Surface-engineered nanogel assemblies with integrated blood compatibility, cell proliferation and antibacterial property: towards multifunctional biomedical membranes

In this study, novel 3D multifunctional nanolayers are fabricated on biomedical membrane surfaces via layer-by-layer (LBL) self-assembly of nanogels and heparin-like polymers. To integrate long-term antibacterial activity, Ag nanoparticles embedded in nanogels were first prepared. Then, the Ag nanogels were assembled onto membrane surfaces by electrostatic interaction. To obtain a heparin-mimicking surface, the as-prepared nanogel-coated membranes were further assembled with heparin-like polymers by two different processes. The results indicated that the obtained nanogel and heparin-mimicking polymer assembled membranes exhibited 3D surface morphologies. Systematical blood compatibility and antithrombotic evaluations revealed that the functionalized membranes showed increased hydrophilicity, decreased protein adsorption, and prolonged clotting times and greatly suppressed platelet adhesion compared to pristine membrane. The cell culture observations demonstrated that the pristine, nanogel-assembled, and heparin-mimicking membranes showed different performances in terms of endothelial cell proliferation and adhesion morphology. The results of the antibacterial study indicated that the functionalized membranes exhibited significant inhibition capability for Escherichia coli and Staphylococcus aureus. In general, the surface coassembly of nanogels and heparin-mimicking polymers produced functionalized membranes with integrated blood compatibility, cell proliferation and antibacterial properties for multiple applications, which may advance the fabrication of biomedical devices by surface assembly of functional nanogels.