A light responsive single amino acid-based supramolecular hydrogel for photo-controlled vitamin release

Abstract

Light responsive low-molecular-weight hydrogelators (LMWHs) offer a promising platform for controlled delivery applications via light triggered structural changes in the hydrogel network. In this study, we report the facile synthesis of a tyrosine-derived LMWH, FmocY-Azo, incorporating a photoresponsive azobenzene moiety. Self-assembly of FmocY-Azo under ambient conditions provides the supramolecular hydrogel material that displays thixotropic behavior, as well as thermal and light responsiveness. The hydrogel material effectively encapsulates vitamin B₁₂ within its fibrous network and enables its controlled release upon light irradiation, driven by structural changes in the FmocY-Azo framework. The release kinetics follows the Korsmeyer–Peppas model in the presence of light irradiation, whereas it follows zero-order kinetics in the dark, indicating a combined effect of diffusion and light-induced network disassembly. This work presents a single amino acid-based light responsive fibrous hydrogel with potential for developing light-triggered drug delivery systems.