Silk-based nano-hydrogels for futuristic biomedical applications

Silk proteins have attracted much scientific attention due to their potential to design novel biomaterials for biomedical applications, including drug delivery systems, tissue engineering, wound healing, biosensors, and other electronic devices. Different silk-based hydrogels and nanogels have been designed to have high efficiency in overcoming the limitation of conventional polymers. Efforts have been devoted to precisely fabricating the silk gels to improve biodegradability, processability, biocompatibility, selective designing, and cell-encapsulation possibilities that make silk an attractive candidate for biomedical settings. In addition, the more specialized gels are being designed for accurate targeting of required applications. This review aims to provide in-depth knowledge in silk-based hydrogels and nanogels development with biomedical potentialities, including drug/gene delivery, tissue engineering, and wound healing applications. Various studies have been summarized explaining the specific functionalization of silk to incorporate novel features in the gels are also discussed. The review ends with potential challenges and prospects in developing silk-based "smart" material with desired functionalities.