Enzyme-catalyzed crosslinking in a partly frozen state: a new way to produce supermacroporous protein structures

In this study a new way to produce supermacroporous protein structures was investigated. Enzyme-mediated crosslinking of gelatin or casein was performed in a partly frozen state, which yielded stable, protein-based cryogels. The reaction kinetics for the formation of cryogels were found to be fairly slow, most likely due to the low temperature (-12 °C) used or due to an increased viscosity owing to the cryo-concentration taking place. The produced cryogels were characterized with regards to their physical properties and in vitro degradation. Furthermore, cryogels produced from gelatin and casein were evaluated as potential scaffolds by fibroblast cultivation to confirm their in vitro biocompatibility. Gelatin- and casein-based scaffolds both supported cell proliferation and migration through the scaffold.