Triple functional magnesium ascorbyl phosphate encapsulated hydrogel: A cosmetic ingredient promotes bone repair via anti-oxidation, calcium uptake and blood vessel remodeling

Bone defect repair involves a synergistic repair process involving the reconstruction of the skeletal system and remodeling of the neurological and vascular systems. However, current strategy/systems are mainly single function/purpose for bone repair. In this study, we propose a strategy that utilizes a simple but multifunctional cosmetic ingredient magnesium ascorbyl phosphate (MAP), for effective in situ cranial defect repair. MAP is loaded into a gelatin methacrylate hydrogel to achieve sustained release and the scaffold supply only phosphorus-containing compounds to promote bone repair without an exogenous supply of Ca2+. Results show that MAP can reduce oxidative stress damage in bone marrow-derived mesenchymal stem cells (BMSCs) by scavenging reactive oxygen species and promoting Ca2+ uptake to accelerate the mineralization of BMSCs in vitro. In addition, the pro-angiogenic and ERK/AKT signaling pathway activation abilities of MAP accelerate the biological process of bone defect repair. Micro-CT result reveal a greater repair rate in the 8-week MAP group (32.74 ± 0.62%) than in the control group (7.08 ± 0.29%). This study suggests that inorganic-phosphorus-based small-molecule delivery and calcium-free strategies have considerable potential in bone defect repair.