Multifunctional Poly(thioctic acid) Composite Hydrogels with Self-Healing, Antibacterial, Antioxidant, and Adhesive Properties

Bacterial infections and excessive reactive oxygen species (ROS) severely impede wound healing. However, traditional hydrogels often lack the integrated antibacterial and antioxidant properties required for effective treatment. To overcome these limitations, a natural thioctic acid (TA)-based multifunctional composite hydrogel (PTA-Arg/SAS) was developed. Arginine (Arg) served as a green inducer for the aqueous ring-opening polymerization of TA. Concurrently, salicylic acid-grafted sericin (SAS) was introduced to inhibit poly(thioctic acid) (PTA) depolymerization via the formation of stable sulfur-aryl (S-Ar) bonds. The hydrogel exhibits self-healing capability, injectability, and robust tissue adhesion to porcine skin (1877 Pa dry; 1663 Pa wet). Furthermore, SAS endowed the system with potent antibacterial (99.1% against E. coli, 97% against S. aureus) and antioxidant activities (98.2% ABTS and 72.7% DPPH radical scavenging rates). In vitro evaluations confirmed the viability of L929 cells (>98% over 3 days) and a negligible hemolysis ratio (<5%). Consequently, this study provides a strategy for fabricating next-generation bioactive dressings for complex wound management.