Expansion of Human Marrow Derived Mesenchymal Stem Cells and their Transdifferentiation Potential

Background: The ability of mesenchymal stem cells (MSCs) to differentiate into other cell types makes these cells an attractive therapeutic tool for cell transplantation. In order to provide a source of human MSCs for autologus cell-based therapy, we have expanded MSCs from the bone marrow and analyzed the biological identities and transdifferentiation potential. Methods: The bone marrow of healthy donors was aspirated from the iliac crest. The adjacent cells expanded rapidly and maintained with periodic passages until a relatively homogeneous population was established. The identification of these cells was carried out by differentiation potential into the osteocytes and adipocytes. Transdifferentiation of human MSCs into hepatocyte-like cells was undertaken in response to a specific culture condition. Results: The differentiation of MSCs into osteoblast is determined by deposition of a mineralized extracellular matrix. Adipocytes are identified by their morphology and staining. Hepatic cells were demonstrated in vitro functions characteristic of liver cells. Conclusion: We have defined conditions under which human MSCs can be isolated and expanded from human bone marrow. These cells can be amplified about 108-fold in 6 weeks, and are capable of transdifferentiation into the cells of another developmental lineage.