Ammonium Glycyrrhizinate-Reinforced Dual-Network Poly(Thioctic Acid)-Based Hydrogel Dressing with Robust Wet Adhesion, Antibacterial Activity and Oxidative Stress Regulation

Developing hydrogel dressings that simultaneously achieve robust wet tissue adhesion, mechanical stability, antibacterial activity, and oxidative stress regulation remains challenging. In this study, a dual-network poly (thioctic acid)/ammonium glycyrrhizinate (PTA/AG) hydrogel was developed through thermally induced ring-opening polymerization (ROP) of TA and sodium thioctate (TA-Na) to form a primary network, followed by the formation of an AG-driven secondary network during cooling. TA-Na improved the aqueous processability of TA, while the AG secondary network reinforced the stability of the PTA primary network. The resulting hydrogel exhibited a crossover strain of 454% and a wet adhesion strength of up to 16.37 kPa on porcine skin. In addition, the hydrogel showed strong antibacterial activity against S. aureus (>99%), high cytocompatibility (>95% cell viability), and effective free-radical-scavenging activity (>77% scavenging of both DPPH and ABTS radicals). Notably, the hydrogel exhibited effective intracellular antioxidant activity, reducing ROS levels to near those of the control group and increasing SOD activity by approximately 13-fold and the GSH/GSSG ratio by 97.83% relative to the H2O2 group. Overall, the PTA/AG hydrogel is a promising candidate for multifunctional wound dressing applications.