There are some stem cells in almost every tissue in the body. In order to obtain them in numbers high enough to treat, two things have to be present:
- The tissue or area has to be easily accessible.
- The tissue or area has to have a large enough number of stem cells to enable collecting or harvesting enough to receive a therapeutic response.
The first area found in adults with these criteria was bone marrow. Stem stems from bone marrow are called hematopoietic stem cells (HSC). Since these were first discovered and isolated, many studies have been done and some treatments developed. Some blood derived diseases and leukemia and myelodysplasia are now treated commonly with bone marrow transfer. Bone marrow transfer relies on the stem cells (HSC) present in the donor’s blood for its effectiveness.
As mentioned above, in the United States this represents one of the first effective therapeutic uses of stem cells. More recently, fat has been found to have large numbers of stem cells. Fat is easily harvested under local anesthesia using a form of liposuction. Fat can also produce much larger numbers of stem cells from a single –procedure.
A typical bone marrow stem cell harvest yields around 60,000 stem cells. These then need to be cultured for 2-3 days in order to have the 2-3 million stem cells usually required for effective deployment. A single 25-milliliter syringe of fat can yield 10-30 million stem cells without the need to culture or grow more. Fat derived stem cells are called adipose-derived stem cells (ADSC).
Some controversy exists around whether adipose or fat derived stem cells area as effective as bone marrow derived stem cells. Studies have shown that the two types of cells have very similar characteristics and therapeutic potential (1,2) . This makes autologous adipose derived stem cells the easiest and most likely source for future stem cell usage.
1. Cell Tissue Res. 2012 Nov;350(2):277-87. doi: 10.1007/s00441-012-1453-1. Epub 2012 Jun 5. The comparition of biological characteristics and multilineage differentiation of bone marrow and adipose derived Mesenchymal stem cells. Zhu X, Shi W, Tai W, Liu F.
2. Clin Lab. 2012;58(9-10):897-903.