Development of bone regeneration methods for large bone defect using bone marrow derived mesenchymal stem cells.

骨髓间充质干细胞（MSCs）具有多向分化潜能，有望用于再生医学。然而，分化能力随着其增殖时间的延长而降低。此外，我们以前的研究表明，这样的细胞不仅具有较低的骨形成能力，而且抑制骨形成。在本研究中，我们通过基因芯片和共培养的方法，以EPHA5作为抑制因子候选基因，在猴股骨骨缺损模型中应用MSCs实现了5 cm长的骨再生。再生骨具有天然骨所不具备的骨愈合能力。

Bone marrow mesenchymal stem cells(MSCs) have pluripotent differentiation capability and are expected to be used for regenerative medicine. However, the differentiation capability decreases with their prolonged proliferation. Moreover, our previous studies showed that the such cells had not only less bone formation capability but also suppressed bone formation. In this study, we focused on EPHA5 as the suppressor candidate from microarray and co-culture study.We achieved 5 cm long bone regeneration using MSCs in a monkey femur bone defect model. The regenerated bone proved its bone union capability that is one of the impossible characteristics of natural bone.