Oxygen-releasing wound dressings: from molecular mechanisms to smart therapeutic platforms

Oxygen is a key regulator of cellular homeostasis, metabolism and tissue repair, orchestrating important biological processes such as energy production, angiogenesis, collagen cross-linking and immunomodulation. Chronic and infected wounds are characterized by persistent hypoxia and impaired neovascularization that affect cellular function, prolong inflammation and increase susceptibility to microbial colonization. Localized oxygen supplementation has been developed as a promising therapeutic strategy to facilitate fibroblast proliferation, keratinocyte migration and effective bacterial clearance while maintaining redox balance and improving tissue perfusion. Recent advances in oxygen-generating wound dressings have offered spatiotemporally controlled oxygen release tailored to the wound-specific dynamics, encompassing peroxide-based generators, enzymatic systems, hemoglobin-based and perfluorocarbon oxygen carriers, photo- and electrochemical oxygenation platforms, and micro- and nanobubble technologies. Furthermore, the smart infection-responsive dressings that control oxygen release based on the bacterial load or pH changes are a major step towards personalized wound care. This review comprehensively discusses the physiological role of oxygen in dermal regeneration, critically evaluates the mechanisms, release kinetics, and biocompatibility of current oxygen delivery technologies, and highlights future perspectives for clinical translation of smart oxygenating wound dressings in treating chronic and diabetic wounds.