(182v) Thermoresponsive Protein Hydrogels for Sustained Delivery of Small Molecules

Protein-based hydrogels are increasingly being used for therapeutics delivery due to their biodegradability, bioavailability, and biocompatibility relative to their synthetic polymer-based counterparts. In particular thermoresponsive hydrogels, which undergo gelation in response to a change in temperature, have fast been gaining traction. Although lower critical solution temperature (LCST) gels, which gel above a certain temperature, have been extensively characterized for their structural and mechanical properties and their applicability in therapeutics delivery, upper critical solution temperature (UCST) gels have not been widely studied. Herein, we present a hydrogel that exhibits UCST phase behavior, forming a gel below the transition temperature of the protein. The hydrogel described is based on a single coiled-coil protein, Q, which is an engineered variant of the coiled-coil domain of cartilage oligomeric matrix protein (COMPcc). Using transmission electron microscopy, Q has been shown to assemble into nanofibers, which then physically cross-link at low temperature to form a hydrogel. Upon binding with the small hydrophobic molecule, curcumin, the Q hydrogel showed enhanced mechanical properties and thermostability, while showing a sustained release profile over time, thus demonstrating its possible efficacy as a vehicle for the delivery of small hydrophobic molecules.