Antifouling and Bactericidal Zwitterionic Polymer Coatings with Synergistic Inhibitory and Killing Properties

Polymeric coatings that combine resistance to adhesion ("defending") and killing ("attacking") of biocontaminants were proposed to endow the surface with nonadhesive and bactericidal capabilities. In contrast, a zwitterionic copolymer P(GMA-co-DMAPS) with antifouling groups ([2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide, DMAPS) and a zwitterionic/cationic copolymer P(GMA-co-DMAPS-co-DMC) with bactericidal groups ([2-(methacryloyloxy)ethyl]trimethylammonium chloride, DMC) were synthesized, of which the latter exhibited synergistic inhibitory and killing properties. The distinct feed ratios of monomers were conducted, and the optimal molar ratio was obtained. The polymer coating was chemically bonded to the surface of substrates such as stainless steel via the addition-elimination reaction of epoxy groups and hydroxyl groups. Stainless steel surfaces grafted with G20D80-5DMC exhibited fine antifouling and bactericidal properties. The results showed that a highly efficient defending-attacking synergistic effect was achieved with antiprotein adsorption of more than 90% and bactericidal rates against Staphylococcus aureus and Escherichia coli of 98.6% and 96.6%, respectively. The polymers proposed in this study can effectively play an antifouling and antibacterial synergistic role and can be grafted onto substrates through a simple and effective method, showing attractive potential in marine, biomedical, and industrial applications.