Cell transplantation is one of the actively developing trends of regenerative medicine. Its aim is defective organ cells replacement to restore functional activity and integrity.
    Contemporary medicine allows to compensate tissues or organs functions or tries to prevent development of a disease. These methods are a temporary solution and not really effective. Insulin therapy of diabetes is the most striking example. Insulin injection helps to retain the organs vital function of glucose consumption but doesn't prevent from other complications of the disease. The injured cells, that determine the organs functionality, should be replaced to reach the constant therapeutic effect and restore its integrity. So scientists have high hopes for cell transplantation. The cells are believed to get alive and repair the defect. The regeneration can occur both due to the implanted cells that begin to divide and produce different factors and to innate stem cells. In the last case the injected cells start to stimulate organ stem cells to proliferate and repair the defect. But actually these processes are not separated and supplement each other. In some cases cells should be introduced into the defect area, but they can be also injected intravenously, because they are able to migrate and repopulate the damaged tissue. This feature is called homing and is particularly described for hemopoietic stem cells.

     Nowadays the most well-known cell transplantation is bone marrow- and HSC-grafting. These operations are essential not only for hematology, but also for oncology and clinical genetics. Bone marrow and HSC transplantation is performed to restore the hemopoiesis of the patients who somehow lack this bone marrow function. This is the way that functional integrity of the organ recovers. The effect and value of these operations is hard to overestimate because they have saved more than ten thousands lives.

    Nowadays many tissue-specific stem cells are isolated and characterized (epidermal, endothelial, neural stem cells and others), different techniques to use this material in clinic have been developed. Mesenchymal stem cells isolated from bone marrow or adipose tissue stand out from all these cell types. MSC have special immunologic features, for example, they are able to suppress the activity of special immune system cells (T-cells, B-cells, dendritic cells and natural killers). This beneficial feature of MSC allows to lower the risk of immunological reaction occurrence after allogenic transplantation. Multilineage differentiation promotes the regenerative medicine development to restore tissues and organs with the help of MSC.