Self-Assembled Antimicrobial and Biocompatible Copolymer Films on Titanium

Abstract

Copolymers of 4-vinyl-N-hexylpyridinium bromide and dimethyl(2-methacryloyloxyethyl) phosphonate self-assemble to form ultrathin layers on titanium surfaces that show antimicrobial activity, and biocompatibility. The copolymer layers are characterized by contact angle measurements, ellipsometry and XPS. Antibacterial activity is assessed by investigation of adherence of S. mutans. Biocompatibility is rated based on human gingival fibroblast adhesion and proliferation. By balancing the opposing effects of the chemical composition on biocompatibility and antimicrobial activity, copolymer coatings are fabricated that are able to inhibit the growth of S. mutans on the surface but still show attachment of gingival fibroblasts, and therefore might prevent biofilm formation on implants. A series of copolymers is designed containing membrane-disrupting quaternary ammonium groups as antimicrobial agents and phosphonate groups for surface activity. One distinct polymer composition is identified that is suitable for dental implant coatings as it shows a significant reduction in adhesion of S. mutans and at the same time sufficient biocompatibility towards human gingival fibroblasts. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.