A sol-gel based silver nanoparticle/polytetrafluorethylene (AgNP/PTFE) coating with enhanced antibacterial and anti-corrosive properties

In this research, a silver nanoparticle/polytetrafluorethylene (AgNP/PTFE) coating for metallic implants was fabricated using a facile layer-by-layer coating method. PTFE nanoparticles were immobilized in a sol-gel matrix and dip-coated onto 316L stainless steel via a mussel-inspired approach followed by AgNP deposition. Benefiting from the synergistic effect of antibacterial AgNP and non-stick PTFE, the AgNP/PTFE coating exhibited superior antibiofilm activity against Escherichia coli WT F1693 and enhanced corrosion resistance. Compared with surfaces only coated with PTFE, the AgNP/PTFE coated surfaces were capable of sustained release of silver ions, inhibiting up to ∼50% bacterial biomass accumulation after 7 days. To understand the anti-adhesion mechanism, both classic DLVO and XDLVO theories were used to model and explain bacterial adhesion. Despite concerns that an over-release of silver ions may cause toxic effects towards mammalian cells, the coating procedures offered ease of control over the silver loading, making it potentially useful for preventing metallic implant-associated infections.