Transplantation of bone-forming cells

The transplantation of bone forming cells in eludes the transfer of discret e pieces of viable bone and of ex vivo expanded osteoprogenitor cells. Thes e progenitor cells, derived from bone marrow stroma, have been termed bone marrow stromal cells (BMSCs), BMSCs are pluripotent cells with several dist inct phenotypes including bone, cartilage, fat, and muscle. In vitro and in vivo analyses of BMSCs have been utilized to discern the in fluence of the donor and of growth factors on BMSC proliferation and differ entiation. In vitro parameters utilized to evaluate cultured BMSCs include colony morphology, cell morphology, bone specific and bone related proteins , and enzyme expression. In vivo analyses historically have utilized diffus ion chambers, implants beneath the renal capsule, and, most recently, subcu taneous implants. In anticipation of their potential clinical ap plications, BMSCs have been used to close bone defects in animals and as vehicles for gene mediated the rapy. However, limited success to date in the latter effort suggests that f urther innovation and investigation is warranted.