Biodegradable Polymer with Hydrolysis-Induced Zwitterions for Antibiofouling

Persistent protein resistance is critical for marine antibiofouling. We have prepared copolymer of 2-methylene-1,3-dioxepane (MDO), tertiary carboxybetaine ester (TCB), and 7-methacryloyloxy-4-methylcoumarin (MAMC) via radical ring-opening polymerization, where MDO, TCB, and MAMC make the polymer degradable, protein resistible, and photo-cross-linkable, respectively. Our study shows that the polymer can well adhere to the substrate with controlled degradation and water adsorption rate in artificial seawater (ASW). Particularly, the polymer film can generate zwitterions via surface hydrolysis in ASW. Quartz crystal microbalance with dissipation measurements reveal that such hydrolysis-induced zwitterionic surface can effectively resist nonspecific protein adsorption. Moreover, the surface can inhibit the adhesion of marine bacteria Pseudomonas sp. and Vibrio alginolyticus as well as clinical bacterium Escherichia coli.