Types of Stem Cells
There are various types of Stem Cells that exist in the human body. The most commonly used stem cells in therapies for numerous universally prevalent disorders revolve around two main types of stem cell families, HSC and MSC. These are further classified depending upon the specific marker they possess. Depending upon the marker they possess.
Total Cord Blood Transplants
Hematopoietic Stem Cells (HSC) are found mostly in the bone marrow but also in peripheral blood, cord blood etc. These cells are unspecialized and hematopoietic or blood forming by nature. Thus it generally gives rise to blood forming cells eg. red blood cells, white blood cells etc. However when subjected to certain conditions and in certain environments it gives rise to the organ or tissue that has been impaired due to the unique property of homing , plasticity and engraftment. It can then potentially completely repair and regenerate the damaged tissue and/or organ. It however requires a suitable micro-environment consisting of probably other white cells and mesenchymal cells for optimum affectivity. Common types of stem cells that contain hematopoietic stem cell surface markers include CD34, CD45, CD133.
Mesenchymal Stem Cells (MSC) are bone marrow populating cells, different from hematopoietic stem cells, that are present in the stroma they possess an extensive proliferative potential and ability to differentiate into various cell types including, osteocytes (bone), adipocytes (fat), chondrocytes (cartilage), myocytes (muscle), cardiomyocytes (cardiac muscle) and neurons (nerves) and blood vessels. They play a vital role in the formation of nerves, muscles, fat, blood vessels, bones, cartilage etc. of the body and hence obviously play an extremely vital role in their regeneration as and when required. Trauma, disease or disorder directly or indirectly afflicting any of these tissues requires mesenchymal stem cells to urgently swing into action to facilitate their repair and recovery. MSCs also play a key role in the maintenance of bone marrow homeostasis and regulate the maturation of both hematopoietic and non-hematopoietic cells. MSCs have been shown to be powerful tools in gene therapies. Due to such characteristics, the number of clinical trials based on the use of MSCs in on the increase. These cells have been successfully employed in graft-versus-host disease (GvHD) treatment, heart regeneration after infarct, cartilage and bone repair, skin wounds healing, neuronal regeneration and many others. MSCs are particularly important in medical research as they represent a powerful tool in the future of re-generative medicine. Common types of stem cells that contain mesenchymal stem cell surface markers include CD73, CD90, CD106.
Apart from the bone marrow, MSCs are also located in other tissues of the human body viz. adipose, liver, lung and fetal tissues. There are an increasing number of reports describing their presence in the unbilical cord blood, chorionic villi of the placenta, amniotic fluid, peripheral blood and even in exfoliated deciduous teeth.