Dual-functional antimicrobial coating based on the combination of zwitterionic and quaternary ammonium cation from rosin acid

Treatment of implant-associated infection is becoming more challenging, especially when bacterial biofilms form on the surface of implants. To address the challenge of biofilm infection, developing dual-functional antimicrobial coatings (antimicrobial and antifouling) to combat bacterial biofilm infection are superior to those based on a single modality due to avoiding the adverse effects arising from the latter. In this work, we reported an effective dual-functional coating based on the use of synthetic terpolymers, which combined dopamine, zwitterionic 2-methacryloyloxyethyl phosphorylcholine (MPC) and maleopimaric acid quaternary ammonium cation (MPA-N+). The modified surfaces were characterized by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), X-ray spectroscopy (XPS) and water contact angle measurements. The bactericidal efficacies of dual-functional coating were demonstrated by 1.00, 1.09 and 0.94 log reduction of Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, Pseudomonas aeruginosa, respectively, and effectively inhibited pathogenic biofilm formation. Moreover, the dual-function coating reduced protein and platelet absorption, while showing minimal cytotoxicity to the mammalian cells. Notably, an in vivo implantation model showed that the dual-functional coating eradicated the pathogenic biofilm from the implants, preventing host tissue damage and inflammation. Taken together, this dual-functional coating displayed great therapeutic potential in treating the formidable clinic problems caused by pathogenic biofilm and the accompanying inflammation.

Automated summary

A dual-functional coating based on synthetic terpolymers was developed to combat implant-associated infection caused by bacterial biofilm formation. The coating exhibited strong bactericidal efficacy against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, and effectively inhibited biofilm formation. In addition, the coating showed reduced protein and platelet absorption and minimal cytotoxicity to mammalian cells. In vivo experiments demonstrated that the coating eradicated pathogenic biofilm, preventing tissue damage and inflammation.