(113b) Zwitterionic Hydrogel Coatings Photografted to Biomaterial Surfaces Decrease Fibrotic Response and Increase Lubricity

Zwitterionic hydrogels have shown promise in reducing biofouling in many biological environments. By using photopolymerization to simultaneously initiate polymerization of a bulk hydrogel and photograft to the desired surface, robust zwitterionic coatings are created on various biomaterials. This work examines antifouling properties and lubricity resulting from these coating systems. The binding of water by zwitterionic moieties reduces attachment of proteins and cells, thus leading to a decrease in biofouling. Two zwitterionic monomers have been examined: sulfobetaine methacrylate (SBMA) and carboxybetaine methacrylate (CBMA). Because CBMA binds water molecules more effectively, CBMA hydrogels typically are more effective in preventing biofouling. Crosslinker is used to create the bulk hydrogel, imparting greater mechanical durability but diminishing antifouling effectiveness, especially at higher percents. Lubricity is greatly increased by the zwitterionic hydrogel coatings for a variety of surfaces, including various biological tissues. The force needed during implantation of coated cochlear implants is significantly decreased, likely as a result of the improved lubricity. Less force should result in less trauma, thereby likely leading to lower fibrotic response to implants.