Popis: |
Hydrogels are an attractive class of materials that possess similar structural and functional characteristics to biological tissues, and demonstrate a diversity of applications in biomedical engineering. Silk fibroin (SF) is a unique natural polymer for its versatile formats, excellent processability, biocompatibility, tunable biodegradation and thus a good hydrogel candidate for bio-applications. Compared to synthetic polymer hydrogels, poor mechanical performance is still a fatal drawback that hinders the application of SF hydrogels. Researchers have attempted to develop strategies to construct silk fibroin-based high strength hydrogels (SF-HSHs). Herein, we review the processing approaches to prepare SF-HSHs with a focus on the gelation mechanisms. The mechanical properties of SF-HSHs are summarized under four categories according to the gelation mechanism, physical-crosslinked, dual-crosslinked, double network and composites. Furthermore, a brief description of the utility of SF-HSHs in biomedicine and devices is presented. Finally, the potential challenges and future development of SF-HSHs are briefly discussed. This review will enhance our understanding on the structure-property-function relationships of soft materials from natural polymers, and guide future biomedical applications of silk fibroin-based hydrogels. |