Coassembly Modulated pH-Responsive Hydrogel for Dye Absorption and Release

Hydrogel as a carrier for drug delivery system has been developed, but it is hard to change the load and release of drugs through a simple way. Herein, the authors report a novel pH-sensitive supramolecular binary hydrogel based on Phe-Gly derivative gelator (LPPG) and 4,4′-dipyridine disulfide (DPDS). Fourier transform infrared spectroscopy, circular dichroism, and 1 H NMR confirm that the driving force for the coassembly process is intermolecular hydrogen bonds. The composite hydrogel can improve the dye adsorption capacity relative to LPPG hydrogel. Moreover, the controllable absorption of the dyes is studied by varying the pH and concentration of dye solutions. LPPG-DPDS hydrogel can also release of entrapped dyes at physiological pH. The two-component hydrogel should be a promising system for controllable drug delivery.