Co-treatment with Basic Fibroblast Growth Factor and 17.BETA.-estradiol in the Presence of Dexamethasone Accelerates Bone Formation by Rat Bone Marrow Stromal Cell Culture

Bone marrow stromal cells (BMSCs) are a promising cell source in applications for tissue engineering and regenerative medicine. Optimization and control of the growth and differentiation of cultivated cells can be achieved by the administration of growth factors and hormones in vitro. This study provided experimental information on the enhancement of the osteogenic potential of rat BMSCs in vitro and in vivo.Mineralized nodule formation of rat BMSCs in culture for 3 weeks with dexamethasone (Dex)-treated media supplemented with both basic fibroblast growth factor (bFGF) and 17beta -estradiol (E2) was examined by histology. In porous beta-tricalcium phosphate (beta - TCP), proliferation, migration, and differentiation of BMSCs were examined by histology and transmission electron microscopy. After culturing, the composites were subcutaneously implanted into syngeneic rats. The tissues with implants were harvested after 4 weeks and evaluated microscopically by using histological stain.Dex-treated media supplemented with both bFGF and E2 was the most effective in mineralized nodule formation of BMSCs in vitro. Light and electron microscopy revealed the presence of many cells with developed rough endoplasmic reticulum. Bone formation in the BMSC/beta -TCP composites in cultures in vitro for 3 weeks was observed histologically at 4 weeks after implantation. When BMSC/beta -TCP composites were cultured in Dex-treated media supplemented with both bFGF and E2, the amount of bone formation at implants was substantially greater than that of composites cultured in Dex-treated media supplemented with bFGF.The combined use of bFGF and E2 could effectively improve the bone-forming ability of BMSCs.