Polyzwitterions have great potential as fouling-resistant materials for biomedical and environmental products, in particular, in the form of hydrogel coatings. While typically these are soft materials, for many applications it is also necessary to achieve sufficient mechanical stability. This may be accomplished by high degrees of cross-linking, which, however, will impair the overall hydrophilicity of the gels for the commonly used hydrophobic cross-linkers. To mitigate this dilemma, a zwitterionic methacrylate monomer was developed that contains a benzophenone moiety as a photo-cross-linkable unit and a hydrophilic zwitterionic sulfobetaine moiety. Copolymers of the standard sulfobetaine methacrylate 3-[