Lignin-Mediated Dual Conductive Hydrogels with High Conductivity, Antibacterial Activity and Biocompatibility for Chronic Wound Repair

In recent years, conductive polymer hydrogels based on polypyrrole (PPy) combined with electrical stimulation (ES) have emerged as a promising approach for chronic wound repair. However, in practical applications, PPy often exhibits limitations such as poor water dispersion, weak inherent conductivity and a lack of biological functionality. To address these challenges, this study proposes an innovative design of a conductive hydrogel that employs a natural biopolymer, lignin sulfonate (Lgs), as both a dispersant and dopant for PPy, while incorporating silver nanoparticles (Ag NPs) to confer the hydrogel antibacterial properties. The results showed that the water dispersion of PPy was significantly improved, and the conductivity of the hydrogel was as high as 2.82 ± 0.04 mS/cm through the double conduction mechanism of PPy and Ag NPs. The hydrogel exhibited antibacterial activity against Escherichia coli (<i>E. coli</i>) and Staphylococcus aureus (<i>S. aureus</i>), and the antibacterial rate could exceed 90%. In vitro tests demonstrated that the hydrogel exhibited good biocompatibility, adhesion ability (7.97 ± 0.56 kPa) and hemostatic ability. Furthermore, in vivo animal experiments showed that the hydrogel combined with ES achieved 93.71 ± 2.46% wound closure within 14 days, which can significantly accelerate wound healing, promote collagen deposition and epithelial tissue regeneration. These findings demonstrate that the developed hydrogel can serve as an effective platform for ES-assisted chronic wound repair.