Polyurethane surface modified with a hydrophilic polymer containing quaternary ammonium bromide

Surface with antibacterial function is important in inhibiting bacteria or biofilm formation on biomedical materials. This study reports synthesis of a quaternary ammonium bromide and N-vinylpyrrolidone-constructed antibacterial copolymer, coating it onto polyurethane surface, and evaluation of the coated surface. Antibacterial activity, surface contact angle, and protein adsorption of the coated surface were evaluated. With N-vinylpyrrolidone and quaternary ammonium bromide incorporation, the coated surface showed significantly increased hydrophilicity by exhibiting a 7 to 49% decrease in contact angle, enhanced antibacterial properties by exhibiting a 16 to 60% decrease in bacterial viability, reduced protein adsorption by demonstrating a 4 to 44% decrease in human serum albumin adsorption, and reduced bacterial adhesion by showing a 32–68% decrease in bacterial adhesion, as compared to unmodified polyurethane, as compared to unmodified polyurethane. The result indicates that the longer the substitute chain on the quaternary ammonium bromide, the higher the contact angle, the stronger the antibacterial activity, and the higher the protein adsorption as well as bacterial adhesion that the modified polyurethane surface exhibits.