Silica mineralization on anisotropic gelatin-hydrogel scaffolds

We investigated the mechanisms of silica mineralization in the case where gelatin hydrogels provide a three-dimensional anisotropic template and scaffold. For isotropic hydrogels, silica formation was achieved only on the surface, but for anisotropic hydrogels it also occurred in the interior. Two stages of silica mineralization were identified: a reaction period at the beginning and a period when silica growth stops with the formation of a silica shell on the hydrogel surface. In addition, the silica-coated hydrogels exhibited increases in storage elastic modulus and sol-gel phase-transition temperature over pristine hydrogels. The results suggest that the inorganic shell inhibits the molecular motion of gelatin, and thus stabilizes the gelatin network.