An Efficient Biosynthetic System for Developing Functional Silk Fibroin-Based Biomaterials

Long historical evolution and domestication endow silkworms with the super ability to synthesize and secrete massive silk proteins using silk glands. The major component of this secretion consists of silk fibroin, considered a promising biomaterial for tissue repairs and engineering. To further expand the utility of this unique protein, there is a continuing need for silk fibroin functionalization. Here, a highly-efficient Fib-H^EXP biosynthetic system is established to synthesize massive recombinant RFP in silk fibers using transgenic silkworms, which accounts for ≈7.86% of silk mass and achieves fabrication of fluorescent silk fibroin (SF) biomaterials. The universality of the Fib-H^EXP system is validated by genetic engineering glucose oxidase (GOx) functionalized silk fibers for fabricating GOx-SF hydrogels with antimicrobial activity to promote healing of infected diabetic wounds in mouse through the enzyme-catalyzed reaction of glucose to gluconic acid and H₂O₂. These findings demonstrate that the Fib-H^EXP system provides an opportunity for genetic functionalization of SF to broaden the utility of this biomaterial for a range of potential applications.