Silk fibroin hydrogels: Gelation mechanisms, fabrication techniques, and biomedical applications

Regenerated silk fibroin (RSF) hydrogels have attracted significant interest for biomedical applications, such as tissue engineering, drug delivery, and smart devices, due to their biocompatibility, biodegradability, and customizable mechanical properties. This review elaborates the gelation mechanisms and fabrication methods for RSF hydrogels, covering both the chemical and physical approaches. We also detail the commonly used techniques in assessing the primary characteristics of RSF hydrogel, including the secondary structures, gelation kinetics, microstructures, and mechanical properties. Furthermore, the development of RSF hydrogels in advanced biomedical and intelligent device applications are explored in detail. Ultimately, despite the promising advantages, several challenges persist, and we discuss the future directions to address these issues and unlock the full potential of RSF hydrogel.