Bone regeneration with umbilical cord blood mesenchymal stem cells in femoral defects of ovariectomized rats

Abstract Objectives Current treatments for osteoporosis were prevention of progression, yet it has been questionable in the stimulation of bone growth. The mesenchymal stem cells (MSCs) treatment for osteoporosis aims to induce differentiation of bone progenitor cells into bone-forming osteoblasts. We investigate whether human umbilical cord blood (hUCB)-MSCs transplantation may induce bone regeneration for osteoporotic rat model induced by ovariectomy. Methods The ovariectomized (OVX) group (n = 10) and OVX-MSCs group (n = 10) underwent bilateral ovariectomy to induce osteoporosis, while the Sham group (n = 10) underwent sham operation at aged 12 weeks. After a femoral defect was made at 9 months, Sham group and OVX group were injected with Hartmann solution, while the OVX-MSCs group was injected with Hartmann solution containing 1 × 10 7 hUCB-MSCs. The volume of regenerated bone was evaluated using micro-computed tomography at 4 and 8 weeks postoperation. Results At 4- and 8-week postoperation, the OVX group (5.0% ± 1.5%; 6.1% ± 0.7%) had a significantly lower regenerated bone volume than the Sham group (8.6% ± 1.3%; 12.0% ± 1.8%, P  Conclusions hUCB-MSCs in bone defects may enhance bone regeneration in osteoporotic rat model similar to nonosteoporotic bone regeneration. hUCB-MSCs may be a promising alternative stem cell therapy for osteoporosis.