Development of an Injectable Synergistically Crosslinked Polysaccharide Hydrogel with Antioxidant and Antibacterial Properties for Promoting Wound Healing.

The development of wound dressings that concurrently exhibit excellent injectability, antibacterial performance, and tissue adhesion is essential for the effective treatment of hard-to-heal wounds. Polysaccharide-based hydrogels have become a research hotspot due to their favorable biocompatibility and tunable functional properties. In this study, an in situ-forming hydrogel (QDTA) is fabricated by blending quaternized chitosan (QCS), tannic acid (TA), and difunctional polyethylene glycol (DF-PEG), utilizing both physical crosslinking and dynamic covalent bonding. The QDTA hydrogel demonstrated a suitable gelation time (60-240 s) and exhibited significant antibacterial activity against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), with average inhibition rates of 98.96% and 98.91%, respectively. Moreover, it showed a biodegradation rate of up to 90% within 10 days, making it suitable for in vivo wound healing applications. In vivo experiments further confirmed that QDTA hydrogel effectively promoted tissue regeneration and wound healing by exerting antibacterial effects, scavenging reactive oxygen species (ROS) in the wound site, and enhancing cell migration, ultimately achieving a wound closure rate of ≈99.75% by day 14. These results highlight the significant potential of QDTA hydrogel as an effective wound dressing for clinical application.