Oxygen-releasing scaffolds in tissue engineering: design strategies, fabrication and regenerative applications

Oxygen is indispensable for sustaining tissue and cell physiological functions, yet a hypoxic microenvironment often arises in tissue injury and regeneration, impairing graft scaffold performance and hindering repair processes. Thus, oxygen-releasing scaffolds have become a pivotal research frontier in tissue engineering. Via elaborate spatial constructions (e.g. electrospun fibers, hydrogels, microspheres) and diverse modification strategies, these scaffolds enable sustained, spatiotemporally controllable oxygen release at injury sites, alleviating local hypoxia and boosting tissue regeneration. They show great application potential in repairing skin, bone, nerve and cardiovascular tissues, as well as in tumor therapy, though comprehensive systematic summaries of their tissue engineering applications remain scarce. This review aims to delineate domain advances systematically: it first gives a holistic overview of core aspects, including oxygen carrier categories and delivery mechanisms, scaffold material modification and functionalization, intelligent responsiveness optimization and reactive oxygen species scavenging paradigms, then comprehensively recapitulates their application status and therapeutic efficacy across diverse scenarios (skin wound repair, bone defect regeneration, nerve injury remediation, tumor therapy, cardiovascular tissue reconstruction); finally, dissects practical application challenges and proposes future development trends, expecting to provide valuable references for in-depth research and clinical translation of oxygen-releasing materials in tissue repair and reconstruction.