Expanded Tunability of Dynamic Hydrogel Stiffness Using Engineered Photoresponsive Proteins

Abstract

The extracellular matrix (ECM) plays an important role in regulating cell fate and function through dynamic and heterogenous presentation of well-defined chemical and mechanical cues. Though several research efforts have been fo- cused on trying to elucidate the effects of ECM-mediated cues on cell function, few in vitro platforms have been able to capture the four-dimensionality of me- chanical signaling that is presented in vivo. Towards this, our group recently introduced a hydrogel platform that undergoes reversible stiffening, made pos- sible using a fusion protein-based material crosslinker that underwent a stimuli- dependent conformational change. The protein used was LOV2-Jα, a species that responds to mild visible light and gives spatiotemporal control on the hy- drogel stiffness. In this work, we seek to expand the mechanical tunability of these protein-polymer-based hydrogels through well-defined mutations.