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Mechanical Stimulation and Aligned Poly(ε-caprolactone)–Gelatin Electrospun Scaffolds Promote Skeletal Muscle Regeneration
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  • Francisco José Calero-Castro*
    Francisco José Calero-Castro
    Department of General and Digestive Surgery, “Virgen del Rocío” University Hospital/IBiS/CSIC/University of Seville, 41013 Seville, Spain
    Oncology Surgery, Cell Therapy, and Organ Transplantation Group. Institute of Biomedicine of Seville (IBiS), “Virgen del Rocío” University Hospital, IBiS, CSIC/University of Seville, 41013 Sevilla, Spain
    *Email: [email protected]; [email protected]
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    Orcidhttps://orcid.org/0000-0002-6039-3091
  • Víctor Manuel Perez-Puyana
    Víctor Manuel Perez-Puyana
    Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, 41012 Sevilla, Spain
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    Orcidhttps://orcid.org/0000-0001-5309-9647
  • Imán Laga
    Imán Laga
    Department of General and Digestive Surgery, “Virgen del Rocío” University Hospital/IBiS/CSIC/University of Seville, 41013 Seville, Spain
    Oncology Surgery, Cell Therapy, and Organ Transplantation Group. Institute of Biomedicine of Seville (IBiS), “Virgen del Rocío” University Hospital, IBiS, CSIC/University of Seville, 41013 Sevilla, Spain
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  • Javier Padillo Ruiz
    Javier Padillo Ruiz
    Department of General and Digestive Surgery, “Virgen del Rocío” University Hospital/IBiS/CSIC/University of Seville, 41013 Seville, Spain
    Oncology Surgery, Cell Therapy, and Organ Transplantation Group. Institute of Biomedicine of Seville (IBiS), “Virgen del Rocío” University Hospital, IBiS, CSIC/University of Seville, 41013 Sevilla, Spain
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  • Alberto Romero*
    Alberto Romero
    Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, 41012 Sevilla, Spain
    *Email: [email protected]
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  • Fernando de la Portilla de Juan
    Fernando de la Portilla de Juan
    Department of General and Digestive Surgery, “Virgen del Rocío” University Hospital/IBiS/CSIC/University of Seville, 41013 Seville, Spain
    Oncology Surgery, Cell Therapy, and Organ Transplantation Group. Institute of Biomedicine of Seville (IBiS), “Virgen del Rocío” University Hospital, IBiS, CSIC/University of Seville, 41013 Sevilla, Spain
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ACS Applied Bio Materials

Cite this: ACS Appl. Bio Mater. 2024, 7, 10, 6430–6440
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https://doi.org/10.1021/acsabm.4c00559
Published October 4, 2024

Copyright © 2024 The Authors. Published by American Chemical Society. This publication is licensed under

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Abstract

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The current treatments to restore skeletal muscle defects present several injuries. The creation of scaffolds and implant that allow the regeneration of this tissue is a solution that is reaching the researchers’ interest. To achieve this, electrospinning is a useful technique to manufacture scaffolds with nanofibers with different orientation. In this work, polycaprolactone and gelatin solutions were tested to fabricate electrospun scaffolds with two degrees of alignment between their fibers: random and aligned. These scaffolds can be seeded with myoblast C2C12 and then stimulated with a mechanical bioreactor that mimics the physiological conditions of the tissue. Cell viability as well as cytoskeletal morphology and functionality was measured. Myotubes in aligned scaffolds (9.84 ± 1.15 μm) were thinner than in random scaffolds (11.55 ± 3.39 μm; P = 0.001). Mechanical stimulation increased the width of myotubes (12.92 ± 3.29 μm; P < 0.001), nuclear fusion (95.73 ± 1.05%; P = 0.004), and actin density (80.13 ± 13.52%; P = 0.017) in aligned scaffolds regarding the control. Moreover, both scaffolds showed high myotube contractility, which was increased in mechanically stimulated aligned scaffolds. These scaffolds were also electrostimulated at different frequencies and they showed promising results. In general, mechanically stimulated aligned scaffolds allow the regeneration of skeletal muscle, increasing viability, fiber thickness, alignment, nuclear fusion, nuclear differentiation, and functionality.

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Introduction

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Skeletal muscle represents about 40% to 50% of the total weight of the human being and contributes significantly to several bodily functions. Its main function is the transformation of chemical energy into mechanical energy. (1) This tissue can self-repair and regenerate in response to any injury or damage. However, when muscle loss exceeds 20% and the lesion is several, also known as volumetric muscle loss (VML), regeneration is not possible. (2,3) Currently, the conventional strategy of care for VML is to use autologous muscle grafts. However, this treatment has different limitations, such as tissue availability, the grafted muscle flap does not restore lost functionality, postoperative infection, scar tissue formation, and donor site morbidity. (4) This is the reason why researchers have increased their interest in the field of tissue regeneration.
Tissue engineering (TE) emerges as a promising approach for the development of novel strategies to repair VML by mimicking the properties of native tissue. (5) This field uses stem cells, biomaterial scaffolds, and bioactive molecules to engineer functional tissue. The use of scaffold-associating cells mimics the tissue environment and the factors that stimulate the cells in their proliferation and differentiation. (6)
One of the most promising techniques for the creation of scaffolds is electrospinning. This approach lets us get scaffolds with a fibrillar conformation that improves the regeneration of different tissues (7) such as tendon regeneration, (8) cartilage repair (9) or cardiac TE, (9) and different medical applications. This technique has attracted the interest of many researchers due to its ability to create 3D porous nanofibrous scaffolds with properties similar to those of human tissue and the native extracellular matrix (ECM) network at the nanoscale level. (10) Electrospun structures present a very high surface area, making these structures a suitable candidate for cell adhesion, proliferation, and differentiation, which is essential to guide tissue formation. (11) Several parameters can be adjusted during electrospinning. Fiber thickness and fiber morphology can be modified by varying different electrospinning parameters such as the type of polymer, the nature of the solvent, the applied voltage, and the distance between the syringe tip and the type of collector. (10) For example, a rotating type collector allows obtaining aligned nanofibers, while the static type collector favors the generation of random nanofibers. (7) It has been demonstrated that the rotational speed of the collector had a considerable impact on the anisotropy of the resulting fiber mesh, which in turn influenced the mechanical properties of the scaffolds and the orientation and rearrangement of the nanofibers. (12) Choi et al. (13) compared the influence of unidirectional fiber orientation with nonoriented fibers. They showed that scaffolds with a unidirectional fiber orientation play a role in cell orientation and enhance myotube formation. Different works demonstrated that the alignment of fibers in these scaffolds favors cytoskeleton reorganization in myoblasts in skeletal muscle regeneration. (13−16)
Poly(ε-caprolactone) (PCL) is one of the most widely used biodegradable polymers in electrospinning and was approved by the FDA for use in various biomedical applications ranging from drug delivery to implantable devices. (17) However, PCL has some drawbacks, such as its hydrophobicity and low degradation rate, which limit its cellular interaction and postimplantation resorption, respectively. Therefore, it has been used in combination with other materials to improve its biological and mechanical properties. (18−21) One of these materials that has been combined with PCL is gelatin, which is a denatured, hydrolyzed form of collagen obtained by hydrolyzing collagen protein fibrils through physical and chemical methods. Gelatin has been used in various forms and blends for the manufacture of scaffolds (22) for TE applications due to its biodegradability, biocompatibility, and simple processing properties. (23) Finally, there are different studies that demonstrate that the combination of 4% gelatin and 16% PCL is ideal for use in the creation of scaffolds since it creates more deformable, less rigid, and more hydrophilic structures, favoring greater cell adhesion. (24,25)
Another important element of TE is the use of bioreactors with stimulation to recreate the physiology of the tissue that can distribute the cells homogeneously and increase cell proliferation, maturation, differentiation, and functionalization. (26) Many works have described improved tissue functionality and differentiation when scaffolds are exposed to mechanical stimulation, (27,28) increasing actin and myosin expression, (29,30) as well as diameter and length of mature skeletal muscle fibers. (31) Several studies have shown a pattern of mechanical stimulation in which crops were subjected to a stress load that increased over time. In addition, these loads were accompanied by rest. (32−34) Studies using mechanical stimulation for tissue-engineered skeletal muscle structures have demonstrated improvements in differentiation, maturation, alignment, and contractility of tissue-engineered muscle. (3)
Our previous work demonstrated good behavior of PCL and gelatin scaffolds, (24) supporting this project that aims to combine these scaffolds with mechanical stimulation in a bioreactor. Here, we hypothesize that electrospun scaffolds of PCL with gelatin, along with their stimulation in a mechanical bioreactor, could improve the creation of skeletal muscle tissue. This project aims to regenerate skeletal muscle using PCL/gelatin electrospun scaffolds and mechanical stimulation. To demonstrate this, we measured the viability, morphology, cytoskeleton, and functionality of the myotubes.

Materials and Methods

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Fabrication of Scaffolds

Electrospun scaffolds were fabricated using a binary solution based on PCL (Sigma-Aldrich, Germany) in 16% yield and type B gelatin protein (80–120 gBloom, Henan Boom Gelatin Co., Ltd., China) in a 4% yield. The electrospinning process was carried out with electrospinning equipment Fluidnatek LE-50 (Bioinicia, Valencia, Spain) (Figure 1). The process was conducted in vertical mode with the following conditions: 14 kV, 0.4 mL h-1, 14 cm gap, and 40% environmental humidity (an 18G stainless steel needle was used). Two different scaffolds were processed by changing the rotational speed of the collector, obtaining scaffolds with a random fiber orientation (with no rotational speed) and scaffolds with an aligned fiber orientation (with a rotational speed higher than 500 rpm). The scaffolds fabricated presented a circular shape with an 18 mm diameter and 10–15 μm thickness.

Figure 1

Figure 1. (a) Schematic image of the electrospinning setup. (b) Mechanical bioreactor with electrospun scaffolds. (c,d) Software setup for mechanical stimulation.

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Characterization of Scaffolds

SEM Imaging

The microscopic examination of the scaffolds was performed using a Zeiss EVO scanning electron microscope (Germany) with a secondary electron detector at an acceleration voltage of 10 kV. SEM images were obtained at two different magnifications (1000× and 4000×). A digital processing free software (ImageJ) was used to determine the mean fiber size of the nanostructures.

Contact Angle Measurements

Scaffold wettability was obtained by water contact angle measurements using a Drop Shape Analyzer (Germany). It was calculated as the mean value of the right and left sides of a 5 μL deionized water drop after 5 s of stability after droplet deposition.

Mechanical Properties

The static tensile test of the nanofibrous membranes was carried out on a RSA3 rheometer (TA Instruments, USA). Tensile tests were carried out at 1 mm/min on samples with a rectangular shape. From each test, the different parameters, including the maximum stress, strain at break, and Young’s modulus, were calculated.

Cell Culture

The C2C12 skeletal muscle cell line (ATCC CRL-1458) was used for the cell culture. The cells were cultured in a growth medium (GM) composed of Dulbecco’s modified Eagle medium (DMEM)/high glucose (SH30285.01, HyClone) supplemented with 10% FBS (F7524, Sigma-Aldrich) and 1% penicillin–streptomycin (15140-122, Gibco) at 37 °C in an atmosphere of 5% CO2 until they reached a confluence of 70–80%. The cells were split by using 0.05% trypsin/EDTA (25300-062, Gibco) for subsequent seeding on the scaffolds. The myoblasts were seeded on the scaffolds in a cell concentration of 10 × 106 cells per scaffold based on previous results of our group. (25) The scaffolds were cultured on a 6-well plate with the GM at 37 °C in an atmosphere of 5% CO2 and they were cultured for 2 weeks. After 4 days of seeding, the GM was replaced by the differentiation medium (DM) DMEM/high glucose supplemented with 2% FBS and 1% penicillin–streptomycin. The medium was regularly replaced every 48 h.

Mechanical Stimulation in a Bioreactor

Random and aligned scaffolds were cultured with mechanical tensile stimulation after 48 h from scaffold seeding with the TC3 bioreactor (EBERS Medical Technology SL, Zaragoza, Spain) for 2 weeks in an incubator at 37 °C in an atmosphere of 5% CO2 (Figure 1b) in the same conditions, 4 days with the GM and with the DM up to 2 weeks after seeding. Briefly, the scaffolds are placed between two grips in order to fix the tissue sample to the chambers; one of them was fixed and the other one was moving, applying the stimulation to the scaffolds. The stimulation was controlled by the EBERS software of the bioreactor (Figure 1c,d). The amplitude varied over the 2 weeks of culture: 5% amplitude of the scaffold long (0.9 mm) during week 1, followed by mechanical stimulation with 10% amplitude (1.8 mm) during week 2. The scaffolds were stimulated for 55 and 5 min of rest in relaxation at a frequency of 0.5 Hz for 2 weeks based on previous works. (3)

Viability

The cell viability was measured on day 14 using a live/dead cell viability kit (consisting of calcein/ethidium (EthD-1); LIVE/DEAD Viability/Cytotoxicity Kit, Invitrogen). The medium was removed, and the scaffolds were washed with PBS. We diluted EthD-1 2 mM and calcein AM 4 mM solution in PBS to get a dilution of 4 and 2 μM, respectively, and shook to homogenize the reagent. We stained each scaffold with 200 μL of the prepared solution and incubated it for 30 min. We visualized the cells using a Nikon A1R+ confocal microscope with a 488 nm laser at a 10× magnification and at least 5 images per scaffold were taken. Live cells were counted as green cytoplasmic, while dead cells were counted as red-stained nuclei using ImageJ. To count confluent cells, we used the watershed algorithm. The viability was defined as the ratio between the number of viable cells and total cell number (viable cells and dead cells).

Immunofluorescence

After 2 weeks of seeding, the scaffolds were washed with PBS at least three times. We fixed the scaffolds for 15 min with paraformaldehyde and then the scaffolds were washed with PBS three times again. Subsequently, the cells were permeabilized with 0.5% Triton in PBS for 5 min, the supernatant was removed, and a blocking solution (BS; 1% bovine serum albumin, 0.1% Tween 20 in PBS) was applied for 10 min. The scaffolds were stained with Phalloidin-iFluor 647 Reagent (ab176759, Abcam, Cambridge, UK) at a concentration of 1:1000 in the BS for 1 h in a humid dark chamber with shaking at room temperature. After that, we removed and washed with BS for 2 min three times. We mounted the scaffolds on slides and added a mounting medium with DAPI (ProLong, Thermo Fisher, Waltham, Massachusetts, USA). The stained nuclei and actin of the formed cytoskeleton were visualized using a Nikon A1R + confocal microscope with 405 and 638 nm, respectively, and at least 5 images were taken per scaffold at 10× magnification and at 40× magnification. The images were analyzed with ImageJ. To measure the cell alignment, images with 10× magnification and the orientation plugin were used. Myotube orientation was calculated as % of myotubes with an orientation between −10° and 10° over the total number of myotubes in the scaffold. The fiber thickness was measured using the straight command, each fiber was measured in 5 different points, and at least 20 fibers were measured per scaffold. The fusion rate was defined as the number of nuclei possessed by the fibers over the total nuclei, and the 40× magnification images were used. The nucleus morphology (measured by circularity and aspect ratio in ImageJ) was measured using 40× magnification images. The formula for circularity is 4 x π x area/perimeter2 and the aspect ratio was defined as the ratio between the length of the longest line and the length of the shortest line across the nuclei.

Functionality Assay

Cells were stained with the Fluo-4 AM kit (Invitrogen TM, Waltham, Massachusetts, USA) to measure the functionality and contractile capacity of the cultured scaffolds. The reagent was used in a 1–5 μM concentration diluted in a culture medium. The scaffolds were incubated with the solution for 20 min until the assay. Two buffer solutions were required, one as a control, characterized by a low potassium solution, and another with high potassium levels that stimulate cell contraction. Both solutions were composed of calcium chloride (C1016, Sigma-Aldrich, St. Louis, USA) at 2.5 mM, magnesium chloride (M8266, Sigma-Aldrich, St. Louis, USA) at 2 mM, HEPES (A3724, Panreac Química, Spain) at 10 mM, and glucose (G8270, Sigma-Aldrich, St. Louis, USA) at 10 mM. Both differed in sodium chloride (S9888, Sigma-Aldrich, St. Louis, USA) at 140 and 30 mM, in the control and high potassium solution, respectively, and in potassium chloride (P3911, Sigma-Aldrich, St. Louis, USA) at 2.5 and 110 mM, in the control and high potassium solution, respectively. The solutions were adjusted to pH 7.4. During the study, two syringes were used, one with each solution. Each syringe has a stopcock; the one with the control solution was always open during the whole experiment, while the one with the high potassium solution was opened at specific times to evaluate the cellular response to the stimulus. Each scaffold was stimulated at least twice. The level of luminescence varies as calcium enters the cells due to the influence of the high potassium solution; calcium binds to Fluo-4 and causes luminescence peaks. The high potassium solution can prevent the outflow of potassium, which depolarizes the cell and forces the opening of calcium channels. The 10× magnification of the Nikon A1R+ confocal microscope with a 488 nm laser was used for this study. Finally, we measure the luminescence cell as a function of time. The luminescence increase, which was defined as the difference in luminescence between the peak of the stimulus and the mean luminescence of the cell at rest, was measured, and the luminescence difference was defined as the difference between the first and second peaks of the stimulus. Both the luminescence increase and the luminescence difference between the peaks of each stimulus are dimensionless variables.

Electrical Stimulation

The scaffolds that presented a high response to high potassium solution were electrically stimulated with the TC3 bioreactor signal generator (EBERS Medical Technology SL, Zaragoza, Spain) at different frequencies and visualized under confocal microscopy with Fluo-4 staining. The frequencies picked up were 0.2, 0.5, 1, 1.5, and 2 Hz.

Statistics

Quantitative variables were summarized by the mean and standard deviation. Sample normality was also calculated by the Shapiro–Wilk test if n < 50 or Kolmogorov–Smirnov test if n > 50. For quantitative variables, the Mann–Whitney U test was used when the samples did not show a normal distribution. For quantitative variables that showed a normal distribution, the Student’s t-test was used. For the comparison of more than two samples with a normal distribution, the analysis of variance (ANOVA) test was used for independent measures, and the Kruskal–Wallis test when there was no normal distribution. The ANOVA test was used for quantitative variables when the independent variable offered more than two values, using Tukey’s test if differences were found and the variances were equal. In the case where the variances were different, Tamhane’s test was used. For the pairwise analysis of the samples that did not have a normal distribution, the Mann–Whitney U test was used. A P < 0.05 was established as statistically significant; significant: 0.01 < P < 0.05; very significant: 0.001 < P < 0.01, and extremely significant: P < 0.001. The IBM SPSS Statistics 19 package was used for statistical analysis. GraphPad Prism 9 and OriginPro 2022 software were used for the graphs.

Results

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Characterization of the Scaffolds

SEM images of the obtained scaffolds at different magnifications are shown in Figure 1. The different orientations obtained can be seen for both systems, from the randomly oriented system (Figure 2b,c) with fibers without a predefined orientation and from the aligned system (Figure 2d,e) with a predefined orientation toward the X axis. A summary of the properties of the obtained scaffolds is shown in Table 1. Water contact angle values obtained for both systems revealed a hydrophilic system with a higher wettability for the aligned system, as shown by a decrease in the contact angle (Figure 2a,b). Furthermore, the alignment of the fibers produced a system with a lower Young’s modulus and a lower deformability. On the other hand, comparing the mean fiber size (Table 1), higher fiber sizes were produced with a random orientation, although there are no significant differences between both systems.

Figure 2

Figure 2. Water contact angle of the nanofiber scaffolds with (A) random and (D) aligned orientation and SEM imaging at different magnifications (1000× and 4000×) of the nanofiber scaffold with a random (B,C, respectively) and aligned orientation (E,F, respectively).

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Table 1. Contact Angle, Mean Fiber Size (Width), Young’s Modulus, and Strain at Break of the Different Scaffolds
 random orientationaligned orientation
contact angle (°)51 ± 131 ± 2
mean fiber size (nm)320 ± 79205 ± 41
Young’s modulus (Pa)6.3·106 ± 1.5·1062.3·106 ± 0.4·106
strain at break (mm/mm)0.66 ± 0.050.31 ± 0.02

Viability

The random scaffolds (n = 3) had a viability of 86.54 ± 9.38% (Figure 3a), while that of the aligned scaffolds (n = 3) was 89.47 ± 8.35% (Figure 3b). When the scaffolds were mechanically stimulated, the random scaffolds (n = 3) had a viability of 86.19 ± 5.93% (Figure 3c), while aligned scaffolds (n = 3) increased the viability to 96.00 ± 3.13% (Figure 3d). No significant differences were found between random and aligned scaffolds without stimulation (P = 0.267) and between random and aligned scaffolds with mechanical stimulation (P = 0.064). Mechanical stimulation did not lead to significant differences in cell viability in random scaffolds (P = 0.398) or aligned scaffolds (P = 0.273) (Figure 3e).

Figure 3

Figure 3. Viability of electrospun scaffolds at day 14: control random scaffolds (a), control aligned scaffolds (b), mechanically stimulated random scaffolds (c), mechanically stimulated aligned scaffolds (d), and viability (e) (scale bar: 200 μm).

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Morphological Characterization

Figure 4 shows the immunostaining of myotubes created with the scaffolds. Figure 5 shows the distribution of the myotubes according to each type of scaffold and stimulation used (n = 3). In this way, we see how the fiber orientation undergoes greater ordering as the scaffold nanofibers increase their orientation. In addition, mechanical stimulation increases the fiber ordering in the aligned scaffolds. The fiber alignment of the random scaffolds (Figure 5a) was 21.44 ± 3.71%, while the aligned scaffolds presented an alignment of 49.51 ± 2.03% (Figure 5b). The mechanically stimulated random scaffolds (n = 3) showed a fiber alignment of 21.07 ± 4.76% (Figure 5c), whereas the fibers of the mechanically stimulated aligned scaffolds (n = 3) showed an alignment of 54.89 ± 1.63% (Figure 5d). Statistical difference (Figure 6a) was found between the alignment of the myotubes of the random and aligned scaffolds without stimulation (P < 0.001). A significant difference (Figure 6a) was demonstrated in the alignment of myotubes of random and mechanically stimulated aligned scaffolds (P < 0.001). Mechanical stimulation did not induce an increase in alignment within the random scaffolds (P = 0.700). However, in the aligned scaffolds, stimulation was shown to promote an increase in fiber alignment (P = 0.023).

Figure 4

Figure 4. Immunostaining of myotubes after day 14. Blue: nucleus. Red: actin. Control random scaffolds 10X (a), control random scaffolds 40X (b), control aligned scaffolds 10X (c), control aligned scaffolds 40X (d), mechanical stimulated random scaffolds 10X (e), mechanical stimulated random scaffolds 40X (f), mechanical stimulated aligned scaffolds 10X (g), and mechanical stimulated aligned scaffolds 40X (h).

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Figure 5

Figure 5. Myotube alignment at day 14. Control random scaffolds (a), control aligned scaffolds (b), mechanical stimulated random scaffolds (c), and mechanical stimulated aligned scaffolds (d).

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Figure 6

Figure 6. Analysis of myofibers at day 14. Actin fiber alignment (a), actin fiber width (b), fusion index (c), aspect ratio (d), and circularity (e).

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The thickness of the myotubes (Figure 6b) created with the random scaffolds (n = 3) was 11.55 ± 3.39 μm and that of the myotubes of the aligned scaffolds (n = 3) was 9.84 ± 1.15 μm. The existence of a significant difference between both groups was demonstrated (P = 0.006). The mechanically stimulated random scaffolds (n = 3) generated myotubes with a thickness of 19.21 ± 4.88 μm and the aligned scaffolds (n = 3) with a thickness of 12.92 ± 3.29 μm. A statistically significant difference between both groups (P < 0.001) was evidenced. In addition, it was demonstrated that mechanical stimulation increased the thickness of the myotubes in both random (P < 0.001) and aligned scaffolds (P < 0.001).
We analyzed the nucleus that were inside the fibers out of the total nucleus detected in each type of scaffold (n = 3). Thus, we found that in the random scaffolds, 80.73 ± 5.21% of the nucleus were inside the fibers, while in the aligned scaffolds, the density increased to 87.28 ± 2.22%. No significant difference was evident between the nuclear density of the 2 types of scaffolds (P = 0.116) (Figure 6c). As for the mechanically stimulated scaffolds, the random scaffolds presented a melting rate of 99.23 ± 0.89% and that of the aligned scaffolds was 95.73 ± 1.05%. There was a significant difference between both groups (P = 0.012). In addition, mechanical stimulation was found to increase the fusion index of both random (P = 0.004) and aligned scaffolds (P = 0.004).
To measure cell maturation, we used 2 parameters: nucleus aspect ratio (Figure 6d) and nucleus circularity (Figure 6e). Starting with random scaffolds (n = 3), these had a nucleus aspect ratio of 1.49 [1.30, 1.75] and a circularity of 0.59 [0.46, 0.74], while the aspect ratio was 1.76 [1.50, 2.10] in aligned scaffolds (n = 3) and circularity 0.65 [0.52, 0.75]. Significant differences were found between both groups in aspect ratio (P < 0.001) and circularity (P < 0.001). The myotube nucleus of the mechanically stimulated random scaffolds had an aspect ratio of 1.51 [1.29, 1.81] and a circularity of 0.62 [0.53, 0.72] and those of the aligned scaffolds had an aspect ratio of 1.60 [1.40, 1.88] and a circularity of 0.50 [0.39, 0.60]. Significant differences were evident between the aspect ratio (P < 0.001) and circularity (P < 0.001) of both scaffolds when stimulated. Finally, random scaffolds only showed a significant difference in circularity (P < 0.001) between the control group and the mechanically stimulated group. The aligned scaffolds presented significant differences in aspect ratio (P < 0.001) and circularity (P < 0.001).

Functionality Assay

The scaffolds (n = 3) were analyzed with a functionality assay. All groups showed cell functionality, although not all of it was due to the response to K+ ions or electrical stimulation, as shown in Figure 7, where luminescence normalized is represented. In random (Figure 7a), aligned (Figure 7b), and aligned mechanically stimulated (Figure 7d) scaffolds, some luminescence peaks can be observed approximately 1’5 min after the stimulus with high potassium solution.

Figure 7

Figure 7. Functionality assay measured by cellular luminescence due to calcium transients at day 14 after stimulation with high potassium solution. Control random scaffolds (a), control aligned scaffolds (b), mechanically stimulated random scaffolds (c), mechanically stimulated aligned scaffolds (d), and electrical stimulation of mechanical stimulated aligned scaffolds (e).

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In random scaffolds, the luminescence levels increased after the first stimulus of 34.75 ± 15.87 and the second stimulus of 15.01 ± 11.92. Therefore, the difference in luminescence levels is 19.74 ± 15.49. On the other hand, aligned scaffolds showed a luminescence increase of 22.37 ± 8.51 and 13.76 ± 9.26 after the first and second stimulus, respectively. The difference in luminescence between both peaks was 8.61 ± 1.54. Random and aligned scaffolds only showed significant differences related to the difference in luminescence between both peaks (P = 0.004), the luminescence after the first stimulus (P = 0. 083), and the luminescence after the second stimulus (P = 1.000).
The mechanically stimulated random scaffolds showed an increase in the luminescence of 25.89 ± 14.50. After the second stimulus, the increase in the luminescence was 15.37 ± 12.76. This low response may be due to the short exposure time or cell fatigue after the first stimulus. The difference in luminescence between both peaks was 10.53 ± 15.57. The mechanically stimulated aligned scaffolds showed an increase in luminescence of 30.41 ± 13.79. After the second stimulus, the increase in luminescence was 0.33 ± 3.23. This low response may be due to the short exposure time or the cell fatigue after the first stimulus. The difference in luminescence between both peaks was 30.73 ± 13.22. In mechanically stimulated scaffolds, there were significant differences in the increase in luminescence levels after the first (P = 0.010) and second (P = 0.001) stimulus, as well as in the difference between both of them (P = 0.001).
Mechanical stimulation in random scaffolds did not show a significant difference in the luminescence of the first stimulus (P = 0.136) as well as the second stimulus (P = 0.881), in the difference between both increases (P = 0.137).
Mechanical stimulation in aligned scaffolds showed a significant difference in the difference between both increases (P < 0.001). However, the luminescence of the first stimulus (P = 0.661) as well as the second stimulus (P = 0.054) did not show a significant difference.
Finally, since mechanically stimulated scaffolds showed evident contractility and fiber orientation, they were electrically stimulated to evaluate their response against this new stimulus (S1). As shown in Figure 7e, the applied frequencies were 0.2, 0.5, 1, 1.5, and 2 Hz for 30 s each. Cells showed a good response at lower frequencies, while at 2 Hz, their response was not as evident. This may be because the membrane depolarization may be slower than the changing rate of the applied stimuli, and the calcium ions do not enter the cells. However, after another stimulation of 1 Hz and with high potassium solution, cell functionality is again observed.

Discussion

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Nanofiber scaffolds have been extensively studied in TE. These scaffolds could recreate tissue architecture and ECM and further serve as regulators of cellular responses. It is well-known that synthetic materials are biocompatible, but upon degradation, the products generated induce an inflammatory response due to the pH change, whereas natural materials have superior biocompatible properties but weaker mechanical properties. Therefore, hybrid scaffolds are often developed by combining both. (35) PCL has generally been employed in combination with other materials. These scaffolds promoted cell growth and enhanced differentiation, forming aligned myotubes and allowing the exchange of nutrients and mechanical properties. (14,36,37) For instance, Perez-Puyana et al. focused on the use of PCL in combination with elastin, collagen, and gelatin, (24,25) while Kim et al. (38) reported that scaffolds with nanofibers of PCL and gelatin can modulate myoblast differentiation better than scaffolds with only PCL nanofibers. Scaffolds with the combination of PCL with gelatin increased the myogenin expression, contributing to myoblast maturation and myotube formation. (25,39)
This research has focused on the use of PCL and gelatin scaffolds that were generated in the work of Perez-Puyana et al. (25) The degree of alignment in the scaffolds was not an influential factor in cell viability (P = 0.267) and myoblast fusion (P = 0.116). Cell morphology revealed that aligned scaffolds produced significantly narrower myotubes than random scaffolds. This variable may also be influenced by the thickness of the scaffold nanofibers, with the size of the myotubes increasing as the size of the scaffold nanofibers increased, and the scaffolds with the greatest thickness being random scaffolds. (25) Different studies (29,40) have attempted to relate the size of electrospun scaffold fibers without finding definitive results. On the contrary, our small study could pave the way for the theory that fiber size might be related to the size of the formed myotubes. Wang et al. (41) made scaffolds with nanofiber yarn. This work suggested that the diameter of the aligned yarn could enhance cell elongation. In this work, we could see something similar to these results, due to the higher nucleus aspect ratio in scaffolds with aligned orientation, whose diameter of fibers was thinner than random fiber scaffolds.
By studying myotube alignment, aligned scaffolds exhibited significantly greater fiber alignment (P < 0.001). Our research supports the theory described by previous work on the ordering of myotubes in the reorganization of nanofibers of the scaffolds. (13−16,29) This is also supported by authors like Liao et al., (29) who demonstrated that aligned fibers can play a role in the C2C12 orientation. They proved that random fibers promoted nucleus elongation, while aligned fibers showed aligned actin filaments with an elongated cytoplasm. Additionally, Wang et al. (41) suggested that aligned nanofibers could guide the cellular alignment and elongated myotube formation.
Regarding the functionality, we found that random scaffolds had a contraction to the stimulus that may suggest that these may be the best option for clinical applications, such as musculoskeletal regeneration. This may be related to what was visualized in the morphological study, where we could see that the random scaffolds had a maturation greater than that of the aligned scaffolds. However, other factors such as fiber alignment, which are not sufficiently high in this type of scaffold, should be taken into account.
In addition to this, we measured the luminescence increase at the first and second peaks to know the cell fatigue suffered and the increase of luminescence after the stimuli. It has also been seen that despite the contraction that all scaffolds can undergo, there is certainly greater fatigue in random scaffolds after the first stimulus. This fatigue may be greater due to the greater contraction in the first stimulus.
The differentiation of skeletal muscle cells is controlled by the myogenic regulatory factors, which are myogenic factor 5, myogenic differentiation antigen (MyoD), myogenin (MYOG), and myogenic factor 4 (MRF4). However, there are different mechanisms involved in the proliferation and differentiation of these cells, such as mTOR, Notch, and transforming growth factor (TGF-β). (42) Mechanical stimulation has been demonstrated as another factor of activation of different processes involved in the differentiation of skeletal muscle cells. Nagai et al. (43) demonstrated the phosphorylation of extracellular regulated kinase, which is a mitogen-activated proteinkinase, (44) induced by mechanical stimulation. Aguilar-Agon et al. (45) studied the mechano-regulation of different gene transcriptions and observed an increase in some of them, such as IGF-1 mRNA, phosphorylation of Akt, p70S6K, and 4EBP-1. Stretch patterns that resemble developmental stages in vivo have been shown to increase myogenic gene expression, fiber size, and multinucleation, enhancing myotube organization within scaffolds in the direction of stimulation and increasing contractile function. (3,46,47)
We did not demonstrate that mechanical stimulation had an effect on the viability of random (P = 0.398) and aligned scaffolds (P = 0.273). The current literature does not conclude what effect mechanical stimulation may have on this variable. (31) Mechanical stimulation significantly increased the fiber diameter of both random scaffolds (P < 0.001) and aligned scaffolds (P < 0.001). This is because the stimulation signals by recreating the cellular environment of the tissue promote fiber maturation. This result supports Powell et al’s work. (32) Furthermore, alignment was slightly increased in aligned scaffolds (P = 0.023), as detailed by Ahmed et al. (48) and Okano et al. (49) However, we were unable to demonstrate that mechanical stimulation rearranged myotubes in random scaffolds (P = 0.700).
Additionally, previous works have studied cell circularity and its relationship with cell substrate rigidity. (50,51) In our case, we chose to focus on the effect of mechanical stimulation on cell circularity. To a lesser extent, mechanical stimulation also caused the circularity of nucleus in aligned scaffolds to be reduced (P < 0.001), whereas in random scaffolds, it increased (P < 0.001). On the contrary, the aspect ratio was reduced in the aligned scaffolds (P < 0.001), whereas it increased in the random scaffolds (P < 0.001). These results in aligned scaffolds can support the results presented by Ahmed et al. (52) where they found that the nucleus of the cells was elongated in the same orientation of the mechanical stimulation. Despite this, mechanical stimulation significantly increased the nuclear density within the myotubes of both groups (P = 0.004 in random scaffolds; P = 0.004 in aligned scaffolds), i.e., the myotubes of these stimulated scaffolds presented a higher amount of cells that could increase the functionality of the created tissue. This is consistent with what was found in the literature, where some authors support the idea that static culture systems are not able to deliver nutrients to the cells. Therefore, external stimulation, such as mechanical or magnetic stimulation, can significantly increase cell proliferation and differentiation. (53) All this evidence can highlight the positive effect that the use of mechanically stimulated PCL and gelatin scaffolds can have by increasing viability, thickness, nuclear fusion, and targeting.
Finally, the stimulated scaffolds were subjected to a functional test. In random scaffolds, we could see some contractions; however, these responses were not synchronized with the stimulus. In aligned scaffolds, after the first stimulus, the mechanically stimulated scaffolds show a high peak of luminescence. After the second stimulus, the luminescence is practically nonexistent compared to that of the control group. Thus, we found that the scaffolds with mechanically stimulated alignment had higher fatigue at the second stimulus than those without stimulated scaffolds. We consider that the higher fatigue presented by the mechanically stimulated scaffolds may be related to the recovery time of the cells from the previous stimulus, a third stimulus was given after 3 and a half min of rest, and the luminescence increased considerably. Visualizing the luminescence graph, the mechanically stimulated scaffolds have a higher and better-synchronized increase and are even higher than those of the control aligned scaffolds and mechanical random scaffolds. This indicates that the contraction was more pronounced in the mechanically stimulated scaffolds, which underwent a greater contraction in response to the stimuli. This is in line with what was found in the literature and what was demonstrated in our work, regarding how mechanical stimulation leads to a higher cell differentiation of myoblast, as well as to an upregulation of contractile proteins. (29) Aligned mechanically stimulated scaffolds were electrostimulated to know their response to this new stimulus. We could see the good response of the scaffolds to the stimuli at low frequencies. However, at a frequency of 2 Hz, the response was not evident. This may be due to the depolarization time of the cell membranes, which may be slower than the rate at which the stimuli change and does not allow calcium to enter the cells. Previous works showed the contraction behavior of C2C12 with a biphasic pulse at 1 Hz, increasing the fluorescence intensity due to the transient motion of calcium. (54) The cultures were found to remain functional after this, as they showed a response to 1 Hz and high K+ solutions. All of these findings on the functionality of mechanically stimulated aligned scaffolds could be related to increased viability, thickness, nuclear fusion, targeting, and actin expression.
Given the above considerations, our results support the hypothesis put forward by Liao et al. (29) and Candiani et al. (30) following their results on the accumulation of proteins typical of myotubes. Liao et al. (29) demonstrated that stimulation could increase the upregulation of contractile proteins. Candiani et al. (30) determined that behind this accumulation could be cell hyperplasia due to increased cell proliferation prior to differentiation processes and cell hypertrophy with increased incorporation of nucleus into myotubes or stretch-mediated gene regulation leading to increased cytoskeleton protein synthesis. Despite this, cell proliferation may be increased in the mechanically stimulated samples. Other possible mechanisms that could account for the accumulation of cytoskeletal proteins in mechanically stimulated scaffolds are the sustained release of mechanically induced growth factors, which positively influence protein synthesis and prevent myotube atrophy, and the enhanced diffusion between scaffold fibers associated with the stimulation, which allows catabolite/anabolite exchange. In particular, nutrients that have penetrated the scaffold can be pushed toward its center with mechanical perturbation, thus contributing to an overall improvement of cellular metabolic capacities.
Some of the limitations of this work include more assays in the protein expression of skeletal muscle such as myosin heavy chain, MyoD, or myogenin. In this work, we used C2C12 since this cell line is easy to work with. C2C12 are seeded as proliferative myoblast; when reaching confluence, myoblasts begin to differentiate, fusing into elongated, multinucleated ones, (55) but occasionally, the use of C2C12 myoblasts might be limited by their low differentiation potential. (56) Therefore, the study results could seem more robust if a different cell type, such as human mesenchymal cells, were used to pave the way for future steps, including clinical translation. The aligned scaffolds had a thinner nanofiber thickness compared to that of the other scaffolds, which might have led to thinner myotubes and could be seen as a limiting factor. Despite the alignment, perhaps a higher concentration of biomaterials could lead to an increase in nanofiber thickness and, consequently, a greater thickness of the myotubes, affecting their nuclear density and functionality. We could not determine what happened to the gelatin. It is well-known that gelatin loses mechanical properties at physiological temperatures due to solubility. (57) Different works (58) crosslink the gelatin scaffolds, but also, others do not crosslink them. (59,60) However, Jang et al. (61) suggested that the loss of the mechanical properties could happen even in the crosslinked gelatin scaffolds. This approach will be studied in future works. Another limitation is related to the contamination of cell cultures, which increased the difficulty of working with the bioreactor, requiring assembly to be carried out under a laminar flow hood.
In the future, combined stimulation should be studied to evaluate whether it would benefit skeletal muscle development, as previous studies have reported the possible influence of electromechanical stimulation on differentiation in 3D cultures. (29,30) Since this is a tissue created ex vivo, in the future, in vivo behavior could be studied through a preclinical assay. In this way, it would be known whether the functional tissue created can repair the tissue to be repaired or, on the contrary, cell migration would be observed, as in previous work by the group. (24) This would help us to determine whether the tissue created ex vivo would be useful or if the incorporation of a scaffold would be sufficient. It would also be a subject of study if the created tissue should be stimulated in some way after implantation in the model as previous studies described. (62) Finally, concerning the culture time, it would be interesting to study the effect in shorter periods at 2 weeks of stimulation as Candiani et al. did. (30)

Conclusions

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Despite not being able to demonstrate the protein expression of skeletal muscle, we could use electrospun scaffolds stimulated with a bioreactor with mechanical stimulation to produce functional skeletal muscle tissue with the ability of contraction. The PCL scaffold together with gelatin fabricated by electrospinning was ideal, as well as their mechanical stimulation versus other stimuli. We found that these scaffolds meet ideal regeneration conditions, such as increased fiber thickness, alignment, nuclear fusion, nuclear differentiation, and functionality.

Supporting Information

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The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsabm.4c00559.

  • Response against electrostimulation of a mechanically stimulated scaffold (MP4)

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Author Information

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  • Corresponding Authors
    • Francisco José Calero-Castro - Department of General and Digestive Surgery, “Virgen del Rocío” University Hospital/IBiS/CSIC/University of Seville, 41013 Seville, Spain;  Oncology Surgery, Cell Therapy, and Organ Transplantation Group. Institute of Biomedicine of Seville (IBiS), “Virgen del Rocío” University Hospital, IBiS, CSIC/University of Seville, 41013 Sevilla, Spain;  Orcidhttps://orcid.org/0000-0002-6039-3091;  Email: [email protected] [email protected]
    • Alberto Romero - Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, 41012 Sevilla, Spain;  Email: [email protected]
  • Authors
    • Víctor Manuel Perez-Puyana - Departamento de Ingeniería Química, Facultad de Química, Universidad de Sevilla, 41012 Sevilla, Spain;  Orcidhttps://orcid.org/0000-0001-5309-9647
    • Imán Laga - Department of General and Digestive Surgery, “Virgen del Rocío” University Hospital/IBiS/CSIC/University of Seville, 41013 Seville, Spain;  Oncology Surgery, Cell Therapy, and Organ Transplantation Group. Institute of Biomedicine of Seville (IBiS), “Virgen del Rocío” University Hospital, IBiS, CSIC/University of Seville, 41013 Sevilla, Spain
    • Javier Padillo Ruiz - Department of General and Digestive Surgery, “Virgen del Rocío” University Hospital/IBiS/CSIC/University of Seville, 41013 Seville, Spain;  Oncology Surgery, Cell Therapy, and Organ Transplantation Group. Institute of Biomedicine of Seville (IBiS), “Virgen del Rocío” University Hospital, IBiS, CSIC/University of Seville, 41013 Sevilla, Spain
    • Fernando de la Portilla de Juan - Department of General and Digestive Surgery, “Virgen del Rocío” University Hospital/IBiS/CSIC/University of Seville, 41013 Seville, Spain;  Oncology Surgery, Cell Therapy, and Organ Transplantation Group. Institute of Biomedicine of Seville (IBiS), “Virgen del Rocío” University Hospital, IBiS, CSIC/University of Seville, 41013 Sevilla, Spain
  • Author Contributions

    Conceptualization: AR and FPJ; data curation: FJCC, VMPP, and IL; formal analysis: FJCC; funding acquisition: JPR, AR, and FPJ; investigation: FJCC, VMPP, and IL; methodology: FJCC, VMPP, and IL; project administration: AR; resources: JPR, AR, and FPJ; supervision: FPJ; validation: FPJ; visualization and roles/writing─original draft: FJCC; writing─review and editing: VMPP and IL.

  • Notes
    The authors declare no competing financial interest.

Acknowledgments

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This work is part of a research project sponsored by Ministerio de Ciencia e Innovación-Agencia Estatal de Investigación (MCI/AEI/FEDER, EU) from the Spanish Government (ref PID2021-124294OB-C21). The authors gratefully acknowledge their financial support. The authors also acknowledge Junta de Andalucía and European Social Fund for the postdoctoral contract of Víctor Manuel Pérez Puyana (ref PAIDI DOCTOR─Convocatoria 2019/2020, DOC_00586). The contract of F.J.́C.C. was funded by Carlos III Health Institute (Health Research Fund) grant number PI19/01821.

References

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This article references 62 other publications.

  1. 1
    Frontera, W. R.; Ochala, J. Skeletal Muscle: A Brief Review of Structure and Function. Calcif. Tissue Int. 2015, 96, 183– 195,  DOI: 10.1007/s00223-014-9915-y
    Google Scholar
    1
    Skeletal Muscle: A Brief Review of Structure and Function
    Frontera, Walter R.; Ochala, Julien
    Calcified Tissue International (2015), 96 (3), 183-195CODEN: CTINDZ; ISSN:0171-967X. (Springer)
    Skeletal muscle is one of the most dynamic and plastic tissues of the human body. In humans, skeletal muscle comprises approx. 40 % of total body wt. and contains 50-75 % of all body proteins. In general, muscle mass depends on the balance between protein synthesis and degrdn. and both processes are sensitive to factors such as nutritional status, hormonal balance, phys. activity/exercise, and injury or disease, among others. In this review, we discuss the various domains of muscle structure and function including its cytoskeletal architecture, excitation-contraction coupling, energy metab., and force and power generation. We will limit the discussion to human skeletal muscle and emphasize recent scientific literature on single muscle fibers.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhslahtbvK&md5=f06712f45f49f6e4f0c83347fbccb937
  2. 2
    Sabetkish, S.; Currie, P.; Meagher, L. Recent trends in 3D bioprinting technology for skeletal muscle regeneration. Acta Biomater. 2024, 181, 46– 66,  DOI: 10.1016/j.actbio.2024.04.038
    Google Scholar
    There is no corresponding record for this reference.
  3. 3
    Nakayama, K. H.; Shayan, M.; Huang, N. F. Engineering Biomimetic Materials for Skeletal Muscle Repair and Regeneration. Adv. Healthcare Mater. 2019, 8, 1801168,  DOI: 10.1002/adhm.201801168
    Google Scholar
    There is no corresponding record for this reference.
  4. 4
    Mihaly, E.; Altamirano, D. E.; Tuffaha, S.; Grayson, W. Engineering skeletal muscle: Building complexity to achieve functionality. Semin. Cell Dev. Biol. 2021, 119, 61– 69,  DOI: 10.1016/j.semcdb.2021.04.016
    Google Scholar
    There is no corresponding record for this reference.
  5. 5
    Luo, W.; Zhang, H.; Wan, R.; Cai, Y.; Liu, Y.; Wu, Y.; Yang, Y.; Chen, J.; Zhang, D.; Luo, Z. Biomaterials-Based Technologies in Skeletal Muscle Tissue Engineering. Adv. Healthcare Mater. 2024, 13, e2304196  DOI: 10.1002/adhm.202304196
    Google Scholar
    There is no corresponding record for this reference.
  6. 6
    Martins, A. L. L.; Giorno, L. P.; Santos, A. R. Tissue Engineering Applied to Skeletal Muscle: Strategies and Perspectives. Bioengineering 2022, 9, 744,  DOI: 10.3390/bioengineering9120744
    Google Scholar
    There is no corresponding record for this reference.
  7. 7
    Mondal, D.; Tiwari, A. Electrospun Nanomatrix for Tissue Regeneration. In Biomedical materials and diagonostic devices; John Wiley & Sons, 2012; pp 561– 580.
    Google Scholar
    There is no corresponding record for this reference.
  8. 8
    Gouveia, P. J.; Hodgkinson, T.; Amado, I.; Sadowska, J. M.; Ryan, A. J.; Romanazzo, S.; Carroll, S.; Cryan, S. A.; Kelly, D. J.; O’Brien, F. J. Development of collagen-poly(caprolactone)-based core-shell scaffolds supplemented with proteoglycans and glycosaminoglycans for ligament repair. Mater. Sci. Eng., C 2021, 120, 111657,  DOI: 10.1016/j.msec.2020.111657
    Google Scholar
    There is no corresponding record for this reference.
  9. 9
    Malinauskas, M.; Jankauskaite, L.; Aukstikalne, L.; Dabasinskaite, L.; Rimkunas, A.; Mickevicius, T.; Pockevicius, A.; Krugly, E.; Martuzevicius, D.; Ciuzas, D. Cartilage regeneration using improved surface electrospun bilayer polycaprolactone scaffolds loaded with transforming growth factor-beta 3 and rabbit muscle-derived stem cells. Front. Bioeng. Biotechnol. 2022, 10, 971294,  DOI: 10.3389/fbioe.2022.971294
    Google Scholar
    There is no corresponding record for this reference.
  10. 10
    Rahmati, M.; Mills, D. K.; Urbanska, A. M.; Saeb, M. R.; Venugopal, J. R.; Ramakrishna, S.; Mozafari, M. Electrospinning for tissue engineering applications. Prog. Mater. Sci. 2021, 117, 100721,  DOI: 10.1016/j.pmatsci.2020.100721
    Google Scholar
    10
    Electrospinning for tissue engineering applications
    Rahmati, Maryam; Mills, David K.; Urbanska, Aleksandra M.; Saeb, Mohammad Reza; Venugopal, Jayarama Reddy; Ramakrishna, Seeram; Mozafari, Masoud
    Progress in Materials Science (2021), 117 (), 100721CODEN: PRMSAQ; ISSN:0079-6425. (Elsevier Ltd.)
    A review. Tissue engineering makes use of the principles of medicine, biol. and engineering and integrates them into the design of biol. substitutes to restore, maintain and improve the functions of tissue. To fabricate a functional tissue, the engineered structures have to be able to mimic the extracellular matrix (ECM), provide the tissue with oxygen and nutrient circulation as well as remove metabolic wastes in the period of tissue regeneration. Continued efforts have been made in order to fabricate advanced functional three-dimensional scaffolds for tissue engineering. Electrospinning has been recognized and served as one of the most useful techniques based on the resemblance between electrospun fibers and the native tissues. Over the past few decades, a bewildering variety of nanofibrous scaffolds have been developed for various biomedical applications, such as tissue regeneration and therapeutic agent delivery. The present review aims to provide with researchers an in-depth understanding of the promising role and the practical region of applicability of electrospinning in tissue engineering and regenerative medicine by highlighting the outcomes of the most recent studies performed in this field. We address the current strategies used for improving the physicochem. interactions between the cells and the nanofibrous surface. We also discuss the progress and challenges assocd. with the use of electrospinning for tissue engineering and regenerative medicine applications.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXit1Wms7bO&md5=b6c33bd8dd7aa8f3b469d1e99bbbf654
  11. 11
    Jin, G.; He, R.; Sha, B.; Li, W.; Qing, H.; Teng, R.; Xu, F. Electrospun three-dimensional aligned nanofibrous scaffolds for tissue engineering. Mater. Sci. Eng., C 2018, 92, 995– 1005,  DOI: 10.1016/j.msec.2018.06.065
    Google Scholar
    11
    Electrospun three-dimensional aligned nanofibrous scaffolds for tissue engineering
    Jin, Guorui; He, Rongyan; Sha, Baoyong; Li, Wenfang; Qing, Huaibin; Teng, Rui; Xu, Feng
    Materials Science & Engineering, C: Materials for Biological Applications (2018), 92 (), 995-1005CODEN: MSCEEE; ISSN:0928-4931. (Elsevier B.V.)
    A review. Engineered tissue constructs rely on biomaterials as support structures for tissue repair and regeneration. Among these biomaterials, polyester biomaterials have been widely used for scaffold construction because of their merits such as ease in synthesis, degradable properties, and elastomeric characteristics. To mimic the aligned structures of native extracellular matrix (ECM) in tissues such as nerve, heart and tendon, various polyester materials have been fabricated into aligned fibrous scaffolds with fibers ranging from several nanometers to several micrometers in diam. by electrospinning in a simple and reproducible manner. These aligned fibrous scaffolds, esp. the three-dimensional (3D) aligned nanofibrous scaffolds have emerged as a promising soln. for tissue regeneration. Compared with two-dimensional (2D) scaffolds, the 3D aligned nanofibrous scaffolds provide another dimension for cell behaviors such as morphogenesis, migration and cell-cell interactions, which is important in regulating the stem cell fate and tissue regeneration. In this review, we provide an extensive overview on recent efforts for constructing 3D aligned polyester nanofibrous scaffolds by electrospinning, then the results of cell-specific functions dependent on such phys. and chem. cues, and discuss their potentials in improving or restoring damaged tissues.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhtlajt7jK&md5=a7d20e1c93dbb3b33fb814728de41a90
  12. 12
    Xue, J.; Wu, T.; Dai, Y.; Xia, Y. Electrospinning and Electrospun Nanofibers: Methods, Materials, and Applications. Chem. Rev. 2019, 119, 5298– 5415,  DOI: 10.1021/acs.chemrev.8b00593
    Google Scholar
    12
    Electrospinning and Electrospun Nanofibers: Methods, Materials, and Applications
    Xue, Jiajia; Wu, Tong; Dai, Yunqian; Xia, Younan
    Chemical Reviews (Washington, DC, United States) (2019), 119 (8), 5298-5415CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)
    A review. Electrospinning is a versatile and viable technique for generating ultrathin fibers. Remarkable progress has been made with regard to the development of electrospinning methods and engineering of electrospun nanofibers to suit or enable various applications. We aim to provide a comprehensive overview of electrospinning, including the principle, methods, materials, and applications. We begin with a brief introduction to the early history of electrospinning, followed by discussion of its principle and typical app. We then discuss its renaissance over the past two decades as a powerful technol. for the prodn. of nanofibers with diversified compns., structures, and properties. Afterward, we discuss the applications of electrospun nanofibers, including their use as "smart" mats, filtration membranes, catalytic supports, energy harvesting/conversion/storage components, and photonic and electronic devices, as well as biomedical scaffolds. We highlight the most relevant and recent advances related to the applications of electrospun nanofibers by focusing on the most representative examples. We also offer perspectives on the challenges, opportunities, and new directions for future development. At the end, we discuss approaches to the scale-up prodn. of electrospun nanofibers and briefly discuss various types of com. products based on electrospun nanofibers that have found widespread use in our everyday life.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXlvVGmt78%253D&md5=9c35e358c32fdb594d8fa0deada780f2
  13. 13
    Choi, J. S.; Lee, S. J.; Christ, G. J.; Atala, A.; Yoo, J. J. The influence of electrospun aligned poly(ε-caprolactone)/collagen nanofiber meshes on the formation of self-aligned skeletal muscle myotubes. Biomaterials 2008, 29, 2899– 2906,  DOI: 10.1016/j.biomaterials.2008.03.031
    Google Scholar
    13
    The influence of electrospun aligned poly(.vepsiln.-caprolactone)/collagen nanofiber meshes on the formation of self-aligned skeletal muscle myotubes
    Choi, Jin San; Lee, Sang Jin; Christ, George J.; Atala, Anthony; Yoo, James J.
    Biomaterials (2008), 29 (19), 2899-2906CODEN: BIMADU; ISSN:0142-9612. (Elsevier Ltd.)
    Current treatment options for restoring large skeletal muscle tissue defects due to trauma or tumor ablation are limited by the host muscle tissue availability and donor site morbidity of muscle flap implantation. Creation of implantable functional muscle tissue that could restore muscle defects may be a possible soln. To engineer functional muscle tissue for reconstruction, scaffolds that mimic native fibers need to be developed. In this study the authors examd. the feasibility of using poly(ε-caprolactone) (PCL)/collagen based nanofibers using electrospinning as a scaffold system for implantable engineered muscle. The authors investigated whether electrospun nanofibers could guide morphogenesis of skeletal muscle cells and enhance cellular organization. Nanofibers with different fiber orientations were fabricated by electrospinning with a blend of PCL and collagen. Human skeletal muscle cells (hSkMCs) were seeded onto the electrospun PCL/collagen nanofiber meshes and analyzed for cell adhesion, proliferation and organization. The results show that unidirectionally oriented nanofibers significantly induced muscle cell alignment and myotube formation as compared to randomly oriented nanofibers. The aligned composite nanofiber scaffolds seeded with skeletal muscle cells may provide implantable functional muscle tissues for patients with large muscle defects.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXlsV2mtbg%253D&md5=caa6a4203c55edc229099ab246af08b8
  14. 14
    Abarzúa-Illanes, P. N.; Padilla, C.; Ramos, A.; Isaacs, M.; Ramos-Grez, J.; Olguín, H. C.; Valenzuela, L. M. Improving myoblast differentiation on electrospun poly(ε-caprolactone) scaffolds. J. Biomed. Mater. Res., Part A 2017, 105, 2241– 2251,  DOI: 10.1002/jbm.a.36091
    Google Scholar
    14
    Improving myoblast differentiation on electrospun poly(ε-caprolactone) scaffolds
    Abarzua-Illanes, Phammela N.; Padilla, Cristina; Ramos, Andrea; Isaacs, Mauricio; Ramos-Grez, Jorge; Olguin, Hugo C.; Valenzuela, Loreto M.
    Journal of Biomedical Materials Research, Part A (2017), 105 (8), 2241-2251CODEN: JBMRCH; ISSN:1549-3296. (John Wiley & Sons, Inc.)
    Polymer scaffolds are used as an alternative to support tissue regeneration when it does not occur on its own. Cell response on polymer scaffolds is detd. by factors such as polymer compn., topol., and the presence of other mols. We evaluated the cellular response of murine skeletal muscle myoblasts on aligned or unaligned fibers obtained by electrospinning poly(ε-caprolactone) (PCL), and blends with poly(lactic-co-glycolic acid) (PLGA) or decorin, a proteoglycan known to regulate myogenesis. The results showed that aligned PCL fibers with higher content of PLGA promote cell growth and improve the quality of differentiation with PLGA scaffolds having the highest confluence at over 68% of coverage per field of view for myoblasts and more than 7% of coverage for myotubes. At the same time, the addn. of decorin greatly improves the quantity and quality of differentiated cells in terms of cell fusion, myotube length and thickness, being 71, 10, and 51% greater than without the protein, resp. Interestingly, our results suggest that at certain concns., the effect of decorin on myoblast differentiation exceeds the topol. effect of fiber alignment. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2017.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXnslOns74%253D&md5=181c7e8dfe5f737d0eb2759133ba28a3
  15. 15
    Martins, P. M.; Ribeiro, S.; Rebeiro, C.; Sencadas, V.; Gomes, A. C.; Gama, F. M.; Lanceros-Mendez, S. Effect of poling state and morphology of piezoelectric poly(vinylidene fluoride) membranes for skeletal muscle tissue engineering. RSC Adv. 2013, 3, 17938,  DOI: 10.1039/C3RA43499K
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    There is no corresponding record for this reference.
  16. 16
    Aviss, K. J.; Gough, J. E.; Downes, S. Aligned electrospun polymer fibres for skeletal muscle regeneration. Eur. Cells Mater. 2010, 19, 193– 204,  DOI: 10.22203/eCM.v019a19
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    16
    Aligned electrospun polymer fibers for skeletal muscle regeneration
    Aviss, K. J.; Gough, J. E.; Downes, S.
    European Cells and Materials (2010), 19 (), 193-204CODEN: ECMUBB; ISSN:1473-2262. (AO Research Institute Davos)
    Skeletal muscle repair is often overlooked in surgical procedures and in serious burn victims. Creating a tissue-engineered skeletal muscle would not only provide a grafting material for these clin. situations, but could also be used as a valuable true-to-life research tool into diseases affecting muscle tissue. Electrospinning of the elastomer PLGA produced aligned fibers that had the correct topol. to provide contact guidance for myoblast elongation and alignment. In addn., the electrospun scaffold required no surface modifications or incorporation of biol. material for adhesion, elongation, and differentiation of C2C12 murine myoblasts.
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  17. 17
    Aguirre-Chagala, Y. E.; Altuzar, V.; León-Sarabia, E.; Tinoco-Magaña, J. C.; Yañez-Limón, J. M.; Mendoza-Barrera, C. Physicochemical properties of polycaprolactone/collagen/elastin nanofibers fabricated by electrospinning. Mater. Sci. Eng., C 2017, 76, 897– 907,  DOI: 10.1016/j.msec.2017.03.118
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    17
    Physicochemical properties of polycaprolactone/collagen/elastin nanofibers fabricated by electrospinning
    Aguirre-Chagala, Yanet E.; Altuzar, Victor; Leon-Sarabia, Eleazar; Tinoco-Magana, Julio C.; Yanez-Limon, Jose M.; Mendoza-Barrera, Claudia
    Materials Science & Engineering, C: Materials for Biological Applications (2017), 76 (), 897-907CODEN: MSCEEE; ISSN:0928-4931. (Elsevier B.V.)
    Collagen and elastin are the two most abundant proteins in the human body, and as biomaterials offer fascinating properties to composite materials. More detailed investigations including these biomaterials within reinforced composites are still needed. This report describes physicochem. properties of fibers composed of collagen type I, collagen III, elastin and polycaprolactone (PCL). Prior to the electrospinning process, PCL was functionalized through covalent attachment of -NH2 groups by aminolysis reaction with hexamentilendiamine. The fibers were fabricated by electrospinning technique set up with a non-conventional collector. A morphol. comparative study was developed at different rations of collagen type I, observing in some cases two populations of fibers. The diams. and morphol. were analyzed by SEM, observing a wide array of nanostructures with diams. of ∼ 310 to 693 nm. Chem. characterization was assessed by FT-IR spectroscopy and the functionalized PCL was characterized through ninhydrin assay resulting in 0.36 mM NH2/mg fiber. Swelling tests were performed for 24 h, obtaining 320% for the majority of the fibers indicating morphol. stability and good water uptake. In addn., contact angle anal. demonstrated adequate permeability and differences for each system depending mainly upon the type of biopolymer incorporated and the functionalization of PCL, ranging the values from 108° to 17°. Moreover, differential scanning calorimetry results showed a melting temp. (Tm) of ∼ 60°C. The onset degrdn. temps. (Td,onset) ranged between 115 and 148°C, and were obtained by thermogravimetric anal. The local mech. properties of individual fibers were quantified by at. force acoustic microscopy. These results propose that the physicochem. and mech. properties of these scaffolds offer the possibility for enhanced biol. activity Thus, they have a great potential as candidate scaffolds in tissue engineering applications.
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  18. 18
    Annabi, N.; Fathi, A.; Mithieux, S. M.; Weiss, A. S.; Dehghani, F. Fabrication of porous PCL/elastin composite scaffolds for tissue engineering applications. J. Supercrit. Fluids 2011, 59, 157– 167,  DOI: 10.1016/j.supflu.2011.06.010
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    18
    Fabrication of porous PCL/elastin composite scaffolds for tissue engineering applications
    Annabi, Nasim; Fathi, Ali; Mithieux, Suzanne M.; Weiss, Anthony S.; Dehghani, Fariba
    Journal of Supercritical Fluids (2011), 59 (), 157-167CODEN: JSFLEH; ISSN:0896-8446. (Elsevier B.V.)
    The authors present the development of a technique that enables the fabrication of 3-dimensional (3D) porous poly(.vepsiln.-caprolactone) (PCL)/elastin composites. High pressure CO2 was used as a foaming agent to create large pores in a PCL matrix and impregnate elastin into the 3D structure of the scaffold. The effects of process variables such as temp., pressure, processing time, depressurization rate, and salt concn. on the characteristics of PCL scaffolds were detd. Scaffolds with av. pore sizes of 540 μm and porosity of 91% were produced using CO2 at 65 bar, 70 °C, processing time of 1 h, depressurization rate of 15 bar/min, and addn. of 30 wt% salt particles. The PCL/elastin composites were then prepd. under different conditions: ambient pressure, vacuum, and high pressure CO2. The fabrication of composites under vacuum resulted in the formation of nonhomogenous scaffolds. However, uniform 3D composites were formed when using high pressure CO2 at 37 °C and 60 bar.
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  19. 19
    Sant, S.; Hwang, C. M.; Lee, S.-H.; Khademhosseini, A. Hybrid PGS-PCL microfibrous scaffolds with improved mechanical and biological properties. J. Tissue Eng. Regener. Med. 2011, 5, 283– 291,  DOI: 10.1002/term.313
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    19
    Hybrid PGS-PCL microfibrous scaffolds with improved mechanical and biological properties
    Sant, Shilpa; Hwang, Chang Mo; Lee, Sang-Hoon; Khademhosseini, Ali
    Journal of Tissue Engineering and Regenerative Medicine (2011), 5 (4), 283-291CODEN: JTERAX; ISSN:1932-6254. (Wiley-Blackwell)
    Poly(glycerol sebacate) (PGS) is a biodegradable elastomer that has generated great interest as a scaffold material due to its desirable mech. properties. However, the use of PGS in tissue engineering is limited by difficulties in casting micro- and nanofibrous structures, due to high temps. and vacuum required for its curing and limited soly. of the cured polymer. In this paper, we developed microfibrous scaffolds made from blends of PGS and poly(ε-caprolactone) (PCL) using a std. electrospinning set-up. At a given PGS : PCL ratio, higher voltage resulted in significantly smaller fiber diams. (reduced from ∼4 μm to 2.8 μm; p < 0.05). Further increase in voltage resulted in the fusion of fibers. Similarly, higher PGS concns. in the polymer blend resulted in significantly increased fiber diam. (p < 0.01). We further compared the mech. properties of electrospun PGS : PCL scaffolds with those made from PCL. Scaffolds with higher PGS concns. showed higher elastic modulus (EM), ultimate tensile strength (UTS) and ultimate elongation (UE) (p < 0.01) without the need for thermal curing or photocrosslinking. Biol. evaluation of these scaffolds showed significantly improved HUVEC attachment and proliferation compared to PCL-only scaffolds (p < 0.05). Thus, we have demonstrated that simple blends of PGS prepolymer with PCL can be used to fabricate microfibrous scaffolds with mech. properties in the range of a human aortic valve leaflet.
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  20. 20
    Ren, K.; Wang, Y.; Sun, T.; Yue, W.; Zhang, H. Electrospun PCL/gelatin composite nanofiber structures for effective guided bone regeneration membranes. Mater. Sci. Eng., C 2017, 78, 324– 332,  DOI: 10.1016/j.msec.2017.04.084
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    20
    Electrospun PCL/gelatin composite nanofiber structures for effective guided bone regeneration membranes
    Ren, Ke; Wang, Yi; Sun, Tao; Yue, Wen; Zhang, Hongyu
    Materials Science & Engineering, C: Materials for Biological Applications (2017), 78 (), 324-332CODEN: MSCEEE; ISSN:0928-4931. (Elsevier B.V.)
    Guided bone regeneration (GBR) membranes have been proved of great benefit for bone tissue engineering due to the improvement of cell attachment and proliferation. To develop GBR membranes with better biocompatibility and more proper degrdn. ability, here we fabricated polycaprolactone (PCL, polymer)/gelatin (protein) hybrid nanofibrous GBR membranes via electrospinning, followed by crosslinking with genipin. Acetic acid (HAc) was utilized to resolve the phase sepn. of PCL and gelatin, therefore homogeneous PCL/gelatin hybrid nanofibers with different ratios were successfully prepd. FTIR, XPS, TGA, DSC results proved that the proportion of PCL and gelatin in the as-spun nanofiber membranes could be simply adjusted by changing the wt. ratio of PCL and gelatin in the spinning soln. SEM and AFM images demonstrated that all the nanofibers possessed uniform and smooth structures both in two dimension (2D) and three dimension (3D). The mech. tests showed that these nanofibers exhibited appropriate tensile and strength properties, which were suitable for bone tissue engineering. CCK-8 and SEM images revealed that all the membranes were biocompatible to MC3T3-e1 cells. In addn., the in vitro osteogenesis characterizations, alizarin red in normal medium and osteogenesis medium, indicated that the nanofibers could promote bone formation. Therefore, all these results could suggest that our design of electrospun polymer/protein nanofiber membranes was effective for guided bone regeneration.
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  21. 21
    Wu, X.; Ni, S.; Dai, T.; Li, J.; Shao, F.; Liu, C.; Wang, J.; Fan, S.; Tan, Y.; Zhang, L. Biomineralized tetramethylpyrazine-loaded PCL/gelatin nanofibrous membrane promotes vascularization and bone regeneration of rat cranium defects. J. Nanobiotechnol. 2023, 21, 423,  DOI: 10.1186/s12951-023-02155-z
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  22. 22
    Hsu, R.-S.; Chen, P.; Fang, J.; Chen, Y.; Chang, C.; Lu, Y.; Hu, S. Adaptable Microporous Hydrogels of Propagating NGF-Gradient by Injectable Building Blocks for Accelerated Axonal Outgrowth. Adv. Sci. 2019, 6, 1900520,  DOI: 10.1002/advs.201900520
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    22
    Adaptable Microporous Hydrogels of Propagating NGF-Gradient by Injectable Building Blocks for Accelerated Axonal Outgrowth
    Hsu Ru-Siou; Chen Pei-Yueh; Fang Jen-Hung; Chang Chien-Wen; Hu Shang-Hsiu; Chen You-Yin; Lu Yu-Jen
    Advanced science (Weinheim, Baden-Wurttemberg, Germany) (2019), 6 (16), 1900520 ISSN:2198-3844.
    Injectable hydrogels in regeneration medicine can potentially mimic hierarchical natural living tissue and fill complexly shaped defects with minimally invasive implantation procedures. To achieve this goal, however, the versatile hydrogels that usually possess the nonporous structure and uncontrollable spatial agent release must overcome the difficulties in low cell-penetrative rates of tissue regeneration. In this study, an adaptable microporous hydrogel (AMH) composed of microsized building blocks with opposite charges serves as an injectable matrix with interconnected pores and propagates gradient growth factor for spontaneous assembly into a complex shape in real time. By embedding gradient concentrations of growth factors into the building blocks, the propagated gradient of the nerve growth factor, integrated to the cell-penetrative connected pores constructed by the building blocks in the nerve conduit, effectively promotes cell migration and induces dramatic bridging effects on peripheral nerve defects, achieving axon outgrowth of up to 4.7 mm and twofold axon fiber intensity in 4 days in vivo. Such AMHs with intrinsic properties of tunable mechanical properties, gradient propagation of biocues and effective induction of cell migration are potentially able to overcome the limitations of hydrogel-mediated tissue regeneration in general and can possibly be used in clinical applications.
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  23. 23
    Echave, M. C.; Burgo, L. S.; Pedraz, J. L.; Orive, G. Gelatin as Biomaterial for Tissue Engineering. Curr. Pharm. Des. 2017, 23, 3567– 3584,  DOI: 10.2174/0929867324666170511123101
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    23
    Gelatin as Biomaterial for Tissue Engineering
    Echave, Mari C.; Burgo, Laura S.; Pedraz, Jose L.; Orive, Gorka
    Current Pharmaceutical Design (2017), 23 (24), 3567-3584CODEN: CPDEFP; ISSN:1381-6128. (Bentham Science Publishers Ltd.)
    A review. Tissue engineering is considered one of the most important therapeutic strategies of regenerative medicine. The main objective of these new technologies is the development of substitutes made with biomaterials that are able to heal, repair or regenerate injured or diseased tissues and organs. These constructs seek to unlock the limited ability of human tissues and organs to regenerate. In this review, we highlight the convenient intrinsic properties of gelatin for the design and development of advanced systems for tissue engineering. Gelatin is a natural origin protein derived from collagen hydrolysis. We outline herein a state of the art of gelatin-based composites in order to overcome limitations of this polymeric material and modulate the properties of the formulations. Control release of bioactive mols., formulations with conductive properties or systems with improved mech. properties can be obtained using gelatin composites. Many studies have found that the use of calcium phosphate ceramics and diverse synthetic polymers in combination with gelatin improve the mech. properties of the structures. On the other hand, polyaniline and carbon-based nanosubstrates are interesting mols. to provide gelatin-based systems with conductive properties, esp. for cardiac and nerve tissue engineering. Finally, this review provides an overview of the different types of gelatin-based structures including nanoparticles, microparticles, 3D scaffolds, electrospun nanofibers and in situ gelling formulations. Thanks to the significant progress that has already been made, along with others that will be achieved in a near future, the safe and effective clin. implementation of gelatin-based products is expected to accelerate and expand shortly.
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  24. 24
    Perez-puyana, V.; Villanueva, P.; Jiménez-rosado, M.; de la Portilla, F.; Romero, A. Incorporation of elastin to improve polycaprolactone-based scaffolds for skeletal muscle via electrospinning. Polymers 2021, 13, 1501,  DOI: 10.3390/polym13091501
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    24
    Incorporation of elastin to improve polycaprolactone-based scaffolds for skeletal muscle via electrospinning
    Perez-Puyana, Victor; Villanueva, Paula; Jimenez-Rosado, Mercedes; De La Portilla, Fernando; Romero, Alberto
    Polymers (Basel, Switzerland) (2021), 13 (9), 1501CODEN: POLYCK; ISSN:2073-4360. (MDPI AG)
    Skeletal muscle regeneration is increasingly necessary, which is reflected in the increasing no. of studies that are focused on improving the scaffolds used for such regeneration, as well as the incubation protocol. The main objective of this work was to improve the characteristics of polycaprolactone (PCL) scaffolds by incorporating elastin to achieve better cell proliferation and biocompatibility. In addn., two cell incubation protocols (with and without dynamic mech. stimulation) were evaluated to improve the activity and functionality yields of the regenerated cells. The results indicate that the incorporation of elastin generates aligned and more hydrophilic scaffolds with smaller fiber size. In addn., the mech. properties of the resulting scaffolds make them adequate for use in both bioreactors and patients. All these characteristics increase the biocompatibility of these systems, generating a better interconnection with the tissue. However, due to the low maturation achieved in biol. tests, no differences could be found between the incubation with and without dynamic mech. stimulation.
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  25. 25
    Perez-Puyana, V.; Wieringa, P.; Yuste, Y.; de la Portilla, F.; Guererro, A.; Romero, A.; Moroni, L. Fabrication of hybrid scaffolds obtained from combinations of PCL with gelatin or collagen via electrospinning for skeletal muscle tissue engineering. J. Biomed. Mater. Res., Part A 2021, 109, 1600– 1612,  DOI: 10.1002/jbm.a.37156
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    There is no corresponding record for this reference.
  26. 26
    Thangadurai, M.; Srinivasan, S. S.; Sekar, M. P.; Sethuraman, S.; Sundaramurthi, D. Emerging perspectives on 3D printed bioreactors for clinical translation of engineered and bioprinted tissue constructs. J. Mater. Chem. B 2024, 12, 350– 381,  DOI: 10.1039/D3TB01847D
    Google Scholar
    There is no corresponding record for this reference.
  27. 27
    Ravichandran, A.; Liu, Y.; Teoh, S. H. Review: bioreactor design towards generation of relevant engineered tissues: focus on clinical translation. J. Tissue Eng. Regener. Med. 2018, 12, e7– e22,  DOI: 10.1002/term.2270
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    There is no corresponding record for this reference.
  28. 28
    Pennisi, C. P.; Olesen, C. G.; de Zee, M.; Rasmussen, J.; Zachar, V. Uniaxial Cyclic Strain Drives Assembly and Differentiation of Skeletal Myocytes. Tissue Eng., Part A 2011, 17, 2543– 2550,  DOI: 10.1089/ten.tea.2011.0089
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    28
    Uniaxial cyclic strain drives assembly and differentiation of skeletal myocytes
    Pennisi Cristian Pablo; Olesen Christian Gammelgaard; de Zee Mark; Rasmussen John; Zachar Vladimir
    Tissue engineering. Part A (2011), 17 (19-20), 2543-50 ISSN:.
    Ex vivo engineering of skeletal muscle represents an exciting new area of biotechnology. Although the ability of skeletal muscle cells to sense and respond to mechanical forces is well known, strategies based on the use of mechanical stimuli to optimize myogenesis in vitro remain limited. In this work, we describe a simple but powerful method based on uniaxial cyclic tensile strain (CTS) to induce assembly and differentiation of skeletal myocytes in vitro. Confluent mouse myoblastic precursors cultured on flexible-bottomed culture plates were subjected to either uniaxial or equibiaxial CTS. The uniaxial CTS protocol resulted in a highly aligned array of cross-striated fibers, with the major axis of most cells aligned perpendicularly to the axis of strain. In addition, a short period of myogenin activation and significant increase in the myotube/myoblast ratio and percentage of myosin-positive myotubes was found, indicating an enhanced cell differentiation. In contrast, cells under equibiaxial strain regimen had no clear orientation and displayed signs of membrane damage and impaired differentiation. These results, thus, demonstrate that the selection of a proper paradigm is a key element when discussing the relevance of mechanical stimulation for myogenesis in vitro. This study provides a rational framework to optimize engineering of functional skeletal muscle.
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  29. 29
    Liao, I.-C.; Liu, J. B.; Bursac, N.; Leong, K. W. Effect of Electromechanical Stimulation on the Maturation of Myotubes on Aligned Electrospun Fibers. Cell. Mol. Bioeng. 2008, 1, 133– 145,  DOI: 10.1007/s12195-008-0021-y
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    29
    Effect of electrochemical stimulation on the maturation of myotubes on aligned electrospun fibers
    Liao, I.-Chien; Liu, Jason B.; Bursac, Nenad; Leong, Kam W.
    Cellular and Molecular Bioengineering (2008), 1 (2-3), 133-145CODEN: CMBECP; ISSN:1865-5025. (Springer)
    Tissue engineering may provide an alternative to cell injection as a therapeutic soln. for myocardial infarction. A tissue-engineered muscle patch may offer better host integration and higher functional performance. This study examd. the differentiation of skeletal myoblasts on aligned electrospun polyurethane (PU) fibers and in the presence of electromech. stimulation. Skeletal myoblasts cultured on aligned PU fibers showed more pronounced elongation, better alignment, higher level of transient receptor potential cation channel-1 (TRPC-1) expression, upregulation of contractile proteins and higher percentage of striated myotubes compared to those cultured on random PU fibers and film. The resulting tissue constructs generated tetanus forces of 1.1 mN with a 10-ms time to tetanus. Addnl. mech., elec., or synchronized electromech. stimuli applied to myoblasts cultured on PU fibers increased the percentage of striated myotubes from 70% to 85% under optimal stimulation conditions, which was accompanied by an upregulation of contractile proteins such as α-actinin and myosin heavy chain. In describing how electromech. cues can be combined with topog. cue, this study helped move towards the goal of generating a biomimetic microenvironment for engineering of functional skeletal muscle.
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  30. 30
    Candiani, G.; Riboldi, S. A.; Sadr, N.; Lorenzoni, S.; Neuenschwander, P.; Montevecchi, F. M.; Mantero, S. Cyclic Mechanical Stimulation Favors Myosin Heavy Chain Accumulation in Engineered Skeletal Muscle Constructs. J. Appl. Biomater. Biomech. 2010, 8, 68– 75
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    30
    Cyclic mechanical stimulation favors myosin heavy chain accumulation in engineered skeletal muscle constructs
    Candiani, Gabriele; Riboldi, Stefania A.; Sadr, Nasser; Lorenzoni, Stefano; Neuenschwander, Peter; Montevecchi, Franco M.; Mantero, Sara
    Journal of Applied Biomaterials & Biomechanics (2010), 8 (2), 68-75CODEN: JABBA7; ISSN:1722-6899. (Wichtig Editore)
    Purpose: Since stretching plays a key role in skeletal muscle tissue development in vivo, by making use of an innovative bioreactor and a biodegradable microfibrous scaffold (DegraPol) previously developed by our group, we aimed to investigate the effect of mech. conditioning on the development of skeletal muscle engineered constructs, obtained by seeding and culturing murine skeletal muscle cells on electrospun membranes. Methods: Following 5 days of static culture, skeletal muscle constructs were transferred into the bioreactor and further cultured for 13 days, while experiencing a stretching pattern adapted from the literature to resemble mouse development and growth. Sample withdrawal occurred at the onset of cyclic stretching and after 7 and 10 days. Myosin heavy chain (MHC) accumulation in stretched constructs (D) was evaluated by Western blot anal. and immunofluorescence staining, using statically cultured samples (S) as controls. Results: Western blot anal. of MHC on dynamically (D) and statically (S) cultured constructs at different time points showed that, at day 10, the applied stretching pattern led to an eight-fold increase in myosin accumulation in cyclically stretched constructs (D) with respect to the corresponding static controls (S). These results were confirmed by immunofluorescence staining of total sarcomeric MHC. Conclusions: Since previous attempts to reproduce skeletal myogenesis in vitro mainly suffered from the difficulty of driving myoblast development into an architecturally organized array of myosin expressing myotubes, the chance of inducing MHC accumulation via mech. conditioning represents a significant step towards the generation of a functional muscle construct for skeletal muscle tissue engineering applications.
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  31. 31
    Beldjilali-Labro, M.; Garcia Garcia, A.; Farhat, F.; Bedoui, F.; Grosset, J. F.; Dufresne, M.; Legallais, C. Biomaterials in tendon and skeletal muscle tissue engineering: Current trends and challenges. Materials 2018, 11, 1116,  DOI: 10.3390/ma11071116
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    31
    Biomaterials in tendon and skeletal muscle tissue engineering: current trends and challenges
    Beldjilali-Labro, Megane; Garcia, Alejandro Garcia; Farhat, Firas; Bedoui, Fahmi; Grosset, Jean-Francois; Dufresne, Murielle; Legallais, Cecile
    Materials (2018), 11 (7), 1116/1-1116/49CODEN: MATEG9; ISSN:1996-1944. (MDPI AG)
    Tissue engineering is a promising approach to repair tendon and muscle when natural healing fails. Biohybrid constructs obtained after cells' seeding and culture in dedicated scaffolds have indeed been considered as relevant tools for mimicking native tissue, leading to a better integration in vivo. They can also be employed to perform advanced in vitro studies to model the cell differentiation or regeneration processes. In this review, we report and analyze the different solns. proposed in literature, for the reconstruction of tendon, muscle, and the myotendinous junction. They classically rely on the three pillars of tissue engineering, i.e., cells, biomaterials and environment (both chem. and phys. stimuli). We have chosen to present biomimetic or bioinspired strategies based on understanding of the native tissue structure/functions/properties of the tissue of interest. For each tissue, we sorted the relevant publications according to an increasing degree of complexity in the materials' shape or manuf. We present their biol. and mech. performances, obsd. in vitro and in vivo when available. Although there is no consensus for a gold std. technique to reconstruct these musculo-skeletal tissues, the reader can find different ways to progress in the field and to understand the recent history in the choice of materials, from collagen to polymer-based matrixes.
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  32. 32
    Powell, C. A.; Smiley, B. L.; Mills, J.; Vandenburgh, H. H. Mechanical stimulation improves tissue-engineered human skeletal muscle. Am. J. Physiol. 2002, 283, C1557– C1565,  DOI: 10.1152/ajpcell.00595.2001
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    There is no corresponding record for this reference.
  33. 33
    Player, D. J.; Martin, N. R. W.; Passey, S. L.; Sharples, A. P.; Mudera, V.; Lewis, M. P. Acute mechanical overload increases IGF-I and MMP-9 mRNA in 3D tissue-engineered skeletal muscle. Biotechnol. Lett. 2014, 36, 1113– 1124,  DOI: 10.1007/s10529-014-1464-y
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    Acute mechanical overload increases IGF-I and MMP-9 mRNA in 3D tissue-engineered skeletal muscle
    Player, D. J.; Martin, N. R. W.; Passey, S. L.; Sharples, A. P.; Mudera, V.; Lewis, M. P.
    Biotechnology Letters (2014), 36 (5), 1113-1124CODEN: BILED3; ISSN:0141-5492. (Springer)
    Skeletal muscle (SkM) is a tissue that responds to mech. load following both physiol. (exercise) or pathophysiol. (bed rest) conditions. The heterogeneity of human samples and the exptl. and ethical limitations of animal studies provide a rationale for the study of SkM plasticity in vitro. Many current in vitro approaches of mech. loading of SkM disregard the three-dimensional (3D) structure in vivo. Tissue engineered 3D SkM, that displays highly aligned and differentiated myotubes, was used to investigate mechano-regulated gene transcription of genes implicated in hypertrophy/atrophy. Static loading (STL) and ramp loading (RPL) at 10 % strain for 60 min were used as mechano-stimulation with constructs sampled immediately for RNA extn. STL increased IGF-I mRNA compared to both RPL and CON (control, p = 0.003 and 0.011 resp.) while MMP-9 mRNA increased in STL and RPL compared to CON (both p < 0.05). IGFBP-2 mRNA was differentially regulated in RPL and STL compared to CON (p = 0.057), while a redn. in IGFBP-5 mRNA was found for STL and RPL compared to CON (both p < 0.05). There was no effect in the expression of putative atrophic genes, myostatin, MuRF-1 and MAFBx (all p > 0.05). These data demonstrate a transcriptional signature assocd. with SkM hypertrophy within a tissue-engineered model that more greatly recapitulates the in vivo SkM structure compared previously published studies.
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  34. 34
    Vandenburgh, H. H.; Hatfaludy, S.; Karlisch, P.; Shansky, J. Skeletal muscle growth is stimulated by intermittent stretch-relaxation in tissue culture. Am. J. Physiol. 1989, 256, C674– C682,  DOI: 10.1152/ajpcell.1989.256.3.C674
    Google Scholar
    There is no corresponding record for this reference.
  35. 35
    Chen, S.; Li, R.; Li, X.; Xie, J. Electrospinning: An enabling nanotechnology platform for drug delivery and regenerative medicine. Adv. Drug Delivery Rev. 2018, 132, 188– 213,  DOI: 10.1016/j.addr.2018.05.001
    Google Scholar
    35
    Electrospinning: An enabling nanotechnology platform for drug delivery and regenerative medicine
    Chen, Shixuan; Li, Ruiquan; Li, Xiaoran; Xie, Jingwei
    Advanced Drug Delivery Reviews (2018), 132 (), 188-213CODEN: ADDREP; ISSN:0169-409X. (Elsevier B.V.)
    Electrospinning provides an enabling nanotechnol. platform for generating a rich variety of novel structured materials in many biomedical applications including drug delivery, biosensing, tissue engineering, and regenerative medicine. In this review article, we begin with a thorough discussion on the method of producing 1D, 2D, and 3D electrospun nanofiber materials. In particular, we emphasize on how the 3D printing technol. can contribute to the improvement of traditional electrospinning technol. for the fabrication of 3D electrospun nanofiber materials as drug delivery devices/implants, scaffolds or living tissue constructs. We then highlight several notable examples of electrospun nanofiber materials in specific biomedical applications including cancer therapy, guiding cellular responses, engineering in vitro 3D tissue models, and tissue regeneration. Finally, we finish with conclusions and future perspectives of electrospun nanofiber materials for drug delivery and regenerative medicine.
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  36. 36
    Wang, L.; Wu, Y.; Guo, B.; Ma, P. X. Nanofiber Yarn/Hydrogel Core–Shell Scaffolds Mimicking Native Skeletal Muscle Tissue for Guiding 3D Myoblast Alignment, Elongation, and Differentiation. ACS Nano 2015, 9, 9167– 9179,  DOI: 10.1021/acsnano.5b03644
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    36
    Nanofiber Yarn/Hydrogel Core-Shell Scaffolds Mimicking Native Skeletal Muscle Tissue for Guiding 3D Myoblast Alignment, Elongation, and Differentiation
    Wang, Ling; Wu, Yaobin; Guo, Baolin; Ma, Peter X.
    ACS Nano (2015), 9 (9), 9167-9179CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
    Designing scaffolds that can mimic native skeletal muscle tissue and induce 3D cellular alignment and elongated myotube formation remains an ongoing challenge for skeletal muscle tissue engineering. Herein, we present a simple technique to generate core-shell composite scaffolds for mimicking native skeletal muscle structure, which comprise the aligned nanofiber yarn (NFY) core and the photocurable hydrogel shell. The aligned NFYs are prepd. by the hybrid compn. including poly(caprolactone), silk fibroin, and polyaniline via a developed dry-wet electrospinning method. A series of core-shell column and sheet composite scaffolds are ultimately obtained by encapsulating a piece and layers of aligned NFY cores within the hydrogel shell after photo-crosslinking. C2C12 myoblasts are seeded within the core-shell scaffolds, and the good biocompatibility of these scaffolds and their ability to induce 3D cellular alignment and elongation are successfully demonstrated. Furthermore, the 3D elongated myotube formation within core-shell scaffolds is also performed after long-term cultivation. These data suggest that these core-shell scaffolds combine the aligned NFY core that guides the myoblast alignment and differentiation and the hydrogel shell that provides a suitable 3D environment for nutrition exchange and mech. protection to perform a great practical application for skeletal muscle regeneration.
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  37. 37
    Cha, S. H.; Lee, H. J.; Koh, W. G. Study of myoblast differentiation using multi-dimensional scaffolds consisting of nano and micropatterns. Biomater. Res. 2017, 21, 1,  DOI: 10.1186/s40824-016-0087-x
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    37
    Study of myoblast differentiation using multi-dimensional scaffolds consisting of nano and micropatterns
    Cha, Sung Ho; Lee, Hyun Jong; Koh, Won-Gun
    Biomaterials Research (2017), 21 (), 1/1-1/9CODEN: BRIEFJ; ISSN:2055-7124. (BioMed Central Ltd.)
    Background: The topog. cue is major influence on skeletal muscle cell culture because the structure is highly organized and consists of long parallel bundles of multinucleated myotubes that are formed by differentiation and fusion of myoblast satellite cells. In this tech. report, we fabricated a multiscale scaffold using electrospinning and poly (ethylene glycol) (PEG) hydrogel micropatterns to monitor the cell behaviors on nano- and micro-alignment combined scaffolds with different combinations of angles. Results: We fabricated multiscale scaffolds that provide biocompatible and extracellular matrix (ECM)-mimetic environments via electrospun nanofiber and PEG hydrogel micro patterning. MTT assays demonstrated an almost four-fold increase in the proliferation rate during the 7 days of cell culture for all of the exptl. groups. Cell orientation and elongation were measured to confirm the myogenic potential. On the aligned fibrous scaffolds, more than 90% of the cells were dispersed±20° of the fiber orientation. To det. cell elongation, we monitored nuclei aspect ratios. On a random nanofiber, the cells demonstrated an aspect ratio of 1.33, but on perpendicular and parallel nanofibers, the aspect ratio was greater than 2. Myosin heavy chain (MHC) expression was significantly higher (i) on parallel compared to random fibers, (ii) the 100 μm compared to the 200 μm line pattern. We confirmed the disparate trends of myotube formation that can be provoked through multi-dimensional scaffolds. Conclusion: We studied more favorable environments that induce cell alignment and elongation for myogenesis by combining nano- and micro-scale patterns. The fabricated system can serve as a novel multi-dimensional platform to study in vitro cell behaviors.
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  38. 38
    Kim, M. S.; Jun, I.; Shin, Y. M.; Jang, W.; Kim, S. I.; Shin, H. The development of genipin-crosslinked poly(caprolactone) (PCL)/gelatin nanofibers for tissue engineering applications. Macromol. Biosci. 2010, 10, 91– 100,  DOI: 10.1002/mabi.200900168
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    38
    The Development of Genipin-Crosslinked Poly(caprolactone) (PCL)/Gelatin Nanofibers for Tissue Engineering Applications
    Kim, Min Sup; Jun, Indong; Shin, Young Min; Jang, Wonhee; Kim, Sun I.; Shin, Heungsoo
    Macromolecular Bioscience (2010), 10 (1), 91-100CODEN: MBAIBU; ISSN:1616-5187. (Wiley-VCH Verlag GmbH & Co. KGaA)
    Composite nanofibers of poly(caprolactone) (PCL) and gelatin crosslinked with genipin are prepd. The contact angles and mech. properties of crosslinked PCL-gelatin nanofibers decrease as the gelatin content increases. The proliferation of myoblasts is higher in the crosslinked PCL-gelatin nanofibers than in the PCL nanofibers, and the formation of myotubes is only obsd. on the crosslinked PCL-gelatin nanofibers. The expression level of myogenin, myosin heavy chain, and troponin T genes is increased as the gelatin content is increased. The results suggest that PCL-gelatin nanofibers crosslinked with genipin can be used as a substrate to modulate proliferation and differentiation of myoblasts, presenting potential applications in muscle tissue engineering.
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  39. 39
    Ostrovidov, S.; Shi, X.; Zhang, L.; Liang, X.; Kim, S. B.; Fujie, T.; Ramalingam, M.; Chen, M.; Nakajima, K.; Al-Hazmi, F. Myotube formation on gelatin nanofibers – Multi-walled carbon nanotubes hybrid scaffolds. Biomaterials 2014, 35, 6268– 6277,  DOI: 10.1016/j.biomaterials.2014.04.021
    Google Scholar
    There is no corresponding record for this reference.
  40. 40
    Drexler, J. W.; Powell, H. M. Regulation of electrospun scaffold stiffness via coaxial core diameter. Acta Biomater. 2011, 7, 1133– 1139,  DOI: 10.1016/j.actbio.2010.10.025
    Google Scholar
    40
    Regulation of electrospun scaffold stiffness via coaxial core diameter
    Drexler, J. W.; Powell, H. M.
    Acta Biomaterialia (2011), 7 (3), 1133-1139CODEN: ABCICB; ISSN:1742-7061. (Elsevier Ltd.)
    Scaffold mechanics influence cellular behavior, including migration, phenotype and viability. Scaffold stiffness is commonly modulated through crosslinking, polymer d., or bioactive coatings on stiff substrates. These approaches provide useful information about cellular response to substrate stiffness; however, they are not ideal as the processing can change substrate morphol., d. or chem. Coaxial electrospinning was investigated as a fabrication method to produce scaffolds with tunable stiffness and strength without changing architecture or surface chem. Core soln. concn., solvent and feed rate were utilized to control core diam. with higher soln. concn. and feed rate pos. correlating with increased fiber diam. and stiffness. Coaxial scaffolds electrospun with an 8 wt./vol.% polycaprolactone (PCL)-HFP soln. at 1 mL h-1 formed scaffolds with an av. core diam. of 1.1 ± 0.2 μm and stiffness of 0.027 ± 3.3 × 10-3 N mm-1. In contrast, fibers which were 2.6 ± 0.1 μm in core diam. yielded scaffolds with a stiffness of 0.065 ± 4.7 × 10-3 N mm-1. Strength and stiffness pos. correlated with core diam. with no significant difference in total fiber diam. and interfiber distance obsd. in as-spun scaffolds. These data indicate that coaxial core diam. can be utilized to tailor mech. properties of three-dimensional scaffolds and would provide an ideal scaffold for assessing the effect of scaffold mechanics on cell behavior.
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  41. 41
    Wang, L.; Wu, Y.; Guo, B.; Ma, P. X. Nanofiber Yarn/Hydrogel Core–Shell Scaffolds Mimicking Native Skeletal Muscle Tissue for Guiding 3D Myoblast Alignment, Elongation, and Differentiation. ACS Nano 2015, 9, 9167– 9179,  DOI: 10.1021/acsnano.5b03644
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    41
    Nanofiber Yarn/Hydrogel Core-Shell Scaffolds Mimicking Native Skeletal Muscle Tissue for Guiding 3D Myoblast Alignment, Elongation, and Differentiation
    Wang, Ling; Wu, Yaobin; Guo, Baolin; Ma, Peter X.
    ACS Nano (2015), 9 (9), 9167-9179CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
    Designing scaffolds that can mimic native skeletal muscle tissue and induce 3D cellular alignment and elongated myotube formation remains an ongoing challenge for skeletal muscle tissue engineering. Herein, we present a simple technique to generate core-shell composite scaffolds for mimicking native skeletal muscle structure, which comprise the aligned nanofiber yarn (NFY) core and the photocurable hydrogel shell. The aligned NFYs are prepd. by the hybrid compn. including poly(caprolactone), silk fibroin, and polyaniline via a developed dry-wet electrospinning method. A series of core-shell column and sheet composite scaffolds are ultimately obtained by encapsulating a piece and layers of aligned NFY cores within the hydrogel shell after photo-crosslinking. C2C12 myoblasts are seeded within the core-shell scaffolds, and the good biocompatibility of these scaffolds and their ability to induce 3D cellular alignment and elongation are successfully demonstrated. Furthermore, the 3D elongated myotube formation within core-shell scaffolds is also performed after long-term cultivation. These data suggest that these core-shell scaffolds combine the aligned NFY core that guides the myoblast alignment and differentiation and the hydrogel shell that provides a suitable 3D environment for nutrition exchange and mech. protection to perform a great practical application for skeletal muscle regeneration.
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  42. 42
    Zhang, Y.; Li, S.; Wen, X.; Tong, H.; Li, S.; Yan, Y. MYOC Promotes the Differentiation of C2C12 Cells by Regulation of the TGF-β Signaling Pathways via CAV1. Biology 2021, 10, 686,  DOI: 10.3390/biology10070686
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    42
    MYOC Promotes the Differentiation of C2C12 Cells by Regulation of the TGF-β Signaling Pathways via CAV1
    Zhang, Yuhan; Li, Shuang; Wen, Xin; Tong, Huili; Li, Shufeng; Yan, Yunqin
    Biology (Basel, Switzerland) (2021), 10 (7), 686CODEN: BBSIBX; ISSN:2079-7737. (MDPI AG)
    Simple Summary: MYOC is a secreted glycoprotein and it expresses at high levels in skeletal muscle cells. However, the function of MYOC in muscle is still unclear. Accordingly, in this study, we examd. that MYOC expression increased gradually during C2C12 differentiation and it could promote the differentiation of C2C12. Furthermore, we demonstrated that MYOC could bind to CAV1. We further confirmed that CAV1 could pos. regulate C2C12 differentiation through the TGF-β pathway. At last, we detd. the relationship among MYOC, CAV1 and TGF-β. We found that MYOC promoted the differentiation of C2C12 cells by regulation of the TGF-β signaling pathways via CAV1. The present study is the first to demonstrate the mechanism of action of MYOC in C2C12 cells. It provides a novel method of exploring the mechanism of muscle differentiation and represents a potential novel method for the treatment of muscle diseases. Abstr.: Myocilin (MYOC) is a glycoprotein encoded by a gene assocd. with glaucoma pathol. In addn. to the eyes, it also expresses at high transcription levels in the heart and skeletal muscle. MYOC affects the formation of the murine gastrocnemius muscle and is assocd. with the differentiation of mouse osteoblasts, but its role in the differentiation of C2C12 cells has not yet been reported. Here, MYOC expression was found to increase gradually during the differentiation of C2C12 cells. Overexpression of MYOC resulted in enhanced differentiation of C2C12 cells while its inhibition caused reduced differentiation. Furthermore, immunopptn. indicated that MYOC binds to Caveolin-1 (CAV1), a protein that influences the TGF-β pathway. Laser confocal microscopy also revealed the common sites of action of the two during the differentiation of C2C12 cells. Addnl., CAV1 was upregulated significantly as C2C12 cells differentiated, with CAV1 able to influence the differentiation of the cells. Furthermore, the Western blotting anal. demonstrated that the expression of MYOC affected the TGF-β pathway. Finally, MYOC was overexpressed while CAV1 was inhibited. The results indicate that reduced CAV1 expression blocked the promotion of C2C12 cell differentiation by MYOC. In conclusion, the results demonstrated that MYOC regulates TGF-β by influencing CAV1 to promote the differentiation of C2C12 cells.
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  43. 43
    Nagai, Y.; Yokoi, H.; Kaihara, K.; Naruse, K. The mechanical stimulation of cells in 3D culture within a self-assembling peptide hydrogel. Biomaterials 2012, 33, 1044– 1051,  DOI: 10.1016/j.biomaterials.2011.10.049
    Google Scholar
    43
    The mechanical stimulation of cells in 3D culture within a self-assembling peptide hydrogel
    Nagai, Yusuke; Yokoi, Hidenori; Kaihara, Keiko; Naruse, Keiji
    Biomaterials (2012), 33 (4), 1044-1051CODEN: BIMADU; ISSN:0142-9612. (Elsevier Ltd.)
    The aim of this present study was to provide a scaffold as a tool for the investigation of the effect of mech. stimulation on three-dimensionally cultured cells. For this purpose, we developed an artificial self-assembling peptide (SPG-178) hydrogel scaffold. The structural properties of the SPG-178 peptide were confirmed by attenuated total reflection-Fourier transform IR spectroscopy (ATR-FTIR) and transmission electron microscopy (TEM). The mech. properties of the SPG-178 hydrogel were studied using rheol. measurements. The SPG-178 peptide was able to form a stable, transparent hydrogel in a neutral pH environment. In the SPG-178 hydrogel, mouse skeletal muscle cells proliferated successfully (increased by 12.4 ± 1.5 times during 8 days of incubation; mean ± SEM). When the scaffold was statically stretched, a rapid phosphorylation of ERK was obsd. (increased by 2.8 ± 0.2 times; mean ± SEM). These results demonstrated that the developed self-assembling peptide gel is non-cytotoxic and is a suitable tool for the investigation of the effect of mech. stimulation on three-dimensional cell culture.
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  44. 44
    Rauch, C.; Loughna, P. T. Stretch-induced activation of ERK in myocytes is p38 and calcineurin-dependent. Cell Biochem. Funct. 2008, 26, 866– 869,  DOI: 10.1002/cbf.1518
    Google Scholar
    There is no corresponding record for this reference.
  45. 45
    Aguilar-Agon, K. W.; Capel, A. J.; Martin, N. R. W.; Player, D. J.; Lewis, M. P. Mechanical loading stimulates hypertrophy in tissue-engineered skeletal muscle: Molecular and phenotypic responses. J. Cell. Physiol. 2019, 234, 23547– 23558,  DOI: 10.1002/jcp.28923
    Google Scholar
    There is no corresponding record for this reference.
  46. 46
    Heher, P.; Maleiner, B.; Prüller, J.; Teuschl, A. H.; Kollmitzer, J.; Monforte, X.; Wolbank, S.; Redl, H.; Rünzler, D.; Fuchs, C. A novel bioreactor for the generation of highly aligned 3D skeletal muscle-like constructs through orientation of fibrin via application of static strain. Acta Biomater. 2015, 24, 251– 265,  DOI: 10.1016/j.actbio.2015.06.033
    Google Scholar
    46
    A novel bioreactor for the generation of highly aligned 3D skeletal muscle-like constructs through orientation of fibrin via application of static strain
    Heher, Philipp; Maleiner, Babette; Prueller, Johanna; Teuschl, Andreas Herbert; Kollmitzer, Josef; Monforte, Xavier; Wolbank, Susanne; Redl, Heinz; Ruenzler, Dominik; Fuchs, Christiane
    Acta Biomaterialia (2015), 24 (), 251-265CODEN: ABCICB; ISSN:1742-7061. (Elsevier Ltd.)
    The generation of functional biomimetic skeletal muscle constructs is still one of the fundamental challenges in skeletal muscle tissue engineering. With the notion that structure strongly dictates functional capabilities, a myriad of cell types, scaffold materials and stimulation strategies have been combined. To further optimize muscle engineered constructs, we have developed a novel bioreactor system (MagneTissue) for rapid engineering of skeletal muscle-like constructs with the aim to resemble native muscle in terms of structure, gene expression profile and maturity. Myoblasts embedded in fibrin, a natural hydrogel that serves as extracellular matrix, are subjected to mech. stimulation via magnetic force transmission. We identify static mech. strain as a trigger for cellular alignment concomitant with the orientation of the scaffold into highly organized fibrin fibrils. This ultimately yields myotubes with a more mature phenotype in terms of sarcomeric patterning, diam. and length. On the mol. level, a faster progression of the myogenic gene expression program is evident as myogenic detn. markers MyoD and Myogenin as well as the Ca2+ dependent contractile structural marker TnnT1 are significantly upregulated when strain is applied. The major advantage of the MagneTissue bioreactor system is that the generated tension is not exclusively relying on the strain generated by the cells themselves in response to scaffold anchoring but its ability to subject the constructs to individually adjustable strain protocols. In future work, this will allow applying mech. stimulation with different strain regimes in the maturation process of tissue engineered constructs and elucidating the role of mechanotransduction in myogenesis. Mech. stimulation of tissue engineered skeletal muscle constructs is a promising approach to increase tissue functionality. We have developed a novel bioreactor-based 3D culture system, giving the user the possibility to apply different strain regimes like static, cyclic or ramp strain to myogenic precursor cells embedded in a fibrin scaffold. Application of static mech. strain leads to alignment of fibrin fibrils along the axis of strain and concomitantly to highly aligned myotube formation. Addnl., the pattern of myogenic gene expression follows the temporal progression obsd. in vivo with a more thorough induction of the myogenic program when static strain is applied. Ultimately, the strain protocol used in this study results in a higher degree of muscle maturity demonstrated by enhanced sarcomeric patterning and increased myotube diam. and length. The introduced bioreactor system enables new possibilities in muscle tissue engineering as longer cultivation periods and different strain applications will yield tissue engineered muscle-like constructs with improved characteristics in regard to functionality and biomimicry.
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  47. 47
    Li, Y.; Huang, G.; Gao, B.; Li, M.; Genin, G. M.; Lu, T. J.; Xu, F. Magnetically actuated cell-laden microscale hydrogels for probing strain-induced cell responses in three dimensions. NPG Asia Mater. 2016, 8, e238  DOI: 10.1038/am.2015.148
    Google Scholar
    47
    Magnetically actuated cell-laden microscale hydrogels for probing strain-induced cell responses in three dimensions
    Li, Yuhui; Huang, Guoyou; Gao, Bin; Li, Moxiao; Genin, Guy M.; Lu, Tian Jian; Xu, Feng
    NPG Asia Materials (2016), 8 (1), e238CODEN: NAMPCE; ISSN:1884-4057. (Nature Publishing Group)
    Living cells respond to their mech. microenvironments during development, healing, tissue remodeling and homeostasis attainment. However, this mechanosensitivity has not yet been established definitively for cells in three-dimensional (3D) culture environments, in part because of challenges assocd. with providing uniform and consistent 3D environments that can deliver a large range of physiol. and pathophysiol. strains to cells. Here, we report microscale magnetically actuated, cell-laden hydrogels (μMACs) for investigating the strain-induced cell response in 3D cultures. μMACs provide high-throughput arrays of defined 3D cellular microenvironments that undergo reversible, relatively homogeneous deformation following non-contact actuation under external magnetic fields. We present a technique that not only enables the application of these high strains (60%) to cells but also enables simplified microscopy of these specimens under tension. We apply the technique to reveal cellular strain-threshold and satn. behaviors that are substantially different from their 2D analogs, including spreading, proliferation, and differentiation. μMACs offer insights for mechanotransduction and may also provide a view of how cells respond to the extracellular matrix in a 3D manner.
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  48. 48
    Ahmed, W. W.; Wolfram, T.; Goldyn, A. M.; Bruellhoff, K.; Rioja, B. A.; Möller, M.; Spatz, J. P.; Saif, T. A.; Groll, J.; Kemkemer, R. Myoblast morphology and organization on biochemically micro-patterned hydrogel coatings under cyclic mechanical strain. Biomaterials 2010, 31, 250– 258,  DOI: 10.1016/j.biomaterials.2009.09.047
    Google Scholar
    There is no corresponding record for this reference.
  49. 49
    Okano, T.; Satoh, S.; Oka, T.; Matsuda, T. Tissue engineering of skeletal muscle. Highly dense, highly oriented hybrid muscular tissues biomimicking native tissues. ASAIO J. 1997, 43, M753,  DOI: 10.1097/00002480-199709000-00084
    Google Scholar
    There is no corresponding record for this reference.
  50. 50
    Ahadian, S.; Ramón-Azcón, J.; Chang, H.; Liang, X.; Kaji, H.; Shiku, H.; Nakajima, K.; Ramalingam, M.; Wu, H.; Matsue, T. Electrically regulated differentiation of skeletal muscle cells on ultrathin graphene-based films. RSC Adv. 2014, 4, 9534– 9541,  DOI: 10.1039/c3ra46218h
    Google Scholar
    50
    Electrically regulated differentiation of skeletal muscle cells on ultrathin graphene-based films
    Ahadian, Samad; Ramon-Azcon, Javier; Chang, Haixin; Liang, Xiaobin; Kaji, Hirokazu; Shiku, Hitoshi; Nakajima, Ken; Ramalingam, Murugan; Wu, Hongkai; Matsue, Tomokazu; Khademhosseini, Ali
    RSC Advances (2014), 4 (19), 9534-9541CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)
    The elec. cond. of graphene provides a unique opportunity to modify the behavior of elec. sensitive cells. Here, we demonstrate that C2C12 myoblasts that were cultured on ultrathin thermally reduced graphene (TR-Graphene) films had more favorable cell adhesion and spreading compared to those on graphene oxide (GO) and glass slide substrates, comparable with conventional Petri dish. More importantly, we demonstrate that elec. stimulation significantly enhanced myoblast cell differentiation on a TR-Graphene substrate compared to GO and glass slide surfaces as confirmed by the expression of myogenic genes and proteins. These results highlight the potential applications of graphene-based materials for cell-based studies, bioelectronics, and biorobotics.
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  51. 51
    Gao, J.; Sun, X.; Ma, Y.; Qin, W.; Li, J.; Jin, Z.; Qiu, J.; Zhang, H. Myotube formation on micropatterns guiding by centripetal cellular motility and crowding. Mater. Today Bio 2024, 28, 101195,  DOI: 10.1016/j.mtbio.2024.101195
    Google Scholar
    There is no corresponding record for this reference.
  52. 52
    Siegel, R.; Ma, J.; Zou, Z.; Jemal, A. Cancer statistics. Ca-Cancer J. Clin. 2014, 64, 9– 29,  DOI: 10.3322/caac.21208
    Google Scholar
    52
    Cancer statistics, 2014
    Siegel Rebecca; Ma Jiemin; Zou Zhaohui; Jemal Ahmedin
    CA: a cancer journal for clinicians (2014), 64 (1), 9-29 ISSN:.
    Each year, the American Cancer Society estimates the numbers of new cancer cases and deaths that will occur in the United States in the current year and compiles the most recent data on cancer incidence, mortality, and survival. Incidence data were collected by the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries and mortality data were collected by the National Center for Health Statistics. A total of 1,665,540 new cancer cases and 585,720 cancer deaths are projected to occur in the United States in 2014. During the most recent 5 years for which there are data (2006-2010), delay-adjusted cancer incidence rates declined slightly in men (by 0.6% per year) and were stable in women, while cancer death rates decreased by 1.8% per year in men and by 1.4% per year in women. The combined cancer death rate (deaths per 100,000 population) has been continuously declining for 2 decades, from a peak of 215.1 in 1991 to 171.8 in 2010. This 20% decline translates to the avoidance of approximately 1,340,400 cancer deaths (952,700 among men and 387,700 among women) during this time period. The magnitude of the decline in cancer death rates from 1991 to 2010 varies substantially by age, race, and sex, ranging from no decline among white women aged 80 years and older to a 55% decline among black men aged 40 years to 49 years. Notably, black men experienced the largest drop within every 10-year age group. Further progress can be accelerated by applying existing cancer control knowledge across all segments of the population.
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  53. 53
    Mueller, C.; Trujillo-Miranda, M.; Maier, M.; Heath, D. E.; O’Connor, A. J.; Salehi, S. Effects of External Stimulators on Engineered Skeletal Muscle Tissue Maturation. Adv. Mater. Interfaces 2021, 8, 2001167,  DOI: 10.1002/admi.202001167
    Google Scholar
    There is no corresponding record for this reference.
  54. 54
    Kim, W. J.; Jang, C. H.; Kim, G. H. A Myoblast-Laden Collagen Bioink with Fully Aligned Au Nanowires for Muscle-Tissue Regeneration. Nano Lett. 2019, 19, 8612– 8620,  DOI: 10.1021/acs.nanolett.9b03182
    Google Scholar
    There is no corresponding record for this reference.
  55. 55
    Herbst, A.; Aiken, J. M.; McKenzie, D. Replication of prions in differentiated muscle cells. Prion 2014, 8, 166– 168,  DOI: 10.4161/pri.27890
    Google Scholar
    There is no corresponding record for this reference.
  56. 56
    Smoak, M. M.; Hogan, K. J.; Grande-Allen, K. J.; Mikos, A. G. Bioinspired electrospun dECM scaffolds guide cell growth and control the formation of myotubes. Sci. Adv. 2021, 7, eabg4123  DOI: 10.1126/sciadv.abg4123
    Google Scholar
    There is no corresponding record for this reference.
  57. 57
    Campiglio, C. E.; Contessi Negrini, N.; Farè, S.; Draghi, L. Cross-linking strategies for electrospun gelatin scaffolds. Materials 2019, 12, 2476,  DOI: 10.3390/ma12152476
    Google Scholar
    57
    Cross-linking strategies for electrospun gelatin scaffolds
    Campiglio, Chiara Emma; Negrini, Nicola Contessi; Fare, Silvia; Draghi, Lorenza
    Materials (2019), 12 (15), 2476CODEN: MATEG9; ISSN:1996-1944. (MDPI AG)
    Electrospinning is an exceptional technol. to fabricate sub-micrometric fiber scaffolds for regenerative medicine applications and to mimic the morphol. and the chem. of the natural extracellular matrix (ECM). Although most synthetic and natural polymers can be electrospun, gelatin frequently represents a material of choice due to the presence of cell-interactive motifs, its wide availability, low cost, easy processability, and biodegradability. However, crosslinking is required to stabilize the structure of the electrospun matrixes and avoid gelatin dissoln. at body temp. Different phys. and chem. crosslinking protocols have been described to improve electrospun gelatin stability and to preserve the morphol. fibrous arrangement of the electrospun gelatin scaffolds. Here, we review the main current strategies. For each method, the crosslinking mechanism and its efficiency, the influence of electrospinning parameters, and the resulting fiber morphol. are considered. The main drawbacks as well as the open challenges are also discussed.
    >> More from SciFinder ®
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  58. 58
    Demina, T. S.; Bolbasov, E. N.; Peshkova, M. A.; Efremov, Y. M.; Bikmulina, P. Y.; Birdibekova, A. V.; Popyrina, T. N.; Kosheleva, N. V.; Tverdokhlebov, S. I.; Timashev, P. S. Electrospinning vs. Electro-Assisted Solution Blow Spinning for Fabrication of Fibrous Scaffolds for Tissue Engineering. Polymers 2022, 14, 5254,  DOI: 10.3390/polym14235254
    Google Scholar
    There is no corresponding record for this reference.
  59. 59
    Shao, Y. H.; Huang, S. M.; Liu, S. M.; Chen, J. C.; Chen, W. C. Hybrid-Aligned Fibers of Electrospun Gelatin with Antibiotic and Polycaprolactone Composite Membranes as an In Vitro Drug Delivery System to Assess the Potential Repair Capacity of Damaged Cornea. Polymers 2024, 16, 448,  DOI: 10.3390/polym16040448
    Google Scholar
    There is no corresponding record for this reference.
  60. 60
    Rodríguez-Martín, M.; Aguilar, J. M.; Castro-Criado, D.; Romero, A. Characterization of Gelatin-Polycaprolactone Membranes by Electrospinning. Biomimetics 2024, 9, 70,  DOI: 10.3390/biomimetics9020070
    Google Scholar
    There is no corresponding record for this reference.
  61. 61
    Jang, Y.; Jang, J.; Kim, B. Y.; Song, Y. S.; Lee, D. Y. Effect of Gelatin Content on Degradation Behavior of PLLA/Gelatin Hybrid Membranes. Tissue Eng. Regener. Med. 2024, 21, 557– 569,  DOI: 10.1007/s13770-024-00626-4
    Google Scholar
    There is no corresponding record for this reference.
  62. 62
    Hotta, K.; Behnke, B. J.; Masamoto, K.; Shimotsu, R.; Onodera, N.; Yamaguchi, A.; Poole, D. C.; Kano, Y. Microvascular permeability of skeletal muscle after eccentric contraction-induced muscle injury: in vivo imaging using two-photon laser scanning microscopy. J. Appl. Physiol. 2018, 125, 369– 380,  DOI: 10.1152/japplphysiol.00046.2018
    Google Scholar
    There is no corresponding record for this reference.

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  • Abstract

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    Figure 1

    Figure 1. (a) Schematic image of the electrospinning setup. (b) Mechanical bioreactor with electrospun scaffolds. (c,d) Software setup for mechanical stimulation.

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    Figure 2

    Figure 2. Water contact angle of the nanofiber scaffolds with (A) random and (D) aligned orientation and SEM imaging at different magnifications (1000× and 4000×) of the nanofiber scaffold with a random (B,C, respectively) and aligned orientation (E,F, respectively).

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    Figure 3

    Figure 3. Viability of electrospun scaffolds at day 14: control random scaffolds (a), control aligned scaffolds (b), mechanically stimulated random scaffolds (c), mechanically stimulated aligned scaffolds (d), and viability (e) (scale bar: 200 μm).

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    Figure 4

    Figure 4. Immunostaining of myotubes after day 14. Blue: nucleus. Red: actin. Control random scaffolds 10X (a), control random scaffolds 40X (b), control aligned scaffolds 10X (c), control aligned scaffolds 40X (d), mechanical stimulated random scaffolds 10X (e), mechanical stimulated random scaffolds 40X (f), mechanical stimulated aligned scaffolds 10X (g), and mechanical stimulated aligned scaffolds 40X (h).

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    Figure 5

    Figure 5. Myotube alignment at day 14. Control random scaffolds (a), control aligned scaffolds (b), mechanical stimulated random scaffolds (c), and mechanical stimulated aligned scaffolds (d).

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    Figure 6

    Figure 6. Analysis of myofibers at day 14. Actin fiber alignment (a), actin fiber width (b), fusion index (c), aspect ratio (d), and circularity (e).

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    Figure 7

    Figure 7. Functionality assay measured by cellular luminescence due to calcium transients at day 14 after stimulation with high potassium solution. Control random scaffolds (a), control aligned scaffolds (b), mechanically stimulated random scaffolds (c), mechanically stimulated aligned scaffolds (d), and electrical stimulation of mechanical stimulated aligned scaffolds (e).

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  • References

    This article references 62 other publications.

    1. 1
      Frontera, W. R.; Ochala, J. Skeletal Muscle: A Brief Review of Structure and Function. Calcif. Tissue Int. 2015, 96, 183– 195,  DOI: 10.1007/s00223-014-9915-y
      1
      Skeletal Muscle: A Brief Review of Structure and Function
      Frontera, Walter R.; Ochala, Julien
      Calcified Tissue International (2015), 96 (3), 183-195CODEN: CTINDZ; ISSN:0171-967X. (Springer)
      Skeletal muscle is one of the most dynamic and plastic tissues of the human body. In humans, skeletal muscle comprises approx. 40 % of total body wt. and contains 50-75 % of all body proteins. In general, muscle mass depends on the balance between protein synthesis and degrdn. and both processes are sensitive to factors such as nutritional status, hormonal balance, phys. activity/exercise, and injury or disease, among others. In this review, we discuss the various domains of muscle structure and function including its cytoskeletal architecture, excitation-contraction coupling, energy metab., and force and power generation. We will limit the discussion to human skeletal muscle and emphasize recent scientific literature on single muscle fibers.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhslahtbvK&md5=f06712f45f49f6e4f0c83347fbccb937
    2. 2
      Sabetkish, S.; Currie, P.; Meagher, L. Recent trends in 3D bioprinting technology for skeletal muscle regeneration. Acta Biomater. 2024, 181, 46– 66,  DOI: 10.1016/j.actbio.2024.04.038
      There is no corresponding record for this reference.
    3. 3
      Nakayama, K. H.; Shayan, M.; Huang, N. F. Engineering Biomimetic Materials for Skeletal Muscle Repair and Regeneration. Adv. Healthcare Mater. 2019, 8, 1801168,  DOI: 10.1002/adhm.201801168
      There is no corresponding record for this reference.
    4. 4
      Mihaly, E.; Altamirano, D. E.; Tuffaha, S.; Grayson, W. Engineering skeletal muscle: Building complexity to achieve functionality. Semin. Cell Dev. Biol. 2021, 119, 61– 69,  DOI: 10.1016/j.semcdb.2021.04.016
      There is no corresponding record for this reference.
    5. 5
      Luo, W.; Zhang, H.; Wan, R.; Cai, Y.; Liu, Y.; Wu, Y.; Yang, Y.; Chen, J.; Zhang, D.; Luo, Z. Biomaterials-Based Technologies in Skeletal Muscle Tissue Engineering. Adv. Healthcare Mater. 2024, 13, e2304196  DOI: 10.1002/adhm.202304196
      There is no corresponding record for this reference.
    6. 6
      Martins, A. L. L.; Giorno, L. P.; Santos, A. R. Tissue Engineering Applied to Skeletal Muscle: Strategies and Perspectives. Bioengineering 2022, 9, 744,  DOI: 10.3390/bioengineering9120744
      There is no corresponding record for this reference.
    7. 7
      Mondal, D.; Tiwari, A. Electrospun Nanomatrix for Tissue Regeneration. In Biomedical materials and diagonostic devices; John Wiley & Sons, 2012; pp 561– 580.
      There is no corresponding record for this reference.
    8. 8
      Gouveia, P. J.; Hodgkinson, T.; Amado, I.; Sadowska, J. M.; Ryan, A. J.; Romanazzo, S.; Carroll, S.; Cryan, S. A.; Kelly, D. J.; O’Brien, F. J. Development of collagen-poly(caprolactone)-based core-shell scaffolds supplemented with proteoglycans and glycosaminoglycans for ligament repair. Mater. Sci. Eng., C 2021, 120, 111657,  DOI: 10.1016/j.msec.2020.111657
      There is no corresponding record for this reference.
    9. 9
      Malinauskas, M.; Jankauskaite, L.; Aukstikalne, L.; Dabasinskaite, L.; Rimkunas, A.; Mickevicius, T.; Pockevicius, A.; Krugly, E.; Martuzevicius, D.; Ciuzas, D. Cartilage regeneration using improved surface electrospun bilayer polycaprolactone scaffolds loaded with transforming growth factor-beta 3 and rabbit muscle-derived stem cells. Front. Bioeng. Biotechnol. 2022, 10, 971294,  DOI: 10.3389/fbioe.2022.971294
      There is no corresponding record for this reference.
    10. 10
      Rahmati, M.; Mills, D. K.; Urbanska, A. M.; Saeb, M. R.; Venugopal, J. R.; Ramakrishna, S.; Mozafari, M. Electrospinning for tissue engineering applications. Prog. Mater. Sci. 2021, 117, 100721,  DOI: 10.1016/j.pmatsci.2020.100721
      10
      Electrospinning for tissue engineering applications
      Rahmati, Maryam; Mills, David K.; Urbanska, Aleksandra M.; Saeb, Mohammad Reza; Venugopal, Jayarama Reddy; Ramakrishna, Seeram; Mozafari, Masoud
      Progress in Materials Science (2021), 117 (), 100721CODEN: PRMSAQ; ISSN:0079-6425. (Elsevier Ltd.)
      A review. Tissue engineering makes use of the principles of medicine, biol. and engineering and integrates them into the design of biol. substitutes to restore, maintain and improve the functions of tissue. To fabricate a functional tissue, the engineered structures have to be able to mimic the extracellular matrix (ECM), provide the tissue with oxygen and nutrient circulation as well as remove metabolic wastes in the period of tissue regeneration. Continued efforts have been made in order to fabricate advanced functional three-dimensional scaffolds for tissue engineering. Electrospinning has been recognized and served as one of the most useful techniques based on the resemblance between electrospun fibers and the native tissues. Over the past few decades, a bewildering variety of nanofibrous scaffolds have been developed for various biomedical applications, such as tissue regeneration and therapeutic agent delivery. The present review aims to provide with researchers an in-depth understanding of the promising role and the practical region of applicability of electrospinning in tissue engineering and regenerative medicine by highlighting the outcomes of the most recent studies performed in this field. We address the current strategies used for improving the physicochem. interactions between the cells and the nanofibrous surface. We also discuss the progress and challenges assocd. with the use of electrospinning for tissue engineering and regenerative medicine applications.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BB3cXit1Wms7bO&md5=b6c33bd8dd7aa8f3b469d1e99bbbf654
    11. 11
      Jin, G.; He, R.; Sha, B.; Li, W.; Qing, H.; Teng, R.; Xu, F. Electrospun three-dimensional aligned nanofibrous scaffolds for tissue engineering. Mater. Sci. Eng., C 2018, 92, 995– 1005,  DOI: 10.1016/j.msec.2018.06.065
      11
      Electrospun three-dimensional aligned nanofibrous scaffolds for tissue engineering
      Jin, Guorui; He, Rongyan; Sha, Baoyong; Li, Wenfang; Qing, Huaibin; Teng, Rui; Xu, Feng
      Materials Science & Engineering, C: Materials for Biological Applications (2018), 92 (), 995-1005CODEN: MSCEEE; ISSN:0928-4931. (Elsevier B.V.)
      A review. Engineered tissue constructs rely on biomaterials as support structures for tissue repair and regeneration. Among these biomaterials, polyester biomaterials have been widely used for scaffold construction because of their merits such as ease in synthesis, degradable properties, and elastomeric characteristics. To mimic the aligned structures of native extracellular matrix (ECM) in tissues such as nerve, heart and tendon, various polyester materials have been fabricated into aligned fibrous scaffolds with fibers ranging from several nanometers to several micrometers in diam. by electrospinning in a simple and reproducible manner. These aligned fibrous scaffolds, esp. the three-dimensional (3D) aligned nanofibrous scaffolds have emerged as a promising soln. for tissue regeneration. Compared with two-dimensional (2D) scaffolds, the 3D aligned nanofibrous scaffolds provide another dimension for cell behaviors such as morphogenesis, migration and cell-cell interactions, which is important in regulating the stem cell fate and tissue regeneration. In this review, we provide an extensive overview on recent efforts for constructing 3D aligned polyester nanofibrous scaffolds by electrospinning, then the results of cell-specific functions dependent on such phys. and chem. cues, and discuss their potentials in improving or restoring damaged tissues.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhtlajt7jK&md5=a7d20e1c93dbb3b33fb814728de41a90
    12. 12
      Xue, J.; Wu, T.; Dai, Y.; Xia, Y. Electrospinning and Electrospun Nanofibers: Methods, Materials, and Applications. Chem. Rev. 2019, 119, 5298– 5415,  DOI: 10.1021/acs.chemrev.8b00593
      12
      Electrospinning and Electrospun Nanofibers: Methods, Materials, and Applications
      Xue, Jiajia; Wu, Tong; Dai, Yunqian; Xia, Younan
      Chemical Reviews (Washington, DC, United States) (2019), 119 (8), 5298-5415CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)
      A review. Electrospinning is a versatile and viable technique for generating ultrathin fibers. Remarkable progress has been made with regard to the development of electrospinning methods and engineering of electrospun nanofibers to suit or enable various applications. We aim to provide a comprehensive overview of electrospinning, including the principle, methods, materials, and applications. We begin with a brief introduction to the early history of electrospinning, followed by discussion of its principle and typical app. We then discuss its renaissance over the past two decades as a powerful technol. for the prodn. of nanofibers with diversified compns., structures, and properties. Afterward, we discuss the applications of electrospun nanofibers, including their use as "smart" mats, filtration membranes, catalytic supports, energy harvesting/conversion/storage components, and photonic and electronic devices, as well as biomedical scaffolds. We highlight the most relevant and recent advances related to the applications of electrospun nanofibers by focusing on the most representative examples. We also offer perspectives on the challenges, opportunities, and new directions for future development. At the end, we discuss approaches to the scale-up prodn. of electrospun nanofibers and briefly discuss various types of com. products based on electrospun nanofibers that have found widespread use in our everyday life.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1MXlvVGmt78%253D&md5=9c35e358c32fdb594d8fa0deada780f2
    13. 13
      Choi, J. S.; Lee, S. J.; Christ, G. J.; Atala, A.; Yoo, J. J. The influence of electrospun aligned poly(ε-caprolactone)/collagen nanofiber meshes on the formation of self-aligned skeletal muscle myotubes. Biomaterials 2008, 29, 2899– 2906,  DOI: 10.1016/j.biomaterials.2008.03.031
      13
      The influence of electrospun aligned poly(.vepsiln.-caprolactone)/collagen nanofiber meshes on the formation of self-aligned skeletal muscle myotubes
      Choi, Jin San; Lee, Sang Jin; Christ, George J.; Atala, Anthony; Yoo, James J.
      Biomaterials (2008), 29 (19), 2899-2906CODEN: BIMADU; ISSN:0142-9612. (Elsevier Ltd.)
      Current treatment options for restoring large skeletal muscle tissue defects due to trauma or tumor ablation are limited by the host muscle tissue availability and donor site morbidity of muscle flap implantation. Creation of implantable functional muscle tissue that could restore muscle defects may be a possible soln. To engineer functional muscle tissue for reconstruction, scaffolds that mimic native fibers need to be developed. In this study the authors examd. the feasibility of using poly(ε-caprolactone) (PCL)/collagen based nanofibers using electrospinning as a scaffold system for implantable engineered muscle. The authors investigated whether electrospun nanofibers could guide morphogenesis of skeletal muscle cells and enhance cellular organization. Nanofibers with different fiber orientations were fabricated by electrospinning with a blend of PCL and collagen. Human skeletal muscle cells (hSkMCs) were seeded onto the electrospun PCL/collagen nanofiber meshes and analyzed for cell adhesion, proliferation and organization. The results show that unidirectionally oriented nanofibers significantly induced muscle cell alignment and myotube formation as compared to randomly oriented nanofibers. The aligned composite nanofiber scaffolds seeded with skeletal muscle cells may provide implantable functional muscle tissues for patients with large muscle defects.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1cXlsV2mtbg%253D&md5=caa6a4203c55edc229099ab246af08b8
    14. 14
      Abarzúa-Illanes, P. N.; Padilla, C.; Ramos, A.; Isaacs, M.; Ramos-Grez, J.; Olguín, H. C.; Valenzuela, L. M. Improving myoblast differentiation on electrospun poly(ε-caprolactone) scaffolds. J. Biomed. Mater. Res., Part A 2017, 105, 2241– 2251,  DOI: 10.1002/jbm.a.36091
      14
      Improving myoblast differentiation on electrospun poly(ε-caprolactone) scaffolds
      Abarzua-Illanes, Phammela N.; Padilla, Cristina; Ramos, Andrea; Isaacs, Mauricio; Ramos-Grez, Jorge; Olguin, Hugo C.; Valenzuela, Loreto M.
      Journal of Biomedical Materials Research, Part A (2017), 105 (8), 2241-2251CODEN: JBMRCH; ISSN:1549-3296. (John Wiley & Sons, Inc.)
      Polymer scaffolds are used as an alternative to support tissue regeneration when it does not occur on its own. Cell response on polymer scaffolds is detd. by factors such as polymer compn., topol., and the presence of other mols. We evaluated the cellular response of murine skeletal muscle myoblasts on aligned or unaligned fibers obtained by electrospinning poly(ε-caprolactone) (PCL), and blends with poly(lactic-co-glycolic acid) (PLGA) or decorin, a proteoglycan known to regulate myogenesis. The results showed that aligned PCL fibers with higher content of PLGA promote cell growth and improve the quality of differentiation with PLGA scaffolds having the highest confluence at over 68% of coverage per field of view for myoblasts and more than 7% of coverage for myotubes. At the same time, the addn. of decorin greatly improves the quantity and quality of differentiated cells in terms of cell fusion, myotube length and thickness, being 71, 10, and 51% greater than without the protein, resp. Interestingly, our results suggest that at certain concns., the effect of decorin on myoblast differentiation exceeds the topol. effect of fiber alignment. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2017.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXnslOns74%253D&md5=181c7e8dfe5f737d0eb2759133ba28a3
    15. 15
      Martins, P. M.; Ribeiro, S.; Rebeiro, C.; Sencadas, V.; Gomes, A. C.; Gama, F. M.; Lanceros-Mendez, S. Effect of poling state and morphology of piezoelectric poly(vinylidene fluoride) membranes for skeletal muscle tissue engineering. RSC Adv. 2013, 3, 17938,  DOI: 10.1039/C3RA43499K
      There is no corresponding record for this reference.
    16. 16
      Aviss, K. J.; Gough, J. E.; Downes, S. Aligned electrospun polymer fibres for skeletal muscle regeneration. Eur. Cells Mater. 2010, 19, 193– 204,  DOI: 10.22203/eCM.v019a19
      16
      Aligned electrospun polymer fibers for skeletal muscle regeneration
      Aviss, K. J.; Gough, J. E.; Downes, S.
      European Cells and Materials (2010), 19 (), 193-204CODEN: ECMUBB; ISSN:1473-2262. (AO Research Institute Davos)
      Skeletal muscle repair is often overlooked in surgical procedures and in serious burn victims. Creating a tissue-engineered skeletal muscle would not only provide a grafting material for these clin. situations, but could also be used as a valuable true-to-life research tool into diseases affecting muscle tissue. Electrospinning of the elastomer PLGA produced aligned fibers that had the correct topol. to provide contact guidance for myoblast elongation and alignment. In addn., the electrospun scaffold required no surface modifications or incorporation of biol. material for adhesion, elongation, and differentiation of C2C12 murine myoblasts.
      >> More from SciFinder ®
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    17. 17
      Aguirre-Chagala, Y. E.; Altuzar, V.; León-Sarabia, E.; Tinoco-Magaña, J. C.; Yañez-Limón, J. M.; Mendoza-Barrera, C. Physicochemical properties of polycaprolactone/collagen/elastin nanofibers fabricated by electrospinning. Mater. Sci. Eng., C 2017, 76, 897– 907,  DOI: 10.1016/j.msec.2017.03.118
      17
      Physicochemical properties of polycaprolactone/collagen/elastin nanofibers fabricated by electrospinning
      Aguirre-Chagala, Yanet E.; Altuzar, Victor; Leon-Sarabia, Eleazar; Tinoco-Magana, Julio C.; Yanez-Limon, Jose M.; Mendoza-Barrera, Claudia
      Materials Science & Engineering, C: Materials for Biological Applications (2017), 76 (), 897-907CODEN: MSCEEE; ISSN:0928-4931. (Elsevier B.V.)
      Collagen and elastin are the two most abundant proteins in the human body, and as biomaterials offer fascinating properties to composite materials. More detailed investigations including these biomaterials within reinforced composites are still needed. This report describes physicochem. properties of fibers composed of collagen type I, collagen III, elastin and polycaprolactone (PCL). Prior to the electrospinning process, PCL was functionalized through covalent attachment of -NH2 groups by aminolysis reaction with hexamentilendiamine. The fibers were fabricated by electrospinning technique set up with a non-conventional collector. A morphol. comparative study was developed at different rations of collagen type I, observing in some cases two populations of fibers. The diams. and morphol. were analyzed by SEM, observing a wide array of nanostructures with diams. of ∼ 310 to 693 nm. Chem. characterization was assessed by FT-IR spectroscopy and the functionalized PCL was characterized through ninhydrin assay resulting in 0.36 mM NH2/mg fiber. Swelling tests were performed for 24 h, obtaining 320% for the majority of the fibers indicating morphol. stability and good water uptake. In addn., contact angle anal. demonstrated adequate permeability and differences for each system depending mainly upon the type of biopolymer incorporated and the functionalization of PCL, ranging the values from 108° to 17°. Moreover, differential scanning calorimetry results showed a melting temp. (Tm) of ∼ 60°C. The onset degrdn. temps. (Td,onset) ranged between 115 and 148°C, and were obtained by thermogravimetric anal. The local mech. properties of individual fibers were quantified by at. force acoustic microscopy. These results propose that the physicochem. and mech. properties of these scaffolds offer the possibility for enhanced biol. activity Thus, they have a great potential as candidate scaffolds in tissue engineering applications.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXlt12ht7s%253D&md5=8fe55e3dcbbe37ea3ab7a5c4b9d4107d
    18. 18
      Annabi, N.; Fathi, A.; Mithieux, S. M.; Weiss, A. S.; Dehghani, F. Fabrication of porous PCL/elastin composite scaffolds for tissue engineering applications. J. Supercrit. Fluids 2011, 59, 157– 167,  DOI: 10.1016/j.supflu.2011.06.010
      18
      Fabrication of porous PCL/elastin composite scaffolds for tissue engineering applications
      Annabi, Nasim; Fathi, Ali; Mithieux, Suzanne M.; Weiss, Anthony S.; Dehghani, Fariba
      Journal of Supercritical Fluids (2011), 59 (), 157-167CODEN: JSFLEH; ISSN:0896-8446. (Elsevier B.V.)
      The authors present the development of a technique that enables the fabrication of 3-dimensional (3D) porous poly(.vepsiln.-caprolactone) (PCL)/elastin composites. High pressure CO2 was used as a foaming agent to create large pores in a PCL matrix and impregnate elastin into the 3D structure of the scaffold. The effects of process variables such as temp., pressure, processing time, depressurization rate, and salt concn. on the characteristics of PCL scaffolds were detd. Scaffolds with av. pore sizes of 540 μm and porosity of 91% were produced using CO2 at 65 bar, 70 °C, processing time of 1 h, depressurization rate of 15 bar/min, and addn. of 30 wt% salt particles. The PCL/elastin composites were then prepd. under different conditions: ambient pressure, vacuum, and high pressure CO2. The fabrication of composites under vacuum resulted in the formation of nonhomogenous scaffolds. However, uniform 3D composites were formed when using high pressure CO2 at 37 °C and 60 bar.
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    19. 19
      Sant, S.; Hwang, C. M.; Lee, S.-H.; Khademhosseini, A. Hybrid PGS-PCL microfibrous scaffolds with improved mechanical and biological properties. J. Tissue Eng. Regener. Med. 2011, 5, 283– 291,  DOI: 10.1002/term.313
      19
      Hybrid PGS-PCL microfibrous scaffolds with improved mechanical and biological properties
      Sant, Shilpa; Hwang, Chang Mo; Lee, Sang-Hoon; Khademhosseini, Ali
      Journal of Tissue Engineering and Regenerative Medicine (2011), 5 (4), 283-291CODEN: JTERAX; ISSN:1932-6254. (Wiley-Blackwell)
      Poly(glycerol sebacate) (PGS) is a biodegradable elastomer that has generated great interest as a scaffold material due to its desirable mech. properties. However, the use of PGS in tissue engineering is limited by difficulties in casting micro- and nanofibrous structures, due to high temps. and vacuum required for its curing and limited soly. of the cured polymer. In this paper, we developed microfibrous scaffolds made from blends of PGS and poly(ε-caprolactone) (PCL) using a std. electrospinning set-up. At a given PGS : PCL ratio, higher voltage resulted in significantly smaller fiber diams. (reduced from ∼4 μm to 2.8 μm; p < 0.05). Further increase in voltage resulted in the fusion of fibers. Similarly, higher PGS concns. in the polymer blend resulted in significantly increased fiber diam. (p < 0.01). We further compared the mech. properties of electrospun PGS : PCL scaffolds with those made from PCL. Scaffolds with higher PGS concns. showed higher elastic modulus (EM), ultimate tensile strength (UTS) and ultimate elongation (UE) (p < 0.01) without the need for thermal curing or photocrosslinking. Biol. evaluation of these scaffolds showed significantly improved HUVEC attachment and proliferation compared to PCL-only scaffolds (p < 0.05). Thus, we have demonstrated that simple blends of PGS prepolymer with PCL can be used to fabricate microfibrous scaffolds with mech. properties in the range of a human aortic valve leaflet.
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    20. 20
      Ren, K.; Wang, Y.; Sun, T.; Yue, W.; Zhang, H. Electrospun PCL/gelatin composite nanofiber structures for effective guided bone regeneration membranes. Mater. Sci. Eng., C 2017, 78, 324– 332,  DOI: 10.1016/j.msec.2017.04.084
      20
      Electrospun PCL/gelatin composite nanofiber structures for effective guided bone regeneration membranes
      Ren, Ke; Wang, Yi; Sun, Tao; Yue, Wen; Zhang, Hongyu
      Materials Science & Engineering, C: Materials for Biological Applications (2017), 78 (), 324-332CODEN: MSCEEE; ISSN:0928-4931. (Elsevier B.V.)
      Guided bone regeneration (GBR) membranes have been proved of great benefit for bone tissue engineering due to the improvement of cell attachment and proliferation. To develop GBR membranes with better biocompatibility and more proper degrdn. ability, here we fabricated polycaprolactone (PCL, polymer)/gelatin (protein) hybrid nanofibrous GBR membranes via electrospinning, followed by crosslinking with genipin. Acetic acid (HAc) was utilized to resolve the phase sepn. of PCL and gelatin, therefore homogeneous PCL/gelatin hybrid nanofibers with different ratios were successfully prepd. FTIR, XPS, TGA, DSC results proved that the proportion of PCL and gelatin in the as-spun nanofiber membranes could be simply adjusted by changing the wt. ratio of PCL and gelatin in the spinning soln. SEM and AFM images demonstrated that all the nanofibers possessed uniform and smooth structures both in two dimension (2D) and three dimension (3D). The mech. tests showed that these nanofibers exhibited appropriate tensile and strength properties, which were suitable for bone tissue engineering. CCK-8 and SEM images revealed that all the membranes were biocompatible to MC3T3-e1 cells. In addn., the in vitro osteogenesis characterizations, alizarin red in normal medium and osteogenesis medium, indicated that the nanofibers could promote bone formation. Therefore, all these results could suggest that our design of electrospun polymer/protein nanofiber membranes was effective for guided bone regeneration.
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    21. 21
      Wu, X.; Ni, S.; Dai, T.; Li, J.; Shao, F.; Liu, C.; Wang, J.; Fan, S.; Tan, Y.; Zhang, L. Biomineralized tetramethylpyrazine-loaded PCL/gelatin nanofibrous membrane promotes vascularization and bone regeneration of rat cranium defects. J. Nanobiotechnol. 2023, 21, 423,  DOI: 10.1186/s12951-023-02155-z
      There is no corresponding record for this reference.
    22. 22
      Hsu, R.-S.; Chen, P.; Fang, J.; Chen, Y.; Chang, C.; Lu, Y.; Hu, S. Adaptable Microporous Hydrogels of Propagating NGF-Gradient by Injectable Building Blocks for Accelerated Axonal Outgrowth. Adv. Sci. 2019, 6, 1900520,  DOI: 10.1002/advs.201900520
      22
      Adaptable Microporous Hydrogels of Propagating NGF-Gradient by Injectable Building Blocks for Accelerated Axonal Outgrowth
      Hsu Ru-Siou; Chen Pei-Yueh; Fang Jen-Hung; Chang Chien-Wen; Hu Shang-Hsiu; Chen You-Yin; Lu Yu-Jen
      Advanced science (Weinheim, Baden-Wurttemberg, Germany) (2019), 6 (16), 1900520 ISSN:2198-3844.
      Injectable hydrogels in regeneration medicine can potentially mimic hierarchical natural living tissue and fill complexly shaped defects with minimally invasive implantation procedures. To achieve this goal, however, the versatile hydrogels that usually possess the nonporous structure and uncontrollable spatial agent release must overcome the difficulties in low cell-penetrative rates of tissue regeneration. In this study, an adaptable microporous hydrogel (AMH) composed of microsized building blocks with opposite charges serves as an injectable matrix with interconnected pores and propagates gradient growth factor for spontaneous assembly into a complex shape in real time. By embedding gradient concentrations of growth factors into the building blocks, the propagated gradient of the nerve growth factor, integrated to the cell-penetrative connected pores constructed by the building blocks in the nerve conduit, effectively promotes cell migration and induces dramatic bridging effects on peripheral nerve defects, achieving axon outgrowth of up to 4.7 mm and twofold axon fiber intensity in 4 days in vivo. Such AMHs with intrinsic properties of tunable mechanical properties, gradient propagation of biocues and effective induction of cell migration are potentially able to overcome the limitations of hydrogel-mediated tissue regeneration in general and can possibly be used in clinical applications.
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    23. 23
      Echave, M. C.; Burgo, L. S.; Pedraz, J. L.; Orive, G. Gelatin as Biomaterial for Tissue Engineering. Curr. Pharm. Des. 2017, 23, 3567– 3584,  DOI: 10.2174/0929867324666170511123101
      23
      Gelatin as Biomaterial for Tissue Engineering
      Echave, Mari C.; Burgo, Laura S.; Pedraz, Jose L.; Orive, Gorka
      Current Pharmaceutical Design (2017), 23 (24), 3567-3584CODEN: CPDEFP; ISSN:1381-6128. (Bentham Science Publishers Ltd.)
      A review. Tissue engineering is considered one of the most important therapeutic strategies of regenerative medicine. The main objective of these new technologies is the development of substitutes made with biomaterials that are able to heal, repair or regenerate injured or diseased tissues and organs. These constructs seek to unlock the limited ability of human tissues and organs to regenerate. In this review, we highlight the convenient intrinsic properties of gelatin for the design and development of advanced systems for tissue engineering. Gelatin is a natural origin protein derived from collagen hydrolysis. We outline herein a state of the art of gelatin-based composites in order to overcome limitations of this polymeric material and modulate the properties of the formulations. Control release of bioactive mols., formulations with conductive properties or systems with improved mech. properties can be obtained using gelatin composites. Many studies have found that the use of calcium phosphate ceramics and diverse synthetic polymers in combination with gelatin improve the mech. properties of the structures. On the other hand, polyaniline and carbon-based nanosubstrates are interesting mols. to provide gelatin-based systems with conductive properties, esp. for cardiac and nerve tissue engineering. Finally, this review provides an overview of the different types of gelatin-based structures including nanoparticles, microparticles, 3D scaffolds, electrospun nanofibers and in situ gelling formulations. Thanks to the significant progress that has already been made, along with others that will be achieved in a near future, the safe and effective clin. implementation of gelatin-based products is expected to accelerate and expand shortly.
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    24. 24
      Perez-puyana, V.; Villanueva, P.; Jiménez-rosado, M.; de la Portilla, F.; Romero, A. Incorporation of elastin to improve polycaprolactone-based scaffolds for skeletal muscle via electrospinning. Polymers 2021, 13, 1501,  DOI: 10.3390/polym13091501
      24
      Incorporation of elastin to improve polycaprolactone-based scaffolds for skeletal muscle via electrospinning
      Perez-Puyana, Victor; Villanueva, Paula; Jimenez-Rosado, Mercedes; De La Portilla, Fernando; Romero, Alberto
      Polymers (Basel, Switzerland) (2021), 13 (9), 1501CODEN: POLYCK; ISSN:2073-4360. (MDPI AG)
      Skeletal muscle regeneration is increasingly necessary, which is reflected in the increasing no. of studies that are focused on improving the scaffolds used for such regeneration, as well as the incubation protocol. The main objective of this work was to improve the characteristics of polycaprolactone (PCL) scaffolds by incorporating elastin to achieve better cell proliferation and biocompatibility. In addn., two cell incubation protocols (with and without dynamic mech. stimulation) were evaluated to improve the activity and functionality yields of the regenerated cells. The results indicate that the incorporation of elastin generates aligned and more hydrophilic scaffolds with smaller fiber size. In addn., the mech. properties of the resulting scaffolds make them adequate for use in both bioreactors and patients. All these characteristics increase the biocompatibility of these systems, generating a better interconnection with the tissue. However, due to the low maturation achieved in biol. tests, no differences could be found between the incubation with and without dynamic mech. stimulation.
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    25. 25
      Perez-Puyana, V.; Wieringa, P.; Yuste, Y.; de la Portilla, F.; Guererro, A.; Romero, A.; Moroni, L. Fabrication of hybrid scaffolds obtained from combinations of PCL with gelatin or collagen via electrospinning for skeletal muscle tissue engineering. J. Biomed. Mater. Res., Part A 2021, 109, 1600– 1612,  DOI: 10.1002/jbm.a.37156
      There is no corresponding record for this reference.
    26. 26
      Thangadurai, M.; Srinivasan, S. S.; Sekar, M. P.; Sethuraman, S.; Sundaramurthi, D. Emerging perspectives on 3D printed bioreactors for clinical translation of engineered and bioprinted tissue constructs. J. Mater. Chem. B 2024, 12, 350– 381,  DOI: 10.1039/D3TB01847D
      There is no corresponding record for this reference.
    27. 27
      Ravichandran, A.; Liu, Y.; Teoh, S. H. Review: bioreactor design towards generation of relevant engineered tissues: focus on clinical translation. J. Tissue Eng. Regener. Med. 2018, 12, e7– e22,  DOI: 10.1002/term.2270
      There is no corresponding record for this reference.
    28. 28
      Pennisi, C. P.; Olesen, C. G.; de Zee, M.; Rasmussen, J.; Zachar, V. Uniaxial Cyclic Strain Drives Assembly and Differentiation of Skeletal Myocytes. Tissue Eng., Part A 2011, 17, 2543– 2550,  DOI: 10.1089/ten.tea.2011.0089
      28
      Uniaxial cyclic strain drives assembly and differentiation of skeletal myocytes
      Pennisi Cristian Pablo; Olesen Christian Gammelgaard; de Zee Mark; Rasmussen John; Zachar Vladimir
      Tissue engineering. Part A (2011), 17 (19-20), 2543-50 ISSN:.
      Ex vivo engineering of skeletal muscle represents an exciting new area of biotechnology. Although the ability of skeletal muscle cells to sense and respond to mechanical forces is well known, strategies based on the use of mechanical stimuli to optimize myogenesis in vitro remain limited. In this work, we describe a simple but powerful method based on uniaxial cyclic tensile strain (CTS) to induce assembly and differentiation of skeletal myocytes in vitro. Confluent mouse myoblastic precursors cultured on flexible-bottomed culture plates were subjected to either uniaxial or equibiaxial CTS. The uniaxial CTS protocol resulted in a highly aligned array of cross-striated fibers, with the major axis of most cells aligned perpendicularly to the axis of strain. In addition, a short period of myogenin activation and significant increase in the myotube/myoblast ratio and percentage of myosin-positive myotubes was found, indicating an enhanced cell differentiation. In contrast, cells under equibiaxial strain regimen had no clear orientation and displayed signs of membrane damage and impaired differentiation. These results, thus, demonstrate that the selection of a proper paradigm is a key element when discussing the relevance of mechanical stimulation for myogenesis in vitro. This study provides a rational framework to optimize engineering of functional skeletal muscle.
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    29. 29
      Liao, I.-C.; Liu, J. B.; Bursac, N.; Leong, K. W. Effect of Electromechanical Stimulation on the Maturation of Myotubes on Aligned Electrospun Fibers. Cell. Mol. Bioeng. 2008, 1, 133– 145,  DOI: 10.1007/s12195-008-0021-y
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      Effect of electrochemical stimulation on the maturation of myotubes on aligned electrospun fibers
      Liao, I.-Chien; Liu, Jason B.; Bursac, Nenad; Leong, Kam W.
      Cellular and Molecular Bioengineering (2008), 1 (2-3), 133-145CODEN: CMBECP; ISSN:1865-5025. (Springer)
      Tissue engineering may provide an alternative to cell injection as a therapeutic soln. for myocardial infarction. A tissue-engineered muscle patch may offer better host integration and higher functional performance. This study examd. the differentiation of skeletal myoblasts on aligned electrospun polyurethane (PU) fibers and in the presence of electromech. stimulation. Skeletal myoblasts cultured on aligned PU fibers showed more pronounced elongation, better alignment, higher level of transient receptor potential cation channel-1 (TRPC-1) expression, upregulation of contractile proteins and higher percentage of striated myotubes compared to those cultured on random PU fibers and film. The resulting tissue constructs generated tetanus forces of 1.1 mN with a 10-ms time to tetanus. Addnl. mech., elec., or synchronized electromech. stimuli applied to myoblasts cultured on PU fibers increased the percentage of striated myotubes from 70% to 85% under optimal stimulation conditions, which was accompanied by an upregulation of contractile proteins such as α-actinin and myosin heavy chain. In describing how electromech. cues can be combined with topog. cue, this study helped move towards the goal of generating a biomimetic microenvironment for engineering of functional skeletal muscle.
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    30. 30
      Candiani, G.; Riboldi, S. A.; Sadr, N.; Lorenzoni, S.; Neuenschwander, P.; Montevecchi, F. M.; Mantero, S. Cyclic Mechanical Stimulation Favors Myosin Heavy Chain Accumulation in Engineered Skeletal Muscle Constructs. J. Appl. Biomater. Biomech. 2010, 8, 68– 75
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      Cyclic mechanical stimulation favors myosin heavy chain accumulation in engineered skeletal muscle constructs
      Candiani, Gabriele; Riboldi, Stefania A.; Sadr, Nasser; Lorenzoni, Stefano; Neuenschwander, Peter; Montevecchi, Franco M.; Mantero, Sara
      Journal of Applied Biomaterials & Biomechanics (2010), 8 (2), 68-75CODEN: JABBA7; ISSN:1722-6899. (Wichtig Editore)
      Purpose: Since stretching plays a key role in skeletal muscle tissue development in vivo, by making use of an innovative bioreactor and a biodegradable microfibrous scaffold (DegraPol) previously developed by our group, we aimed to investigate the effect of mech. conditioning on the development of skeletal muscle engineered constructs, obtained by seeding and culturing murine skeletal muscle cells on electrospun membranes. Methods: Following 5 days of static culture, skeletal muscle constructs were transferred into the bioreactor and further cultured for 13 days, while experiencing a stretching pattern adapted from the literature to resemble mouse development and growth. Sample withdrawal occurred at the onset of cyclic stretching and after 7 and 10 days. Myosin heavy chain (MHC) accumulation in stretched constructs (D) was evaluated by Western blot anal. and immunofluorescence staining, using statically cultured samples (S) as controls. Results: Western blot anal. of MHC on dynamically (D) and statically (S) cultured constructs at different time points showed that, at day 10, the applied stretching pattern led to an eight-fold increase in myosin accumulation in cyclically stretched constructs (D) with respect to the corresponding static controls (S). These results were confirmed by immunofluorescence staining of total sarcomeric MHC. Conclusions: Since previous attempts to reproduce skeletal myogenesis in vitro mainly suffered from the difficulty of driving myoblast development into an architecturally organized array of myosin expressing myotubes, the chance of inducing MHC accumulation via mech. conditioning represents a significant step towards the generation of a functional muscle construct for skeletal muscle tissue engineering applications.
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    31. 31
      Beldjilali-Labro, M.; Garcia Garcia, A.; Farhat, F.; Bedoui, F.; Grosset, J. F.; Dufresne, M.; Legallais, C. Biomaterials in tendon and skeletal muscle tissue engineering: Current trends and challenges. Materials 2018, 11, 1116,  DOI: 10.3390/ma11071116
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      Biomaterials in tendon and skeletal muscle tissue engineering: current trends and challenges
      Beldjilali-Labro, Megane; Garcia, Alejandro Garcia; Farhat, Firas; Bedoui, Fahmi; Grosset, Jean-Francois; Dufresne, Murielle; Legallais, Cecile
      Materials (2018), 11 (7), 1116/1-1116/49CODEN: MATEG9; ISSN:1996-1944. (MDPI AG)
      Tissue engineering is a promising approach to repair tendon and muscle when natural healing fails. Biohybrid constructs obtained after cells' seeding and culture in dedicated scaffolds have indeed been considered as relevant tools for mimicking native tissue, leading to a better integration in vivo. They can also be employed to perform advanced in vitro studies to model the cell differentiation or regeneration processes. In this review, we report and analyze the different solns. proposed in literature, for the reconstruction of tendon, muscle, and the myotendinous junction. They classically rely on the three pillars of tissue engineering, i.e., cells, biomaterials and environment (both chem. and phys. stimuli). We have chosen to present biomimetic or bioinspired strategies based on understanding of the native tissue structure/functions/properties of the tissue of interest. For each tissue, we sorted the relevant publications according to an increasing degree of complexity in the materials' shape or manuf. We present their biol. and mech. performances, obsd. in vitro and in vivo when available. Although there is no consensus for a gold std. technique to reconstruct these musculo-skeletal tissues, the reader can find different ways to progress in the field and to understand the recent history in the choice of materials, from collagen to polymer-based matrixes.
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    32. 32
      Powell, C. A.; Smiley, B. L.; Mills, J.; Vandenburgh, H. H. Mechanical stimulation improves tissue-engineered human skeletal muscle. Am. J. Physiol. 2002, 283, C1557– C1565,  DOI: 10.1152/ajpcell.00595.2001
      There is no corresponding record for this reference.
    33. 33
      Player, D. J.; Martin, N. R. W.; Passey, S. L.; Sharples, A. P.; Mudera, V.; Lewis, M. P. Acute mechanical overload increases IGF-I and MMP-9 mRNA in 3D tissue-engineered skeletal muscle. Biotechnol. Lett. 2014, 36, 1113– 1124,  DOI: 10.1007/s10529-014-1464-y
      33
      Acute mechanical overload increases IGF-I and MMP-9 mRNA in 3D tissue-engineered skeletal muscle
      Player, D. J.; Martin, N. R. W.; Passey, S. L.; Sharples, A. P.; Mudera, V.; Lewis, M. P.
      Biotechnology Letters (2014), 36 (5), 1113-1124CODEN: BILED3; ISSN:0141-5492. (Springer)
      Skeletal muscle (SkM) is a tissue that responds to mech. load following both physiol. (exercise) or pathophysiol. (bed rest) conditions. The heterogeneity of human samples and the exptl. and ethical limitations of animal studies provide a rationale for the study of SkM plasticity in vitro. Many current in vitro approaches of mech. loading of SkM disregard the three-dimensional (3D) structure in vivo. Tissue engineered 3D SkM, that displays highly aligned and differentiated myotubes, was used to investigate mechano-regulated gene transcription of genes implicated in hypertrophy/atrophy. Static loading (STL) and ramp loading (RPL) at 10 % strain for 60 min were used as mechano-stimulation with constructs sampled immediately for RNA extn. STL increased IGF-I mRNA compared to both RPL and CON (control, p = 0.003 and 0.011 resp.) while MMP-9 mRNA increased in STL and RPL compared to CON (both p < 0.05). IGFBP-2 mRNA was differentially regulated in RPL and STL compared to CON (p = 0.057), while a redn. in IGFBP-5 mRNA was found for STL and RPL compared to CON (both p < 0.05). There was no effect in the expression of putative atrophic genes, myostatin, MuRF-1 and MAFBx (all p > 0.05). These data demonstrate a transcriptional signature assocd. with SkM hypertrophy within a tissue-engineered model that more greatly recapitulates the in vivo SkM structure compared previously published studies.
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    34. 34
      Vandenburgh, H. H.; Hatfaludy, S.; Karlisch, P.; Shansky, J. Skeletal muscle growth is stimulated by intermittent stretch-relaxation in tissue culture. Am. J. Physiol. 1989, 256, C674– C682,  DOI: 10.1152/ajpcell.1989.256.3.C674
      There is no corresponding record for this reference.
    35. 35
      Chen, S.; Li, R.; Li, X.; Xie, J. Electrospinning: An enabling nanotechnology platform for drug delivery and regenerative medicine. Adv. Drug Delivery Rev. 2018, 132, 188– 213,  DOI: 10.1016/j.addr.2018.05.001
      35
      Electrospinning: An enabling nanotechnology platform for drug delivery and regenerative medicine
      Chen, Shixuan; Li, Ruiquan; Li, Xiaoran; Xie, Jingwei
      Advanced Drug Delivery Reviews (2018), 132 (), 188-213CODEN: ADDREP; ISSN:0169-409X. (Elsevier B.V.)
      Electrospinning provides an enabling nanotechnol. platform for generating a rich variety of novel structured materials in many biomedical applications including drug delivery, biosensing, tissue engineering, and regenerative medicine. In this review article, we begin with a thorough discussion on the method of producing 1D, 2D, and 3D electrospun nanofiber materials. In particular, we emphasize on how the 3D printing technol. can contribute to the improvement of traditional electrospinning technol. for the fabrication of 3D electrospun nanofiber materials as drug delivery devices/implants, scaffolds or living tissue constructs. We then highlight several notable examples of electrospun nanofiber materials in specific biomedical applications including cancer therapy, guiding cellular responses, engineering in vitro 3D tissue models, and tissue regeneration. Finally, we finish with conclusions and future perspectives of electrospun nanofiber materials for drug delivery and regenerative medicine.
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    36. 36
      Wang, L.; Wu, Y.; Guo, B.; Ma, P. X. Nanofiber Yarn/Hydrogel Core–Shell Scaffolds Mimicking Native Skeletal Muscle Tissue for Guiding 3D Myoblast Alignment, Elongation, and Differentiation. ACS Nano 2015, 9, 9167– 9179,  DOI: 10.1021/acsnano.5b03644
      36
      Nanofiber Yarn/Hydrogel Core-Shell Scaffolds Mimicking Native Skeletal Muscle Tissue for Guiding 3D Myoblast Alignment, Elongation, and Differentiation
      Wang, Ling; Wu, Yaobin; Guo, Baolin; Ma, Peter X.
      ACS Nano (2015), 9 (9), 9167-9179CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
      Designing scaffolds that can mimic native skeletal muscle tissue and induce 3D cellular alignment and elongated myotube formation remains an ongoing challenge for skeletal muscle tissue engineering. Herein, we present a simple technique to generate core-shell composite scaffolds for mimicking native skeletal muscle structure, which comprise the aligned nanofiber yarn (NFY) core and the photocurable hydrogel shell. The aligned NFYs are prepd. by the hybrid compn. including poly(caprolactone), silk fibroin, and polyaniline via a developed dry-wet electrospinning method. A series of core-shell column and sheet composite scaffolds are ultimately obtained by encapsulating a piece and layers of aligned NFY cores within the hydrogel shell after photo-crosslinking. C2C12 myoblasts are seeded within the core-shell scaffolds, and the good biocompatibility of these scaffolds and their ability to induce 3D cellular alignment and elongation are successfully demonstrated. Furthermore, the 3D elongated myotube formation within core-shell scaffolds is also performed after long-term cultivation. These data suggest that these core-shell scaffolds combine the aligned NFY core that guides the myoblast alignment and differentiation and the hydrogel shell that provides a suitable 3D environment for nutrition exchange and mech. protection to perform a great practical application for skeletal muscle regeneration.
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    37. 37
      Cha, S. H.; Lee, H. J.; Koh, W. G. Study of myoblast differentiation using multi-dimensional scaffolds consisting of nano and micropatterns. Biomater. Res. 2017, 21, 1,  DOI: 10.1186/s40824-016-0087-x
      37
      Study of myoblast differentiation using multi-dimensional scaffolds consisting of nano and micropatterns
      Cha, Sung Ho; Lee, Hyun Jong; Koh, Won-Gun
      Biomaterials Research (2017), 21 (), 1/1-1/9CODEN: BRIEFJ; ISSN:2055-7124. (BioMed Central Ltd.)
      Background: The topog. cue is major influence on skeletal muscle cell culture because the structure is highly organized and consists of long parallel bundles of multinucleated myotubes that are formed by differentiation and fusion of myoblast satellite cells. In this tech. report, we fabricated a multiscale scaffold using electrospinning and poly (ethylene glycol) (PEG) hydrogel micropatterns to monitor the cell behaviors on nano- and micro-alignment combined scaffolds with different combinations of angles. Results: We fabricated multiscale scaffolds that provide biocompatible and extracellular matrix (ECM)-mimetic environments via electrospun nanofiber and PEG hydrogel micro patterning. MTT assays demonstrated an almost four-fold increase in the proliferation rate during the 7 days of cell culture for all of the exptl. groups. Cell orientation and elongation were measured to confirm the myogenic potential. On the aligned fibrous scaffolds, more than 90% of the cells were dispersed±20° of the fiber orientation. To det. cell elongation, we monitored nuclei aspect ratios. On a random nanofiber, the cells demonstrated an aspect ratio of 1.33, but on perpendicular and parallel nanofibers, the aspect ratio was greater than 2. Myosin heavy chain (MHC) expression was significantly higher (i) on parallel compared to random fibers, (ii) the 100 μm compared to the 200 μm line pattern. We confirmed the disparate trends of myotube formation that can be provoked through multi-dimensional scaffolds. Conclusion: We studied more favorable environments that induce cell alignment and elongation for myogenesis by combining nano- and micro-scale patterns. The fabricated system can serve as a novel multi-dimensional platform to study in vitro cell behaviors.
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    38. 38
      Kim, M. S.; Jun, I.; Shin, Y. M.; Jang, W.; Kim, S. I.; Shin, H. The development of genipin-crosslinked poly(caprolactone) (PCL)/gelatin nanofibers for tissue engineering applications. Macromol. Biosci. 2010, 10, 91– 100,  DOI: 10.1002/mabi.200900168
      38
      The Development of Genipin-Crosslinked Poly(caprolactone) (PCL)/Gelatin Nanofibers for Tissue Engineering Applications
      Kim, Min Sup; Jun, Indong; Shin, Young Min; Jang, Wonhee; Kim, Sun I.; Shin, Heungsoo
      Macromolecular Bioscience (2010), 10 (1), 91-100CODEN: MBAIBU; ISSN:1616-5187. (Wiley-VCH Verlag GmbH & Co. KGaA)
      Composite nanofibers of poly(caprolactone) (PCL) and gelatin crosslinked with genipin are prepd. The contact angles and mech. properties of crosslinked PCL-gelatin nanofibers decrease as the gelatin content increases. The proliferation of myoblasts is higher in the crosslinked PCL-gelatin nanofibers than in the PCL nanofibers, and the formation of myotubes is only obsd. on the crosslinked PCL-gelatin nanofibers. The expression level of myogenin, myosin heavy chain, and troponin T genes is increased as the gelatin content is increased. The results suggest that PCL-gelatin nanofibers crosslinked with genipin can be used as a substrate to modulate proliferation and differentiation of myoblasts, presenting potential applications in muscle tissue engineering.
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    39. 39
      Ostrovidov, S.; Shi, X.; Zhang, L.; Liang, X.; Kim, S. B.; Fujie, T.; Ramalingam, M.; Chen, M.; Nakajima, K.; Al-Hazmi, F. Myotube formation on gelatin nanofibers – Multi-walled carbon nanotubes hybrid scaffolds. Biomaterials 2014, 35, 6268– 6277,  DOI: 10.1016/j.biomaterials.2014.04.021
      There is no corresponding record for this reference.
    40. 40
      Drexler, J. W.; Powell, H. M. Regulation of electrospun scaffold stiffness via coaxial core diameter. Acta Biomater. 2011, 7, 1133– 1139,  DOI: 10.1016/j.actbio.2010.10.025
      40
      Regulation of electrospun scaffold stiffness via coaxial core diameter
      Drexler, J. W.; Powell, H. M.
      Acta Biomaterialia (2011), 7 (3), 1133-1139CODEN: ABCICB; ISSN:1742-7061. (Elsevier Ltd.)
      Scaffold mechanics influence cellular behavior, including migration, phenotype and viability. Scaffold stiffness is commonly modulated through crosslinking, polymer d., or bioactive coatings on stiff substrates. These approaches provide useful information about cellular response to substrate stiffness; however, they are not ideal as the processing can change substrate morphol., d. or chem. Coaxial electrospinning was investigated as a fabrication method to produce scaffolds with tunable stiffness and strength without changing architecture or surface chem. Core soln. concn., solvent and feed rate were utilized to control core diam. with higher soln. concn. and feed rate pos. correlating with increased fiber diam. and stiffness. Coaxial scaffolds electrospun with an 8 wt./vol.% polycaprolactone (PCL)-HFP soln. at 1 mL h-1 formed scaffolds with an av. core diam. of 1.1 ± 0.2 μm and stiffness of 0.027 ± 3.3 × 10-3 N mm-1. In contrast, fibers which were 2.6 ± 0.1 μm in core diam. yielded scaffolds with a stiffness of 0.065 ± 4.7 × 10-3 N mm-1. Strength and stiffness pos. correlated with core diam. with no significant difference in total fiber diam. and interfiber distance obsd. in as-spun scaffolds. These data indicate that coaxial core diam. can be utilized to tailor mech. properties of three-dimensional scaffolds and would provide an ideal scaffold for assessing the effect of scaffold mechanics on cell behavior.
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    41. 41
      Wang, L.; Wu, Y.; Guo, B.; Ma, P. X. Nanofiber Yarn/Hydrogel Core–Shell Scaffolds Mimicking Native Skeletal Muscle Tissue for Guiding 3D Myoblast Alignment, Elongation, and Differentiation. ACS Nano 2015, 9, 9167– 9179,  DOI: 10.1021/acsnano.5b03644
      41
      Nanofiber Yarn/Hydrogel Core-Shell Scaffolds Mimicking Native Skeletal Muscle Tissue for Guiding 3D Myoblast Alignment, Elongation, and Differentiation
      Wang, Ling; Wu, Yaobin; Guo, Baolin; Ma, Peter X.
      ACS Nano (2015), 9 (9), 9167-9179CODEN: ANCAC3; ISSN:1936-0851. (American Chemical Society)
      Designing scaffolds that can mimic native skeletal muscle tissue and induce 3D cellular alignment and elongated myotube formation remains an ongoing challenge for skeletal muscle tissue engineering. Herein, we present a simple technique to generate core-shell composite scaffolds for mimicking native skeletal muscle structure, which comprise the aligned nanofiber yarn (NFY) core and the photocurable hydrogel shell. The aligned NFYs are prepd. by the hybrid compn. including poly(caprolactone), silk fibroin, and polyaniline via a developed dry-wet electrospinning method. A series of core-shell column and sheet composite scaffolds are ultimately obtained by encapsulating a piece and layers of aligned NFY cores within the hydrogel shell after photo-crosslinking. C2C12 myoblasts are seeded within the core-shell scaffolds, and the good biocompatibility of these scaffolds and their ability to induce 3D cellular alignment and elongation are successfully demonstrated. Furthermore, the 3D elongated myotube formation within core-shell scaffolds is also performed after long-term cultivation. These data suggest that these core-shell scaffolds combine the aligned NFY core that guides the myoblast alignment and differentiation and the hydrogel shell that provides a suitable 3D environment for nutrition exchange and mech. protection to perform a great practical application for skeletal muscle regeneration.
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    42. 42
      Zhang, Y.; Li, S.; Wen, X.; Tong, H.; Li, S.; Yan, Y. MYOC Promotes the Differentiation of C2C12 Cells by Regulation of the TGF-β Signaling Pathways via CAV1. Biology 2021, 10, 686,  DOI: 10.3390/biology10070686
      42
      MYOC Promotes the Differentiation of C2C12 Cells by Regulation of the TGF-β Signaling Pathways via CAV1
      Zhang, Yuhan; Li, Shuang; Wen, Xin; Tong, Huili; Li, Shufeng; Yan, Yunqin
      Biology (Basel, Switzerland) (2021), 10 (7), 686CODEN: BBSIBX; ISSN:2079-7737. (MDPI AG)
      Simple Summary: MYOC is a secreted glycoprotein and it expresses at high levels in skeletal muscle cells. However, the function of MYOC in muscle is still unclear. Accordingly, in this study, we examd. that MYOC expression increased gradually during C2C12 differentiation and it could promote the differentiation of C2C12. Furthermore, we demonstrated that MYOC could bind to CAV1. We further confirmed that CAV1 could pos. regulate C2C12 differentiation through the TGF-β pathway. At last, we detd. the relationship among MYOC, CAV1 and TGF-β. We found that MYOC promoted the differentiation of C2C12 cells by regulation of the TGF-β signaling pathways via CAV1. The present study is the first to demonstrate the mechanism of action of MYOC in C2C12 cells. It provides a novel method of exploring the mechanism of muscle differentiation and represents a potential novel method for the treatment of muscle diseases. Abstr.: Myocilin (MYOC) is a glycoprotein encoded by a gene assocd. with glaucoma pathol. In addn. to the eyes, it also expresses at high transcription levels in the heart and skeletal muscle. MYOC affects the formation of the murine gastrocnemius muscle and is assocd. with the differentiation of mouse osteoblasts, but its role in the differentiation of C2C12 cells has not yet been reported. Here, MYOC expression was found to increase gradually during the differentiation of C2C12 cells. Overexpression of MYOC resulted in enhanced differentiation of C2C12 cells while its inhibition caused reduced differentiation. Furthermore, immunopptn. indicated that MYOC binds to Caveolin-1 (CAV1), a protein that influences the TGF-β pathway. Laser confocal microscopy also revealed the common sites of action of the two during the differentiation of C2C12 cells. Addnl., CAV1 was upregulated significantly as C2C12 cells differentiated, with CAV1 able to influence the differentiation of the cells. Furthermore, the Western blotting anal. demonstrated that the expression of MYOC affected the TGF-β pathway. Finally, MYOC was overexpressed while CAV1 was inhibited. The results indicate that reduced CAV1 expression blocked the promotion of C2C12 cell differentiation by MYOC. In conclusion, the results demonstrated that MYOC regulates TGF-β by influencing CAV1 to promote the differentiation of C2C12 cells.
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    43. 43
      Nagai, Y.; Yokoi, H.; Kaihara, K.; Naruse, K. The mechanical stimulation of cells in 3D culture within a self-assembling peptide hydrogel. Biomaterials 2012, 33, 1044– 1051,  DOI: 10.1016/j.biomaterials.2011.10.049
      43
      The mechanical stimulation of cells in 3D culture within a self-assembling peptide hydrogel
      Nagai, Yusuke; Yokoi, Hidenori; Kaihara, Keiko; Naruse, Keiji
      Biomaterials (2012), 33 (4), 1044-1051CODEN: BIMADU; ISSN:0142-9612. (Elsevier Ltd.)
      The aim of this present study was to provide a scaffold as a tool for the investigation of the effect of mech. stimulation on three-dimensionally cultured cells. For this purpose, we developed an artificial self-assembling peptide (SPG-178) hydrogel scaffold. The structural properties of the SPG-178 peptide were confirmed by attenuated total reflection-Fourier transform IR spectroscopy (ATR-FTIR) and transmission electron microscopy (TEM). The mech. properties of the SPG-178 hydrogel were studied using rheol. measurements. The SPG-178 peptide was able to form a stable, transparent hydrogel in a neutral pH environment. In the SPG-178 hydrogel, mouse skeletal muscle cells proliferated successfully (increased by 12.4 ± 1.5 times during 8 days of incubation; mean ± SEM). When the scaffold was statically stretched, a rapid phosphorylation of ERK was obsd. (increased by 2.8 ± 0.2 times; mean ± SEM). These results demonstrated that the developed self-assembling peptide gel is non-cytotoxic and is a suitable tool for the investigation of the effect of mech. stimulation on three-dimensional cell culture.
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    44. 44
      Rauch, C.; Loughna, P. T. Stretch-induced activation of ERK in myocytes is p38 and calcineurin-dependent. Cell Biochem. Funct. 2008, 26, 866– 869,  DOI: 10.1002/cbf.1518
      There is no corresponding record for this reference.
    45. 45
      Aguilar-Agon, K. W.; Capel, A. J.; Martin, N. R. W.; Player, D. J.; Lewis, M. P. Mechanical loading stimulates hypertrophy in tissue-engineered skeletal muscle: Molecular and phenotypic responses. J. Cell. Physiol. 2019, 234, 23547– 23558,  DOI: 10.1002/jcp.28923
      There is no corresponding record for this reference.
    46. 46
      Heher, P.; Maleiner, B.; Prüller, J.; Teuschl, A. H.; Kollmitzer, J.; Monforte, X.; Wolbank, S.; Redl, H.; Rünzler, D.; Fuchs, C. A novel bioreactor for the generation of highly aligned 3D skeletal muscle-like constructs through orientation of fibrin via application of static strain. Acta Biomater. 2015, 24, 251– 265,  DOI: 10.1016/j.actbio.2015.06.033
      46
      A novel bioreactor for the generation of highly aligned 3D skeletal muscle-like constructs through orientation of fibrin via application of static strain
      Heher, Philipp; Maleiner, Babette; Prueller, Johanna; Teuschl, Andreas Herbert; Kollmitzer, Josef; Monforte, Xavier; Wolbank, Susanne; Redl, Heinz; Ruenzler, Dominik; Fuchs, Christiane
      Acta Biomaterialia (2015), 24 (), 251-265CODEN: ABCICB; ISSN:1742-7061. (Elsevier Ltd.)
      The generation of functional biomimetic skeletal muscle constructs is still one of the fundamental challenges in skeletal muscle tissue engineering. With the notion that structure strongly dictates functional capabilities, a myriad of cell types, scaffold materials and stimulation strategies have been combined. To further optimize muscle engineered constructs, we have developed a novel bioreactor system (MagneTissue) for rapid engineering of skeletal muscle-like constructs with the aim to resemble native muscle in terms of structure, gene expression profile and maturity. Myoblasts embedded in fibrin, a natural hydrogel that serves as extracellular matrix, are subjected to mech. stimulation via magnetic force transmission. We identify static mech. strain as a trigger for cellular alignment concomitant with the orientation of the scaffold into highly organized fibrin fibrils. This ultimately yields myotubes with a more mature phenotype in terms of sarcomeric patterning, diam. and length. On the mol. level, a faster progression of the myogenic gene expression program is evident as myogenic detn. markers MyoD and Myogenin as well as the Ca2+ dependent contractile structural marker TnnT1 are significantly upregulated when strain is applied. The major advantage of the MagneTissue bioreactor system is that the generated tension is not exclusively relying on the strain generated by the cells themselves in response to scaffold anchoring but its ability to subject the constructs to individually adjustable strain protocols. In future work, this will allow applying mech. stimulation with different strain regimes in the maturation process of tissue engineered constructs and elucidating the role of mechanotransduction in myogenesis. Mech. stimulation of tissue engineered skeletal muscle constructs is a promising approach to increase tissue functionality. We have developed a novel bioreactor-based 3D culture system, giving the user the possibility to apply different strain regimes like static, cyclic or ramp strain to myogenic precursor cells embedded in a fibrin scaffold. Application of static mech. strain leads to alignment of fibrin fibrils along the axis of strain and concomitantly to highly aligned myotube formation. Addnl., the pattern of myogenic gene expression follows the temporal progression obsd. in vivo with a more thorough induction of the myogenic program when static strain is applied. Ultimately, the strain protocol used in this study results in a higher degree of muscle maturity demonstrated by enhanced sarcomeric patterning and increased myotube diam. and length. The introduced bioreactor system enables new possibilities in muscle tissue engineering as longer cultivation periods and different strain applications will yield tissue engineered muscle-like constructs with improved characteristics in regard to functionality and biomimicry.
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    47. 47
      Li, Y.; Huang, G.; Gao, B.; Li, M.; Genin, G. M.; Lu, T. J.; Xu, F. Magnetically actuated cell-laden microscale hydrogels for probing strain-induced cell responses in three dimensions. NPG Asia Mater. 2016, 8, e238  DOI: 10.1038/am.2015.148
      47
      Magnetically actuated cell-laden microscale hydrogels for probing strain-induced cell responses in three dimensions
      Li, Yuhui; Huang, Guoyou; Gao, Bin; Li, Moxiao; Genin, Guy M.; Lu, Tian Jian; Xu, Feng
      NPG Asia Materials (2016), 8 (1), e238CODEN: NAMPCE; ISSN:1884-4057. (Nature Publishing Group)
      Living cells respond to their mech. microenvironments during development, healing, tissue remodeling and homeostasis attainment. However, this mechanosensitivity has not yet been established definitively for cells in three-dimensional (3D) culture environments, in part because of challenges assocd. with providing uniform and consistent 3D environments that can deliver a large range of physiol. and pathophysiol. strains to cells. Here, we report microscale magnetically actuated, cell-laden hydrogels (μMACs) for investigating the strain-induced cell response in 3D cultures. μMACs provide high-throughput arrays of defined 3D cellular microenvironments that undergo reversible, relatively homogeneous deformation following non-contact actuation under external magnetic fields. We present a technique that not only enables the application of these high strains (60%) to cells but also enables simplified microscopy of these specimens under tension. We apply the technique to reveal cellular strain-threshold and satn. behaviors that are substantially different from their 2D analogs, including spreading, proliferation, and differentiation. μMACs offer insights for mechanotransduction and may also provide a view of how cells respond to the extracellular matrix in a 3D manner.
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    48. 48
      Ahmed, W. W.; Wolfram, T.; Goldyn, A. M.; Bruellhoff, K.; Rioja, B. A.; Möller, M.; Spatz, J. P.; Saif, T. A.; Groll, J.; Kemkemer, R. Myoblast morphology and organization on biochemically micro-patterned hydrogel coatings under cyclic mechanical strain. Biomaterials 2010, 31, 250– 258,  DOI: 10.1016/j.biomaterials.2009.09.047
      There is no corresponding record for this reference.
    49. 49
      Okano, T.; Satoh, S.; Oka, T.; Matsuda, T. Tissue engineering of skeletal muscle. Highly dense, highly oriented hybrid muscular tissues biomimicking native tissues. ASAIO J. 1997, 43, M753,  DOI: 10.1097/00002480-199709000-00084
      There is no corresponding record for this reference.
    50. 50
      Ahadian, S.; Ramón-Azcón, J.; Chang, H.; Liang, X.; Kaji, H.; Shiku, H.; Nakajima, K.; Ramalingam, M.; Wu, H.; Matsue, T. Electrically regulated differentiation of skeletal muscle cells on ultrathin graphene-based films. RSC Adv. 2014, 4, 9534– 9541,  DOI: 10.1039/c3ra46218h
      50
      Electrically regulated differentiation of skeletal muscle cells on ultrathin graphene-based films
      Ahadian, Samad; Ramon-Azcon, Javier; Chang, Haixin; Liang, Xiaobin; Kaji, Hirokazu; Shiku, Hitoshi; Nakajima, Ken; Ramalingam, Murugan; Wu, Hongkai; Matsue, Tomokazu; Khademhosseini, Ali
      RSC Advances (2014), 4 (19), 9534-9541CODEN: RSCACL; ISSN:2046-2069. (Royal Society of Chemistry)
      The elec. cond. of graphene provides a unique opportunity to modify the behavior of elec. sensitive cells. Here, we demonstrate that C2C12 myoblasts that were cultured on ultrathin thermally reduced graphene (TR-Graphene) films had more favorable cell adhesion and spreading compared to those on graphene oxide (GO) and glass slide substrates, comparable with conventional Petri dish. More importantly, we demonstrate that elec. stimulation significantly enhanced myoblast cell differentiation on a TR-Graphene substrate compared to GO and glass slide surfaces as confirmed by the expression of myogenic genes and proteins. These results highlight the potential applications of graphene-based materials for cell-based studies, bioelectronics, and biorobotics.
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    51. 51
      Gao, J.; Sun, X.; Ma, Y.; Qin, W.; Li, J.; Jin, Z.; Qiu, J.; Zhang, H. Myotube formation on micropatterns guiding by centripetal cellular motility and crowding. Mater. Today Bio 2024, 28, 101195,  DOI: 10.1016/j.mtbio.2024.101195
      There is no corresponding record for this reference.
    52. 52
      Siegel, R.; Ma, J.; Zou, Z.; Jemal, A. Cancer statistics. Ca-Cancer J. Clin. 2014, 64, 9– 29,  DOI: 10.3322/caac.21208
      52
      Cancer statistics, 2014
      Siegel Rebecca; Ma Jiemin; Zou Zhaohui; Jemal Ahmedin
      CA: a cancer journal for clinicians (2014), 64 (1), 9-29 ISSN:.
      Each year, the American Cancer Society estimates the numbers of new cancer cases and deaths that will occur in the United States in the current year and compiles the most recent data on cancer incidence, mortality, and survival. Incidence data were collected by the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries and mortality data were collected by the National Center for Health Statistics. A total of 1,665,540 new cancer cases and 585,720 cancer deaths are projected to occur in the United States in 2014. During the most recent 5 years for which there are data (2006-2010), delay-adjusted cancer incidence rates declined slightly in men (by 0.6% per year) and were stable in women, while cancer death rates decreased by 1.8% per year in men and by 1.4% per year in women. The combined cancer death rate (deaths per 100,000 population) has been continuously declining for 2 decades, from a peak of 215.1 in 1991 to 171.8 in 2010. This 20% decline translates to the avoidance of approximately 1,340,400 cancer deaths (952,700 among men and 387,700 among women) during this time period. The magnitude of the decline in cancer death rates from 1991 to 2010 varies substantially by age, race, and sex, ranging from no decline among white women aged 80 years and older to a 55% decline among black men aged 40 years to 49 years. Notably, black men experienced the largest drop within every 10-year age group. Further progress can be accelerated by applying existing cancer control knowledge across all segments of the population.
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    53. 53
      Mueller, C.; Trujillo-Miranda, M.; Maier, M.; Heath, D. E.; O’Connor, A. J.; Salehi, S. Effects of External Stimulators on Engineered Skeletal Muscle Tissue Maturation. Adv. Mater. Interfaces 2021, 8, 2001167,  DOI: 10.1002/admi.202001167
      There is no corresponding record for this reference.
    54. 54
      Kim, W. J.; Jang, C. H.; Kim, G. H. A Myoblast-Laden Collagen Bioink with Fully Aligned Au Nanowires for Muscle-Tissue Regeneration. Nano Lett. 2019, 19, 8612– 8620,  DOI: 10.1021/acs.nanolett.9b03182
      There is no corresponding record for this reference.
    55. 55
      Herbst, A.; Aiken, J. M.; McKenzie, D. Replication of prions in differentiated muscle cells. Prion 2014, 8, 166– 168,  DOI: 10.4161/pri.27890
      There is no corresponding record for this reference.
    56. 56
      Smoak, M. M.; Hogan, K. J.; Grande-Allen, K. J.; Mikos, A. G. Bioinspired electrospun dECM scaffolds guide cell growth and control the formation of myotubes. Sci. Adv. 2021, 7, eabg4123  DOI: 10.1126/sciadv.abg4123
      There is no corresponding record for this reference.
    57. 57
      Campiglio, C. E.; Contessi Negrini, N.; Farè, S.; Draghi, L. Cross-linking strategies for electrospun gelatin scaffolds. Materials 2019, 12, 2476,  DOI: 10.3390/ma12152476
      57
      Cross-linking strategies for electrospun gelatin scaffolds
      Campiglio, Chiara Emma; Negrini, Nicola Contessi; Fare, Silvia; Draghi, Lorenza
      Materials (2019), 12 (15), 2476CODEN: MATEG9; ISSN:1996-1944. (MDPI AG)
      Electrospinning is an exceptional technol. to fabricate sub-micrometric fiber scaffolds for regenerative medicine applications and to mimic the morphol. and the chem. of the natural extracellular matrix (ECM). Although most synthetic and natural polymers can be electrospun, gelatin frequently represents a material of choice due to the presence of cell-interactive motifs, its wide availability, low cost, easy processability, and biodegradability. However, crosslinking is required to stabilize the structure of the electrospun matrixes and avoid gelatin dissoln. at body temp. Different phys. and chem. crosslinking protocols have been described to improve electrospun gelatin stability and to preserve the morphol. fibrous arrangement of the electrospun gelatin scaffolds. Here, we review the main current strategies. For each method, the crosslinking mechanism and its efficiency, the influence of electrospinning parameters, and the resulting fiber morphol. are considered. The main drawbacks as well as the open challenges are also discussed.
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    58. 58
      Demina, T. S.; Bolbasov, E. N.; Peshkova, M. A.; Efremov, Y. M.; Bikmulina, P. Y.; Birdibekova, A. V.; Popyrina, T. N.; Kosheleva, N. V.; Tverdokhlebov, S. I.; Timashev, P. S. Electrospinning vs. Electro-Assisted Solution Blow Spinning for Fabrication of Fibrous Scaffolds for Tissue Engineering. Polymers 2022, 14, 5254,  DOI: 10.3390/polym14235254
      There is no corresponding record for this reference.
    59. 59
      Shao, Y. H.; Huang, S. M.; Liu, S. M.; Chen, J. C.; Chen, W. C. Hybrid-Aligned Fibers of Electrospun Gelatin with Antibiotic and Polycaprolactone Composite Membranes as an In Vitro Drug Delivery System to Assess the Potential Repair Capacity of Damaged Cornea. Polymers 2024, 16, 448,  DOI: 10.3390/polym16040448
      There is no corresponding record for this reference.
    60. 60
      Rodríguez-Martín, M.; Aguilar, J. M.; Castro-Criado, D.; Romero, A. Characterization of Gelatin-Polycaprolactone Membranes by Electrospinning. Biomimetics 2024, 9, 70,  DOI: 10.3390/biomimetics9020070
      There is no corresponding record for this reference.
    61. 61
      Jang, Y.; Jang, J.; Kim, B. Y.; Song, Y. S.; Lee, D. Y. Effect of Gelatin Content on Degradation Behavior of PLLA/Gelatin Hybrid Membranes. Tissue Eng. Regener. Med. 2024, 21, 557– 569,  DOI: 10.1007/s13770-024-00626-4
      There is no corresponding record for this reference.
    62. 62
      Hotta, K.; Behnke, B. J.; Masamoto, K.; Shimotsu, R.; Onodera, N.; Yamaguchi, A.; Poole, D. C.; Kano, Y. Microvascular permeability of skeletal muscle after eccentric contraction-induced muscle injury: in vivo imaging using two-photon laser scanning microscopy. J. Appl. Physiol. 2018, 125, 369– 380,  DOI: 10.1152/japplphysiol.00046.2018
      There is no corresponding record for this reference.

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    • Response against electrostimulation of a mechanically stimulated scaffold (MP4)


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