Mussel-Inspired, Surface-Attachable Initiator for Grafting of Antimicrobial and Antifouling Hydrogels

In this work, a novel biomimetic surface-attachable initiator is successfully synthesized by the conjugation of 3,4-dihydroxyphenylacetic acid and thermal 2,2'-azobis(2-methylpropionamide) dihydrochloride (V-50). The synthesized initiator (DOPV) can adhere to various material surfaces in a mussel-inspired way and initiate the surface grafting polymerization. Hydrogel coatings are facilely prepared by the thermal-initiated radical copolymerization of antimicrobial polyhexamethylene guanidine and antifouling polyethylene glycol oligomers. The developed hydrogel coatings not only show antimicrobial activity toward gram-negative and gram-positive bacteria but also demonstrate protein resistance, antibiofilm efficacy, hemocompatibility, and low cytotoxicity in vitro. Most importantly, the hydrogel coatings reveal excellent antimicrobial efficacy with a log reduction above 5 in a rodent subcutaneous infection model. These results demonstrate the potential fabrication of bio-functional coatings for biomedical devices or implants through an inexpensive, facile, and environmentally friendly mussel-inspired technique.