Anionic Surfactant-Facilitated Coating of Antimicrobial Peptide and Antibiotic Reduces Biomaterial-Associated Infection

Medical devices are widely used in modern medicine, but the high prevalence of biomaterial-associated infections still presents a major problem. Especially problematic is the formation of biofilms that are tolerant to most antibiotics. In this report, antimicrobial peptides (AMPs) were driven into an amphipathic structure by anionic surfactant. To increase the coating efficacy and spectrum of antimicrobial activity, the AMPs were coated simultaneously with antibiotic, Polymyxin B, by surfactant onto polystyrene, silicone, polyurethane, and titanium which are commonly used with biomedical devices. These coated antimicrobials stably adhered to the substrate and were gradually released into urine and serum. They exhibited high bactericidal activity, but low cytotoxicity and hemolytic activity. Most importantly, the antimicrobials coated onto silicone tubing inhibited the planktonic growth of <i>E. coli</i> in mouse urine and also markedly prevented bacterial adherence to the bladder and the silicone tubing implanted in the bladder. These results provide a promising approach to circumvent catheter-associated infections due to bacterial adherence.