Fig. 6.

Biomaterials release oxygen to promote bone repair. A) Oxygen release mechanisms of various oxygen-producing biomaterials. Reproduced and adapted with permission [147]. Copyright 2021, Elsevier. B) A novel composite hydrogel scavenges ROS and prolongs oxygen production to reverse the hypoxic microenvironment in areas of bone defects. Reproduced and adapted with permission [90]. Copyright 2022, Elsevier. C) 3D-printed bionic oxygen-containing scaffolds enhance the expression of osteogenic regulatory transcription factors and accelerate osteogenesis. Reproduced and adapted with permission [91]. Copyright 2022, American Chemical Society.