Oxygen Delivery Biomaterials in Wound Healing Applications.

Oxygen (O 2 ) delivery biomaterials have attracted great interest in the treatment of chronic wounds due to their potential applications in local and continuous O 2 generation and delivery, improving cell viability until vascularization occurs, promoting structural growth of new blood vessels, simulating collagen synthesis, killing bacteria and reducing hypoxia-induced tissue damage. Therefore, different types of O 2 delivery biomaterials including thin polymer films, fibers, hydrogels, or nanocomposite hydrogels have been developed to provide controlled, sufficient and long-lasting O 2 to prevent hypoxia and maintain cell viability until the engineered tissue is vascularized by the host system. These biomaterials are made by various approaches, such as encapsulating O 2 releasing molecules into hydrogels, polymer microspheres and 3D printed hydrogel scaffolds and adsorbing O 2 carrying reagents into polymer films of fibers. In this article, different O 2 generating sources such as solid inorganic peroxides, liquid peroxides, and photosynthetic microalgae, and O 2 carrying perfluorocarbons and hemoglobin are presented and the applications of O 2 delivery biomaterials in promoting wound healing are discussed. Furthermore, challenges encountered and future perspectives are highlighted.