Intelligent antibacterial surface with controllable sterilization and bacteria-releasing ability

Bacterial biofilm contamination has caused significant damage to the medical and food industries, and there is an urgent need to develop new antimicrobial coatings to address this problem. In this study, temperature-sensitive coatings with bacteria-killing and bacteria-releasing functions were prepared based on silicone rubber (SR) surfaces by ultraviolet (UV) polymerization and UV photocatalysis. Firstly, N-isopropylacrylamide (NIPAAm) was formed into poly(N-isopropylacrylamide) (PNIPAAm) by UV polymerization and grafted onto the SR surface. Then, Ag+ was rapidly reduced to silver nanoparticles (AgNPs) by tannic acid (TA) under UV catalysis to form TA@Ag complexes, depositing onto the SR surface. The modified SR surface has an extremely strong and persistent bactericidal effect, greatly inhibiting the formation of bacterial biofilm. Moreover, the smart surface can effectively release bacteria and resist bacterial adhesion through temperature changes. Moreover, the modified SR surface did not exhibit cytotoxicity against mouse epithelioid fibroblasts (L929). Taken together, the smart SR surface has antibacterial ability and good biocompatibility, which is a promising medical material.