Biofabricating a Silk Scaffold as a Functional Microbial Trap

Silk fibroin produced from silkworms has been intensively utilized as a scaffold material for a variety of biotechnological applications owing to its remarkable mechanical strength, extensibility, biocompatibility, and ease of biofunctionalization. In this research, we engineered silk as a novel trap platform capable of capturing microorganisms. Specifically, we first fabricated the silk material into a silk sponge by lyophilization, yielding a 3D scaffold with porous microstructures. The sponge stability in water was significantly improved by ethanol treatment with elevated beta-sheet content and crystallinity of silk. Next, we biofunctionalized the silk sponge with a poly-specific microbial targeting molecule, ApoH (apolipoprotein H), to enable a novel silk-based microbial trap. The recombinant ApoH engineered with an additional penta-tyrosine was assembled onto the silk sponge through the horseradish peroxidase (HRP) mediated dityrosine cross-linking. Last, the ApoH-decorated silk sponge was demonstrated to be functional in capturing our model microorganism targets, E. coli and norovirus-like particles. We envision that this biofabricated silk platform, capable of trapping a variety of microbial entities, could serve as a versatile scaffold for rapid isolation and enrichment of microbial samples toward future diagnostics and therapeutics. This strategy, in turn, can expedite advancing future biodevices with functionality and sustainability.