Examining the Fouling Resistance of Random Zwitterionic Amphiphilic Copolymers

Nanoscale amphiphilic surfaces combine both the benefits of hydrophobic self-cleaning materials and the enthalpic barrier that comes from hydrophilic surfaces. Amphiphilic block or hyperbranched copolymers that self-assemble into domains of 10-100 nm can prevent the adhesion of some marine microorganisms. However, these systems often do not entirely resist the adsorption of biomacromolecules such as proteins. Random zwitterionic amphiphilic copolymers (r-ZACs) have much smaller domain sizes and may be an effective alternative to these materials. Our group has shown that r-ZACs have the ability to self-assemble into domains of <1-2 nm and exhibit unmatched fouling resistance as membrane-selective layers. However, no intensive material studies have been performed on r-ZACs as coatings. To address this unmet need, we have synthesized a cohort of r-ZACs at varying compositions and chemical structures and analyzed their water uptake, tensile properties, water contact angle, and thermal properties. We examined their protein fouling resistance through quartz crystal microbalance with dissipation (QCM-D) monitoring of the coatings while in contact with various protein solutions and through measuring the adsorption of GFP-producing E.coli cells. Increasing the understanding of the link between non-specific protein adsorption and biofouling of random zwitterionic amphiphilic copolymers (r-ZACs) and their chemical structure and composition will allow for the development of the next generation of fouling-resistant copolymers.