Background: Since their initial description by Friedenstein et al. 30 years ago, mesenchymal stem cells have been characterized as a cell population of the bone marrow, which is easily accessible and readily manageable for in vitro manipulation.
Results: Cell biology studies have delineated the phenotype of mesenchymal stem cells, optimized the conditions for in vitro expansion, and documented their differentiation capacity along mesodermal lineages. First clinical applications as an adjunct to stem cell transplantation regimens have shown some potential in osteogenic regeneration as well as immunosuppressive effects after allogeneic stem cell transplantation. Animal studies have further shown, that mesenchymal stem cells may serve as vehicles for the transfer of genetic material. Preclinical studies remain, however, to answer numerous questions with regard to populational heterogeneity and the physiological roles of this cell compartment.
Conclusion: Further preclinical studies as well as clinical cell therapy studies are essential to fully exploit the potential of mesenchymal stem cells in regenerative medicine, cellular immunotherapy, and gene therapy.