Design and characterization of a bioinspired green lipoic acid–syringic acid-based hydrogel for wound healing

Abstract

In this study, we have developed a green hydrogel composed of α-lipoic acid (LA) and syringic acid (SA) for wound healing applications. LA, known for its antioxidant properties, was polymerized through thermally initiated ring-opening polymerization (ROP) to form a poly-LA hydrogel, while SA was incorporated to enhance adhesion and bioactivity. The optimal hydrogel formulation (LA : SA 1 : 0.1) exhibited improved adhesivity and gelation, as confirmed by rheological analysis. Comprehensive characterization using nuclear magnetic resonance spectroscopy (NMR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM) verified the successful cross-linking, amorphous nature, and interconnected morphology of the hydrogel. The functional assays demonstrated that the poly-LA–SA hydrogel (LAS-G) exhibits higher antioxidant activity, as evidenced by DPPH (92.33%) and ABTS (70.92%) radical-scavenging, as well as a significant antibacterial effect against Staphylococcus aureus and Escherichia coli, compared to the native poly-LA hydrogel (LA-G). In vivo studies in a rat incisional wound model revealed that LAS-G accelerated wound closure, enhanced collagen deposition, and improved tissue regeneration. The synergistic effect of LA and SA contributes to improved gelation and biological properties, positioning LAS-G as a promising approach for advanced wound care. These findings indicated that LAS-G provides a safe, effective, and multifunctional strategy for promoting wound healing and tissue repair.