Bacterial Adhesion on Honeycomb-Structured Poly(L-Lactic Acid) Surface with Ag Nanoparticles

Polymeric materials with ordered porous structure have received increasing interest due to their potential applications in biomaterials. However, the enhancement of cell proliferation by this porous structure also raises worries about the increase of bacterial adhesion. For their further use as biomaterials in vivo, it is essential to assess the bacterial adhesion on porous polymer films and find strategies to inhibit the bacterial retention. Honeycomb-structured poly(L-lactic acid) (PLLA) films with Ag nanoparticles were used in this purpose. The Ag⁺ release rate of Ag/PLLA films was analyzed. In vitro bacterial adhesions of S. aureus and E. coli on flat PLLA films, flat Ag/PLLA films, and honeycomb-structured Ag/PLLA films were compared. Ag nanoparticles activity appears to be more effective against bacteria in honeycomb-structured films compared with flat films of the same material. This activity is particularly significant when E. coli is used. The results suggest that the honeycomb surface topography, as well as the enhanced release of Ag⁺, can greatly contribute to the anti-adhesion property of PLLA surface. These honeycomb-structured Ag/PLLA films also have no significant cytotoxicity. The decoration of Ag nanoparticles in honeycomb structure provides an effective and safe strategy to reduce the bacterial adhesion on porous polymer surface.