Injectable Thermoresponsive PIB/PDA/Doxycycline Hydrogels with Antibacterial, Antioxidant, and Temperature-Triggered Hemostatic Functions for Wound Healing

Injectable and thermoresponsive hydrogels integrating hemostasis, infection suppression, and oxidative stress mitigation are highly desirable for complex wound management and intravascular intervention scenarios. Herein, we developed a biocompatible and thermoresponsive hydrogel based on a poly( N -isopropylacrylamide- co -butyl methacrylate) (PIB) matrix modified with polydopamine (PDA) and loaded with doxycycline (PIB/PDA/Doxycycline). PDA endowed efficient 808 nm photothermal conversion with robust cycling stability, as well as broad-spectrum radical scavenging activity. The hydrogel enables controlled and sustained release of doxycycline over 300 h, and in vitro assays confirmed synergistic chemo-photothermal antibacterial activity against Staphylococcus aureus and Escherichia coli . In a murine full-thickness wound model, the PIB/PDA/Doxycycline achieved nearly complete wound closure with improved tissue regeneration. In a murine tail-transection bleeding model, the hydrogel rapidly formed a physical gel barrier at 37 °C, leading to a significant reduction in blood loss. This integrated hydrogel system holds promise for wound repair, antibacterial treatment, antioxidant microenvironment regulation, and temperature-triggered hemostatic applications.