Inhibition of Bacterial Adhesion on Hydroxyapatite Model Teeth by Surface Modification with PEGMA-Phosmer Copolymers

Modification of the interface properties on hydroxyapatite and tooth enamel surfaces was investigated to fabricate bacterial resistance in situ . A series of copolymers containing pendants of poly(ethylene glycol) methyl ether methacrylate (PEGMA) and ethylene glycol methacrylate phosphate (Phosmer) were polymerized by conventional free radical polymerization and changing the feed ratio of monomers. The copolymers were immobilized on hydroxyapatite and tooth enamel via the affinity of phosphate groups to hydroxyapatite to form the stable and durable polymer brushes on the surfaces. The amounts of polymer immobilized depended on the phosphate group ratio in the copolymers. Surface modification altered the interfacial properties of hydroxyapatite and inhibited bacterial adhesion. Copolymers containing 40–60% PEGMA segments showed a significant inhibitory effect on bacterial adhesion of S. epidermidis both in the presence and absence of plaque model biomacromolecules.