Tackling microbial infection associated with biomaterial surfaces has been an urgent need. Synthetic β-peptide polymers can mimic host defense peptides and have potent antimicrobial activities without driving the bacteria to develop antimicrobial resistance. Herein, we demonstrate a plasma surface activation-based practical β-peptide polymer modification to prepare antimicrobial surfaces for biomedical materials such as thermoplastic polyurethane (TPU), polytetrafluoroethylene, polyvinyl pyrrolidone, polyvinyl chloride, and polydimethylsiloxane. The β-peptide polymer-modified surfaces demonstrated effective killing on drug-resistant Gram-positive and Gram-negative bacteria. The antibacterial function retained completely even after the β-peptide polymer-modified surfaces were stored at ambient temperature for at least 2 months. Moreover, the optimum β-peptide polymer (50:50 DM-Hex)-modified surfaces displayed no hemolysis and cytotoxicity. In vivo study using methicillin-resistant Staphylococcus aureus (MRSA)-pre-incubated TPU-50:50 DM-Hex surfaces for subcutaneous implantation revealed a 3.4-log reduction of MRSA cells after the implantation for 11 days at the surrounding tissue of implanted TPU sheet and significant suppression of infection, compared to bare TPU control. These results imply promising and practical applications of β-peptide polymer tethering to prepare infection-resistant surfaces for biomedical materials and devices.
Keywords: MRSA; antimicrobial surface; host defense peptide; subcutaneous infection; β-peptide polymer.