Molecular Mechanism of Rabbit Hair Keratin Hydrogel Fabricated via Cryoablation

Abstract

AbstractKeratins are highly attractive natural biomaterials for medical applications due to their inherent self‐assembly characteristics and biocompatibility. In this study, the molecular mechanism of rabbit hair keratin (RHK) gelation during cryogelation is investigated and the influence of cryogelation parameters on the gelation of keratin is systematically evaluated. Re‐xidation of free cysteine thiols and formation of hydrogen bond are determined to be the main stabilizing forces in self‐assembly of RHK gel, and ionic bonds are found to affect the uniformity of keratin hydrogels. pH affects the gelation by changing the electrostatic interaction between keratin molecules. Keratin will accumulate when pH is too low, but the stability of keratin hydrogels becomes worse when the pH is too high. With successive freezing–thawing (FT) cycles, the storage modulus of RHK cryogels substantially improved from 240.66 Pa at FT cycle 3 to 2483.3 Pa at FT cycle 9. Maintaining the balance of the interactive force between keratin molecules and between keratin molecules and water molecules is the basis of preparing uniform and stable keratin hydrogels.