A multifunctional hydrogel with hemostatic and photothermal properties for burn repair

Effective management of burn wounds requires multifunctional dressings with integrated hemostatic, antibacterial, antioxidant, and regenerative properties. Herein, we developed an injectable hydrogel by grafting dopamine onto γ-polyglutamic acid (γ-PGA), followed by crosslinking with carboxymethyl chitosan (CMCS) via EDC/NHS chemistry. The resulting PGDA/CMCS hydrogel exhibited excellent injectability, bioadhesion, and mechanical stability (compressive modulus: 1.15 kPa), along with high swelling capacity (up to 1179%) and controlled degradation. The hydrogel showed potent ROS-scavenging activity (78.2% for DPPH˙), efficient photothermal conversion (31.05%), and enhanced antibacterial effects under NIR irradiation. In vitro assays confirmed good cytocompatibility (>90% viability) and hemocompatibility (hemolysis <5%). In vivo, the hydrogel rapidly stopped bleeding in tail and liver injury models and significantly promoted burn wound healing, especially when combined with photothermal stimulation. This multifunctional hydrogel holds strong potential for clinical use in hemorrhagic and infected wound management.