Redox-Responsive Resilin-Like Hydrogels for Tissue Engineering and Drug Delivery Applications.

Resilin, a protein found in insect cuticles, is renowned for its outstanding elastomeric properties. The authors' laboratory previously developed a recombinant protein, which consisted of consensus resilin-like repeats from Anopheles gambiae, and demonstrated its potential in cartilage and vascular engineering. To broaden the versatility of the resilin-like protein, this study utilizes a cleavable crosslinker, which contains a disulfide bond, to develop smart resilin-like hydrogels that are redox-responsive. The hydrogels exhibit a porous structure and a stable storage modulus (G') of ≈3 kPa. NIH/3T3 fibroblasts cultured on hydrogels for 24 h have a high viability (>95%). In addition, the redox-responsive hydrogels show significant degradation in a reducing environment (10 mm glutathione (GSH)). The release profiles of fluorescently labeled dextrans encapsulated within the hydrogels are assessed in vitro. For dextran that is estimated to be larger than the mesh size of the gel, faster release is observed in the presence of reducing agents due to degradation of the hydrogel networks. These studies thus demonstrate the potential of using these smart hydrogels in a variety of applications ranging from scaffolds for tissue engineering to drug delivery systems that target the intracellular reductive environments of tumors.