Magnesium Oxide Nanoparticle Coordinated Phosphate-Functionalized Chitosan Injectable Hydrogel for Osteogenesis and Angiogenesis in Bone Regeneration

release in a stable and sustained manner. The CSMP-MgO injectable hydrogels promoted in vitro calcium phosphate (hydroxyapatite (HA) and tetracalcium phosphate (TTCP)) deposition in supersaturated calcium phosphate solution and presented no cytotoxicity to MC3T3-E1 cells; the CSMP-MgO hydrogel promoted MC3T3-E1 cell osteogenic differentiation with upregulation of BSP, OPN, and Osterix osteogenic gene expression and mineralization and HUVEC tube formation. Among them, CSMP-MgO (5) presented most of these properties. Moreover, this hydrogel (CSMP-MgO (5)) showed an excellent ability to promote new bone formation in critical-sized calvarial defects in rats. Thus, the CSMP-MgO injectable hydrogel shows great promise for bone regeneration.