Repair of Bone Defects With Endothelial Progenitor Cells and Bone Marrow–Derived Mesenchymal Stem Cells With Tissue-Engineered Bone in Rabbits

PURPOSEThis study aimed to investigate the repair of bone defects in rabbits with tissue-engineered bones using cocultured endothelial progenitor cells (EPCs) and bone marrow mesenchymal stem cells (BMSCs) as seeding cells. METHODSEndothelial progenitor cells and BMSCs were isolated and purified from the peripheral blood and bone marrow, respectively, of New Zealand rabbits. The third passage of BMSCs was cultured alone or with EPCs. Cells were characterized using specific markers and then seeded on partially deproteinized biologic bones from pigs as a scaffold. The engineered bones were used to repair bone defects in rabbits. Hematoxylin and eosin and Masson staining were performed to examine vascularization and osteogenesis in the engineered bone. RESULTSThe cocultured EPCs and BMSCs grew well on the surface of the scaffold. Compared with monocultured BMSCs, cocultured EPCs and BMSCs promoted the formation of blood vessels and bone on the scaffold, in addition to accelerating the repair of bone defects. The collagen content was significantly increased in the scaffold with cocultured EPCs and BMSCs, compared with the scaffold seeded with mono-cultured BMSCs. CONCLUSIONSTissue-engineered bones seeded with cocultured EPCs and BMSCs may be used effectively for the repair of bone defects.