Robust Silk Protein Hydrogels Made by a Facile One-Step Method and Their Multiple Applications

Silk fibroin is a natural polymer that has various material forms and wide applications. Hydrogel is one of the most attractive silk materials because of its hydrophilicity, biocompatibility, and flexibility. However, its applications are still quite limited because they have a complicated preparation process and/or low mechanical strength. Herein, a simple way to prepare tough silk fibroin hydrogels via a solvent-exchange method is introduced. The degummed silk fiber was directly dissolved in a calcium chloride/formic acid solution and then water was used to replace the solvent. The silk fibroin hydrogel that was obtained using this facile method exhibited even better mechanical properties than most silk fibroin hydrogels that have been reported in the literature. Also, the silk fibroin hydrogel maintained biocompatibility that was as good as that prepared via other methods. Finally, the possibility of using this regenerated silk fibroin hydrogel as a multi-functional platform (such as a catalyst carrier, photothermal agent, and underwater adhesive) has been discussed. Therefore, such a natural, sustainable, robust, and good biocompatible silk fibroin hydrogel that is prepared by an improved method may have great potential for further applications.