Exosomes Derived from Mg-Preconditioned Bone Mesenchymal Stem Cells Promote Angiogenesis and Osteogenesis for Osteonecrosis Treatment.

Steroid-induced osteonecrosis of the femoral head (SONFH) is a common and refractory orthopedic disorder, often resulting from prolonged or high-dose glucocorticoid use that impairs bone repair and vascularization. The critical impact of exosomes derived from bone mesenchymal stem cells (BMSCs) in bone regeneration has drawn increasing attention. In this study, we developed a novel type of exosomes derived from Magnesium-preconditioned BMSCs (Mg-Exos) and evaluated their therapeutic potential. In vitro experiments demonstrated that Mg-Exos effectively counteracted Dex-induced impairment in the angiogenic function of human umbilical vein endothelial cells (HUVECs) and the osteogenic differentiation of BMSCs. These findings highlight the promise of Mg-Exos as a potential cell-free therapeutic strategy for SONFH, acting through the concurrent enhancement of vascularization and bone formation. Consequently, this work lays a solid foundation for the future application of Mg-Exos in treating SONFH.