Local Transplantation of Ex-vivo Expanded Bone Marrow-derived CD34 Positive Progenitor Cells Accelerate non-Union Fracture Healing

Accelerate non-Union Fracture Healing + 1, 2 Y.Kawakami; 1 M. Ii; 2 T.Matsumoto; 1 A.Kawamoto; 1, 2 T.Shoji; 1, 2 Y.Mifune; 1, 2 T.Fukui; 2 R.Kuroda; 2 M.Kurosaka; 1 T.Asahara + 1 Group of Vascular Regeneration Research, Institute of Biomedical Research and Innovation, Kobe, Japan. + 2 Department of Orthopedic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan. [email protected] INTRODUCTION Failures in fracture healing are mainly caused by a lack of neovascularization. We have previously demonstrated that local transplantation of G-CSF-mobilized peripheral blood (GM-PB) CD34+ cells, an endothelial/hematopoietic progenitor enriched cell population,(1) contributed to fracture healing via vasculogenesis and osteogenesis. (2),(3) However, the scarcity of CD34+ cells in PB and the biological side effect of G-CSF administration and apheresis still remain to be possible problems in clinical settings. In terms of expanding clinical application, we postulated the hypothesis that local transplantation of same number of not only bone marrow (BM) CD34+ cells but also culture expanded BM-CD34+ cells as that of GM-PB CD34+ cells might exhibit similar or more potent therapeutic potential for fracture healing without increasing the original number of cells for transplantation. In this study, we performed a series of experiments to compare the therapeutic effects of local transplantation of expanded BM CD34+ cells, BM CD34+ cells and GM-PB CD34+ cells using a rat unhealing fracture model.