Stem cells are progenitors of specialized cells, such as blood, skin, liver, mucosa and other cells body organs and tissues are made of. Since specialized cells can only live for a certain period of time, their count in the body should be maintained continuously. Acting as a repair system, stem cells can asymmetrically divide producing a mother cell ensuring self-replication and a new cell capable of differentiation into a specialized cell.
Stem cells vary by their differentiation potential, which is the highest for the fertilized egg, or zygote, capable of differentiation into any cell type of the body and extra embryonic tissues. Over the next 7-12 weeks, this potential is maintained. While they develop, stem cells become more specialized, and their differentiation potential decreases.
In our clinic we use 7-12 weeks old fetal stem cells with very high differentiation potential. They can differentiate into the wide trange of cell types within the certain germ layer – ectodermal, endodermal or mesodermal. Moreover, stem cells we use have higher proliferative potential compared to other types of stem cells (adult stem cells, cord blood stem cells etc.)
At the same time, stem cells we use have already undergone specialization in the germ layers, lost their capacity for uncontrolled growth and "know for sure" what cell or tissue type they should differentiate into. Fetal stem cells (7-12 weeks old) are different from embryonic stem cells (4–5 days post fertilization) capable of uncontrolled growth that can result in teratomas. We have no cases or history of post-treatment tumor development in our patients.
Moreover, rejection is also not an issue with fetal stem cells as HLA expression in them is either absent or minimal, while adult and cord blood stem cells do express histocompatibility antigens, which requires donor-recipient HLA matching or immunosuppression.
After week 12, stem cells undergo further specialization resulting in the development of more specialized stem cells that can be found both in the fetus, newborn, and adult body. For instance, hematopoietic stem cells found mainly in the bone marrow are responsible for continuous formation of the new blood cells substituting the destroyed ones. They give rise to two lines of more specialized stem cells that, in the process of further specialization, keep differentiating until they form erythrocytes, monocytes, B- and T-lymphocytes, and other cell types.
As we age, stem cell count in the body decreases. For a newborn, stem cell ratio stands at 1/10,000, for teenagers at 1/100,000, by the age of 50 it amounts to 1/500,000, and by the age of 70 only to 1/1,000,000. Therefore, the issue of cell pool replenishment and activation of one’s own stem cells is the key for finding solutions on how to live longer, stay young and treat a wide range of diseases caused by cell count depletion.
Administered into the recipient’s body, fetal stem cells can migrate to the site of damage, engraft, proliferate, undergo specialization under regulation of a new host tissues and substitute for lost or damaged cells, thus restoring the impaired body functions. Moreover, fetal stem cells can produce considerable amounts of biologically active substances, e.g. hematopoietic growth factors, interleukins, nerve growth factor, tumor necrosis factors, angiogenic and neurotrophic factors, etc.