Ag-nanogel blended polymeric membranes with antifouling, hemocompatible and bactericidal capabilities

Abstract

A highly efficient, universal and convenient protocol is reported to fabricate antifouling, hemocompatible, and bactericidal membranes by physically blending antifouling nanogels and in situ silver nanoparticle immobilization. Firstly, nanogels are synthesized by one-step cross-linking co-polymerization of an antifouling monomer, poly(ethylene glycol) methacrylate (PEGMA), and an anchoring monomer, methylacrylic acid (MAA). Then, the nanogels are physically blended with a membrane matrix to generate nanogel embedded composite membranes. Finally, the in situ growth of silver nanoparticles in the composite membranes is successfully achieved by electrostatic adsorption of Ag⁺ ions and vitamin C reduction. The successful preparation of Ag-nanogel blended polymeric membranes has been confirmed by FTIR spectra and XPS patterns. The surface SEM images suggest that there are abundant Ag-nanogels embedded on the composite membrane surfaces. The cross-sectional SEM images give clear evidence that the Ag-nanogel immobilized composite membranes have well-maintained finger-like structure with increased porosity; meanwhile, the uniform distribution of the Ag-nanogels in the membrane matrix is confirmed by elemental EDX mapping. The systematic tests of water contact angle, static protein adsorption and ultrafiltration experiments indicate that the hydrophilicity, water flux, and antifouling properties of the composite membranes are substantially improved. More importantly, prolonged blood clotting time and suppressed platelet adhesion/activation indicate that the composite membranes have better blood compatibility and ultralow thrombotic potential. Bactericidal studies reveal that the modified membranes exhibit remarkable inhibition and killing capability toward both S. aureus and E. coli bacteria. The results reveal that robust antifouling, hemocompatible, and bactericidal composite membranes have been prepared via the proposed blending of nanogels and loading of Ag nanoparticles. This approach is believed to have great potential for fabricating various multifunctional membranes for industrial and clinical usage.