An Antibacterial Polypeptide Coating Prepared by In Situ Enzymatic Polymerization for Preventing Delayed Infection of Implants.

Delayed implant-associated infection is an important challenge, as the treatment involves a high risk of implant replacement. Mussel-inspired antimicrobial coatings can be applied to coat a variety of implants in a facile way, but the adhesive 3,4-dihydroxyphenylalanine (DOPA) group is prone to oxidation. Therefore, an antibacterial polypeptide copolymer poly(Phe 7 - stat -Lys 10 )- b -polyTyr 3 was designed to prepare the implant coating upon tyrosinase-induced enzymatic polymerization for preventing implant-associated infections. Both poly(Phe 7 - stat -Lys 10 ) and polyTyr 3 blocks have specific functions: the former provides intrinsic antibacterial activity with a low risk to induce antimicrobial resistance, and the latter is attachable to the surface of implants to rapidly generate an antibacterial coating by in situ injection of polypeptide copolymer since tyrosine could be oxidized to DOPA under catalyzation of skin tyrosinase. This polypeptide coating with excellent antibacterial effect and desirable biofilm inhibition activity is promising for broad applications in a multitude of biomedical materials to combat delayed infections.