Local implantation of autologous adipose-derived stem cells increases femoral strength and bone density in osteoporotic rats: A randomized controlled animal study.

BACKGROUND: Deficient osteogenic capacity of bone marrow stem cells plays a critical role in the pathophysiology of osteoporosis. Adipose-derived stem cells (ADSCs) have emerged as a promising source of skeletal progenitor cells. The capacity of ADSCs to undergo osteogenic differentiation and induce mineralized tissue formation may be beneficial in the treatment of osteoporosis. We question whether administration of autologous ADSCs into the proximal femur of osteoporotic rats will induce osteogenesis and enhance bone quality and strength. MATERIALS AND METHODS: Thirty ovariectomized female rats were randomly assigned to one of the two treatment groups: (1) percutanous implantation of autogenous ADSCs-seeded scaffold into the proximal femur and (2) percutanous implantation of non-seeded scaffold. The contralateral untreated femur served as control. The effect of treatment on bone characteristics was assessed at 12-week follow-up by micro-computed tomography analysis, mechanical testing, and histological analysis. RESULTS: The mean cortical thickness, total bone volume density, and bone load to failure in femora injected with autologous ADSCs-seeded scaffold was significantly higher compared to femora injected with non-seeded scaffold and compared to the untreated control femora ( p < 0.01). Histological examination of the injected specimens revealed complete osseo-integration of the scaffolds with direct conversion of the ADSCs into osteoblasts and no inflammatory response. CONCLUSIONS: Autogenous ADSCs implantation into the proximal femur of rats with ovariectomy-related osteoporosis promoted bone regeneration and increased bone strength at short-term follow-up. These findings highlight the potential benefit of autogenous ADSCs in the treatment of osteoporosis. LEVEL OF EVIDENCE: Level I, randomized controlled trial, animal study.