High-Performance Smart Hydrogels with Redox-Responsive Properties Inspired by Scallop Byssus.

Smart hydrogels with versatile properties, including a tunable gelation time, nonswelling attributes, and biocompatibility, are in great need in the biomedical field. To meet this urgent demand, we explored novel biomaterials with the desired properties from sessile marine organisms. To this end, a novel protein, Sbp9, derived from scallop byssus was extensively investigated, which features typical epidermal growth factor-like (EGFL) multiple repetitive motifs. Our current work demonstrated that the key fragment of Sbp9 (calcium-binding domain (CBD) and 4 EGFL repeats (CE4)) was able to form a smart hydrogel driven by noncovalent interactions and facilitated by disulfide bonds. More importantly, this smart hydrogel demonstrates several desirable and beneficial features, which could offset the drawbacks of typical protein-based hydrogels, including (1) a redox-responsive gelation time (from <1 to 60 min); (2) tunable mechanical properties, nonswelling abilities, and an appropriate microstructure; and (3) good biocompatibility and degradability. Furthermore, proof-of-concept demonstrations showed that the newly discovered hydrogel could be used for anticancer drug delivery and cell encapsulation. Taken together, a smart hydrogel inspired by marine sessile organisms with desirable properties was generated and characterized and demonstrated to have extensive applicability potential in biomedical applications, including tissue engineering and drug release.