Reversibly Photocontrolled Polymer Networks Through Photoswitchable Dynamic Covalent Bonds

In polymer networks based on dynamic covalent bonds, changes in reactivity can be translated into macroscopic responses. Light offers precise, tunable, and noninvasive spatiotemporal control over molecular reactivity. The Kalow lab has designed crosslinks that allow us to tune the thermodynamics and kinetics of dynamic covalent bonds with light, including visible light, based on the conformation of an adjacent photoswitch. When incorporated into polymer networks, the stability or lifetime of these dynamic covalent bonds can be tuned with light. I will discuss the molecular mechanisms underlying these macroscopic changes, as well as rational optimization of photoswitches to enable applications in 3D cell culture.