Uniform zwitterionic polymer hydrogels with a nonfouling and functionalizable crosslinker using photopolymerization.

We reported previously the design and synthesis of a zwitterionic carboxybetaine dimethacrylate crosslinker, and we showed that its use with zwitterionic carboxybetaine methacrylate led to nonfouling hydrogels with high mechanical properties and high hydration. Now, we use photopolymerization to improve the uniformity of the polymer network, resulting in drastically improved mechanical properties (compressive modulus up to 90 MPa). Furthermore, we designed and synthesized a new functionalizable carboxybetaine dimethacrylate crosslinker, enabling functionalization of the higher strength hydrogels against a nonfouling background. Additionally, the biostability of the carboxybetaine hydrogel systems was tested, and it was found that these hydrogels are stable in oxidative, acidic, and basic environments.