Visible Light-Triggered Supramolecular Hydrogel Based on Cyclic Dipeptides Stabilized with Coulomb Interactions

Amphiphilic cyclic dipeptides are efficient supramolecular hydrogelators. They can be combined with molecular photoswitches to produce light-responsive soft materials, which can be applied in controlled drug delivery. Here it is reported that an arginine-containing cyclic dipeptide decorated with ortho-fluorinated azobenzene forms hydrogels under physiological conditions that can be reversibly liquefied upon exposure to visible light frequencies (green and violet, respectively). The addition of sodium alginate results in composite supramolecular hydrogels with increased gelating capacity supported with Coulombic interactions, which also reversibly dissipate upon irradiation.