Cell membrane vesicles derived from hBMSCs and hUVECs enhance bone regeneration.

Bone tissue renewal can be enhanced through co-transplantation of bone mesenchymal stem cells (BMSCs) and vascular endothelial cells (ECs). However, there are apparent limitations in stem cell-based therapy which hinder its clinic translation. Hence, we investigated the potential of alternative stem cell substitutes for facilitating bone regeneration. In this study, we successfully prepared cell membrane vesicles (CMVs) from BMSCs and ECs. The results showed that BMSC-derived cell membrane vesicles (BMSC-CMVs) possessed membrane receptors involved in juxtacrine signaling and growth factors derived from their parental cells. EC-derived cell membrane vesicles (EC-CMVs) also contained BMP2 and VEGF derived from their parental cells. BMSC-CMVs enhanced tube formation and migration ability of hUVECs, while EC-CMVs promoted the osteogenic differentiation of hBMSCs in vitro. Using a rat skull defect model, we found that co-transplantation of BMSC-CMVs and EC-CMVs could stimulate angiogenesis and bone formation in vivo. Therefore, our research might provide an innovative and feasible approach for cell-free therapy in bone tissue regeneration.