(696h) A Simple One-Step Deposition of Zwitterionic Polymer for Providing Biomaterials’ Antifouling Ability Via Aminomalononitrile Polymerization

Non-fouling biomaterials surfaces that resist protein adsorption and cell adhesion are highly desirable for many biomedical applications such as blood-contacting devices and biosensors. A common feature for non-fouling materials is the ability to bind water molecules tightly. In comparison with a widely used anti-fouling polymer, poly(ethylene glycol), that achieves hydration via hydrogen bonding, zwitterionic materials, such as phosphobetaine, sulfobetaine and carboxybetaine, bind water molecules more strongly via electrostatically induced hydration. Decoration of biomaterials surfaces with zwitterionic polymers has shown to greatly reduce non-specific protein adsorption and cell adhesion. Techniques for surface conjugation of zwitterionic molecules are in great demand.

The surface-immobilization strategies can be categorized into ‘‘graft-to’’ and ‘‘graft-from’’ methods. Nevertheless, most of the methods could be only applied to specific types of substrates. A universal surface modification method is needed for the anti-fouling applications of zwitterionic polymers. In this study, we applied a facile and universal surface modification method based on prebiotic chemistry. The hydrogen cyanide trimer, aminomalononitrile (AMN) could polymerize to give a brown complex nitrogenous polymer on a wide variety of substrates. A copolymer of sulfobetaine methacrylate and 2-aminoethylmethacrylate (poly(SBMA-co-AEMA)) was synthesized, and then immobilized on biomaterials along with the deposition of polyAMN. The immobilization of poly(SBMA-co-AEMA) was demonstrated via the examination of X-ray photoelectron spectroscopy, water contact angle measurement, and atomic force microscope. We found that the zwitterionic polymer could be conjugated on biomaterials and display its anti-fouling capacity. Cell adhesion and protein adsorption were greatly reduced on the poly(SBMA-co-AEMA)-modified substrates. In conclusion, the one-step modification method provides a facile and effective approach to construct antifouling surfaces.