Surface Modification of Poly(l-lactic acid) Membrane via Layer-by-Layer Assembly of Silver Nanoparticle-Embedded Polyelectrolyte Multilayer

The improvement of hydrophilicity, antibacterial activity, hemocompatibility, and cytocompatibility of poly(l-lactic acid) (PLLA) membrane was developed via polyelectrolyte multilayer (PEM) immobilization. Colloidal silver nanoparticles were prepared by using dextran sulfate (DS) as a stabilizer to precede chemical reduction by dextrose. The polysaccharide PEMs, including chitosan (CH) and dextran sulfate (DS)-stabilized silver nanosized colloid (DSS), were successfully deposited on the aminolyzed PLLA membrane in a layer-by-layer (LBL) self-assembly manner. The obtained results showed that the contact angle of PLLA membranes decreased with PEMs grafting layers and reached a steady value after four bilayers of coating, hence suggesting that full coverage was achieved. The PLLA−PEM membranes with DSS as the outermost layer could resist platelet adhesion and human plasma fibrinogen (HPF) adsorption, while prolonging the blood coagulation time. The PLLA−PEM membranes could possess antibacterial activity against Methicilin-resistant Staphylococus aureus (MRSA). In addition, the proliferation and viability of human endothelial cells (ECs) on PLLA−PEM membranes could be significantly improved. Overall results demonstrated that such a fast, easy processing and shape-independent method for an antithrombogenic coating can be used for applications in hemodialysis devices.