Oxygen-Releasing Hydrogel Patches Restore pH Balance and Support Cell Survival in Acidic Oral Wound Models

Low-pH and hypoxic conditions commonly develop in oral surgical sites and mucosal wounds, impairing cell viability and delaying healing. This study presents a simple, cell-free, and clinically translatable hydrogel patch incorporating microencapsulated calcium peroxide granules to locally deliver oxygen and buffer acidity. Calcium peroxide particles in the range of 50 to 150 micrometers, were coated with a thin PLGA shell to moderate reactivity and embedded into a GelMA-AlgMA composite membrane. In acidic artificial saliva, pH 5.2, patches containing 0.25% calcium peroxide released oxygen steadily for up to 8 hours and restored pH to physiological levels within 90 minutes. When applied to a DPSC-seeded collagen wound model exposed to lactic-acid challenge, the patches significantly improved metabolic activity and cell viability compared to acidified controls, without signs of cytotoxicity. These findings indicate that calcium peroxide-integrated hydrogels offer a low-cost, practical approach to counteract hypoxia and acidosis in oral wound environments, supporting early regenerative processes and providing a translationally viable platform for future preclinical development.