitumor immune responses. However, in the tumor environment, dendritic cells often exhibit impaired antigen presentation and adopt an immunosuppressive phenotype, which hinders their function and reduces their ability to efficiently present antigens. Here, a dual catalytic oxide nanosponge (DON) doubling as a remotely boosted catalyst and an inducer of programming DCs to program immune therapy is reported. Intravenous delivery of DON enhances tumor accumulation via the marginated target. At the tumor site, DON incorporates cerium oxide nanozyme (CeO2)-coated iron oxide nanocubes as a peroxide mimicry in cancer cells, promoting sustained ROS generation and depleting intracellular glutathione, i.e., chemodynamic therapy (CDT). Upon high-frequency magnetic field (HFMF) irradiation, CDT accelerates the decomposition of H2O2 and the subsequent production of more reactive oxygen species, known as Kelvin’s force laws, which promote the cycle between Fe3+/Fe2+ and Ce3+/Ce4+ in a sustainable active surface. HFMF-boosted catalytic DON promotes tumors to release tumor-associated antigens, including neoantigens and damage-associated molecular patterns. Then, the porous DON acts as an antigen transporter to deliver autologous tumor-associated antigens to program DCs, resulting in sustained immune stimulation. Catalytic DON combined with the immune checkpoint inhibitor (anti-PD1) in lung metastases suppresses tumors and improves survival over 40 days.
Multispectral Integrated Black Arsenene Phototransistors for High-Resolution Imaging and Enhanced Secure Communication
Li Han - ,
Shi Zhang - ,
Shijian Tian - ,
Libo Zhang *- ,
Yingdong Wei - ,
Kaixuan Zhang - ,
Mengjie Jiang - ,
Yuan He - ,
Changlong Liu - ,
Weiwei Tang - ,
Jiale He - ,
Haibo Shu *- ,
Antonio Politano *- ,
Xiaoshuang Chen - , and
Lin Wang *
The demand for broadband, room-temperature infrared, and terahertz (THz) detectors is rapidly increasing owing to crucial applications in telecommunications, security screening, nondestructive testing, and medical diagnostics. Current photodetectors face significant challenges, including high intrinsic dark currents and the necessity for cryogenic cooling, which limit their effectiveness in detecting low-energy photons. Here, we introduce a high-performance ultrabroadband photodetector operating at room temperature based on two-dimensional black arsenene (b-As) nanosheets. This device demonstrates responsivity across visible, near-infrared, and THz spectral ranges, with responsivities reaching 91.6 A/W at 520 nm, 6.3 A/W at 1550 nm, and 7.8 V/W at 0.27 THz. The exceptional THz responsivity is attributed to the use of plasma-wave rectification in antenna-integrated field-effect transistors with asymmetric antennas, enhancing light-matter interaction and facilitating nonlinear rectification within the two-dimensional electron gas of the transistor channel, achieving a voltage-dependent bipolar response. These advanced b-As-based photodetectors also enable secure THz communication through complex logic operations, achieving robust data encryption and high-performance signal processing.
December 30, 2024
Opportunities in Bottlebrush Block Copolymers for Advanced Materials
Dipankar Saha - ,
Connor L. Witt - ,
Rida Fatima - ,
Takumi Uchiyama - ,
Varun Pande - ,
Dong-Po Song *- ,
Hua-Feng Fei *- ,
Benjamin M. Yavitt *- , and
James J. Watkins *
Bottlebrush block copolymers (BBCPs) are a unique class of materials that contain a backbone with densely grafted and chemically distinct polymeric side chains. The nonlinear architecture of BBCPs provides numerous degrees of freedom in their preparation, including control over key parameters such as grafting density, side chain length, block arrangement, and overall molecular weight. This uniquely branched structure provides BBCPs with several important distinctions from their linear counterparts, including sterically induced side chain and backbone conformations, rapid and large self-assembled nanostructures, and reduced or eliminated entanglement effects (assuming sufficient grafting density and that the molecular weight of the side chains is below their respective entanglement molecular weight). These distinctions allow access to large domain sizes, very rapid assembly, and the ability to preferentially add additives and/or precursors to one domain, thereby enabling the efficient fabrication of a wide range of advanced materials and devices. BBCPs have been utilized to create finely controlled and well-ordered nanostructures for use in applications, such as photonic crystals, drug delivery systems, energy conversion, energy storage devices, and key components in surface coatings. To further deploy BBCPs as templates for the formation of precise nanostructures, having a thorough understanding of their synthesis, self-assembly, and templating is necessary. To explore and understand the self-assembly and subsequent applications of BBCPs, this review emphasizes the physics of self-assembly for BBCPs (including architectural, rheological, and thermodynamic considerations) and structure–property relationships between BBCPs and their resulting nanostructures. Lastly, we provide an overview of current research trends using BBCPs in energy storage, energy conversion, photonic, 3D printing, and drug delivery applications. We aim to provide researchers with the fundamentals of BBCP self-assembly in their use as nanostructured materials to continue their development of advanced materials.
December 26, 2024
Understanding the Formation Dynamics and Physical Properties of Nanocapsules Using Charge Detection Mass Spectrometry
Conner C. Harper - ,
Tracy H. Schloemer - ,
Jacob S. Jordan - ,
Nicole Heflin - ,
Pournima Narayanan - ,
Qi Zhou - ,
Daniel N. Congreve *- , and
Evan R. Williams *
Characterizing the size, structure, and composition of nanoparticles is vital in predicting and understanding their macroscopic properties. In this work, charge detection mass spectrometry (CDMS) was used to analyze nanocapsules (∼10–200 MDa) consisting of a liquid oleic acid core surrounded by a dense silica outer shell. CDMS is an emerging method for nanoparticle analysis that can rapidly measure the mass and charge of thousands of individual nanoparticles. We find that increasing the feed volume of the tetraethylorthosilicate (TEOS) precursor added to form the silica shell of the nanocapsules yielded both higher and broader nanocapsule mass distributions with differentiable densities. A two-dimensional mass versus charge analysis also revealed the formation of two distinct populations of nanocapsules. These two nanocapsule morphologies were also present in transmission electron microscopy (TEM) images and exhibited low-density spherical cores and crescent-shaped cores where the remainder of the core volume was “filled in” by more dense silica. Nanocapsule shell growth kinetics over a ∼48-h synthesis period were also monitored by sampling the reaction mixture at various times, quenching the sampled aliquots, and then characterizing these time-resolved samples by CDMS. The CDMS data reveal three distinct growth phases in nanocapsule formation; rapid initial nucleation, an “inverted” distribution of silica growth, and a final slow growth phase where the rate of mass increase and final nanocapsule masses are dictated by the initial TEOS feed volumes. CDMS-enabled understanding of the diverse nanocapsule sizes, morphologies, and growth dynamics will allow us to better predict nanocapsule properties while reducing the experimental burden in optimizing nanocapsules for real-world applications.
Nitric Oxide-Releasing Mesoporous Hollow Cerium Oxide Nanozyme-Based Hydrogel Synergizes with Neural Stem Cell for Spinal Cord Injury Repair
Dun Liu - ,
Runyan Niu - ,
Siliang Wang - ,
Lihua Shao - ,
Xian Yang - ,
Xuexue Liu - ,
Xiaolong Ma - ,
Zezhang Zhu - ,
Jinping Zhang *- ,
Benlong Shi *- ,
Huanyu Ni *- , and
Xiao Du *
Neural stem cell (NSCs) transplantation is a promising therapeutic strategy for spinal cord injury (SCI), but its efficacy is greatly limited by the local inhibitory microenvironment. In this study, based on l-arginine (l-Arg)-loaded mesoporous hollow cerium oxide (AhCeO2) nanospheres, we constructed an injectable composite hydrogel (AhCeO2-Gel) with microenvironment modulation capability. AhCeO2-Gel protected NSCs from oxidative damage by eliminating excess reactive oxygen species while continuously delivering Nitric Oxide to the lesion of SCI in a pathological microenvironment, the latter of which effectively promoted the neural differentiation of NSCs. The process was confirmed to be closely related to the up-regulation of the cAMP-PKA pathway after NO-induced calcium ion influx. In addition, AhCeO2-Gel significantly promoted the polarization of microglia toward the M2 subtype as well as enhanced the regeneration of spinal nerves and myelinated axons. The prepared bioactive hydrogel system also efficiently facilitated the integration of transplanted NSCs with host neural circuits, replenished damaged neurons, alleviated neuroinflammation, and inhibited glial scar formation, thus significantly accelerating the recovery of motor function in SCI rats. Therefore, AhCeO2-Gel synergized with NSCs transplantation has great potential as an integrated therapeutic strategy to treat SCI by comprehensively reversing the inhibitory microenvironment.
December 23, 2024
Water, Solute, and Ion Transport in De Novo-Designed Membrane Protein Channels
Yuhao Li - ,
Bradley S. Harris - ,
Zhongwu Li - ,
Chenyang Shi - ,
Jobaer Abdullah - ,
Sagardip Majumder - ,
Samuel Berhanu - ,
Anastassia A. Vorobieva - ,
Sydney K. Myers - ,
Jeevapani Hettige - ,
Marcel D. Baer *- ,
James J. De Yoreo *- ,
David Baker *- , and
Aleksandr Noy *
Biological organisms engineer peptide sequences to fold into membrane pore proteins capable of performing a wide variety of transport functions. Synthetic de novo-designed membrane pores can mimic this approach to achieve a potentially even larger set of functions. Here we explore water, solute, and ion transport in three de novo designed β-barrel membrane channels in the 5–10 Å pore size range. We show that these proteins form passive membrane pores with high water transport efficiencies and size rejection characteristics consistent with the pore size encoded in the protein structure. Ion conductance and ion selectivity measurements also show trends consistent with the pore size, with the two larger pores showing weak cation selectivity. MD simulations of water and ion transport and solute size exclusion are consistent with the experimental trends and provide further insights into structure–function correlations in these membrane pores.