Keratin-based hydrogels and aqueous compositions and methods for forming the hydrogels and compositions are described. The compositions include solubilized keratin that has been functionalized to include a crosslinking moiety. The crosslinking moiety exhibits controllable crosslinking, e.g., a photopolymerizable crosslinking moiety. The crosslinking functionality is bonded to the keratin via cysteines following reduction of disulfide bonds of the native keratin. The compositions can be injectable and can include living cells and/or other biologically active agents, for instance for use in tissue regeneration.
