Silk fibroin nanomaterials

Silk fibroin (SF) is the US Food and Drug Administration (FDA) approved natural polymer biomaterial with properties of high biocompatibility, biodegradability, and processability. Recently, many studies used SF as biomaterials for drug delivery and tissue engineering. Due to the high surface to volume ratio, nanomaterials are considered good candidates for the next generation in the field of medicine. In the current chapter, we will focus on SF nanomaterials and their application in biomaterials. In brief, the different types of silk cocoons as well as the general manufacturing protocols of SF, mainly including steps of degumming, dissolving, and purification were introduced. Moreover, the physicochemical properties of SF, especially SF secondary structure, biocompatibility, controllable degradation behavior, and ability of encapsulating drugs, have been summarized. Then, the subtypes of SF-based nanomaterials will be summarized, including nanoparticles (NPs), nanofibers, nanoshells, and nanogels. The medical applications of SF nanomaterials will be also outlined in term of drugs delivery and tissue engineering. The drawbacks of SF nanomaterials in field of medical application will be also discussed. For example, the colloidal stability of SF NPs as drug delivery carriers should be improved. Besides, the biological toxicity of SF nanomaterials will be also included in this chapter. For example, SF nanomaterials have been shown to involve in nuclear factor (NF)-κB signaling pathway. Finally, SF composite materials have been developed to improve the property defects of SF. In summary, SF-based nanomaterials are promising candidates in biological applications.