Self-oxygenating, anti-freezing, antioxidant, and UV-resistant lignin hydrogels for wound healing at high-altitude

High-altitude environments significantly hinder wound healing due to low temperatures and reduced oxygen levels, leading to increased reactive oxygen species (ROS) and decreased antioxidant enzyme activity. Conventional hydrogel dressings are inadequate under these extreme conditions, as they lack cryoprotective and oxygen-generating capabilities. To address these challenges, we developed a multifunctional DL-PCaO 2 -PAM hydrogel with self‑oxygenating, anti-freezing, antioxidant, and UV-resistant properties to promote wound healing in high-altitude environments. The hydrogel was synthesized by incorporating dopamine-modified calcium peroxide nanoparticles (PCaO 2 NPs), demethoxylated lignin (DL), and polyacrylamide (PAM) using a glycerol/water binary system. This formulation enables continuous self-generation of oxygen, ensuring a sustained oxygen supply under hypoxic conditions. The anti-freeze property of hydrogel arises from the presence of phenolic hydroxyl groups and the glycerol/water system, which prevent ice formation at subzero temperatures. Furthermore, PCaO 2 NPs and DL endow the hydrogel with excellent mechanical strength, tissue adhesion, and UV resistance properties under subzero temperatures. Moreover, the DL-PCaO 2 -PAM hydrogel effectively scavenges ROS, alleviate inflammation, and accelerates wound healing in both diabetic and high-altitude hypoxic wound models. This innovative hydrogel offers a promising solution for wound care in high-altitude settings and holds potential for broader clinical applications.