Stem cells are so-called undifferentiated cells that can be transformed into various body cells – and there are more than two hundred of them in humans – with various inherent functions. For example, nerve cells or blood cells obtain narrow, specific tasks – and they spend all their energy on performing these tasks, without wasting on reproduction. New red blood cells or neurons arise from stem cells that every person at any age has. They are of various kinds: some are able of differentiating only into one type of cells, others into several; embryonic stem cells in early pregnancy can be transformed into any type of body cell.
There is a terminological discussion among scientists about whether all these cells can be known stem cells and whether the terms “stem cell” and “progenitor cell” are synonymous, but in general, both terms can be applied equally. We are talking about basic cells that can be transferred into any other – which means, if you learn how to handle them correctly, they can potentially allow you to grow new skin at the site of a burn or replace liver tissue affected by hepatitis. Unfortunately, it is not yet possible to use stem cells for such purposes – but still there are a number of severe problems that they help to solve. Stem cells can be obtained from embryos (for example, abortive materials can be used for research purposes), and in adults, their main source is bone marrow. Stem cells are also actively secreted from dental pulp and from the umbilical cord of newborns.
Stem cells have been used for several decades in the treatment of severe diseases of the blood and bone marrow, such as leukemia. The bone marrow is an organ of hematopoiesis; in fact, it comprises of stem cells. When it is not functioning or produces “defective” blood cells, one of the treatment options is transplantation, that is, “replacing” the bone marrow stem cells with healthy ones. For this, both donor cells and their own can be used, if they have undergone a certain processing.
The bone marrow transplant procedure itself is not like a classical transplant – the doctor does not cut the bones and replace their contents with new ones. A bone marrow transplant looks like a blood transfusion – by the way, bone marrow donation can be done as a blood donation. With other tissues, the situation is still more complicated: for a skin or corneal transplant, tissue from stem cells must first be grown in a nutrient medium, and these are expensive processes that require ideal conditions. According to the researchers, the states are not yet ready to finance such methods, and for commercial structures it is not very profitable due to the relatively low demand.
As with any potential cure or a means of rejuvenation, an expensive business has formed around stem cells: more and more services are offered to isolate and store stem cells “just in case.” Indeed, the same dental stem cells have great potential – but no one knows when they can be used in practice to treat, for example, heart disease. Dentists are already offering a service for freezing them. Such services are usually sold with the wording “if you develop a rare disease, stem cells will save your life” – but it is not a fact that in this case they will already be used to treat a specific disease.
Another common option is the cord blood bank; in order to preserve stem cells in it, the umbilical cord must be cut as soon as possible after the child’s birth, literally within a couple of seconds. These banks are of two types: private and public (most often with government funding). Blood is donated to a public bank for free – but a specific child will no longer be able to use it. The sample is anonymized for storage, fully describing its characteristics, and may after some time be issued at the request of a particular hospital for transplantation. Cord blood and stem cells from public banks can also be used for research purposes.
In a private bank, you have to pay for storing blood, but if necessary – for example, if a child has been diagnosed with leukemia – your own stem cells can really save a life. True, so far, according to researchers, the likelihood that a person will develop a disease before the age of 21, which can be cured by his own stem cells, ranges from 0.005% to 0.04% – that is, tends to zero. The likelihood that stem cells will be useful for treating someone from blood relatives is even lower. These rates are likely to rise when stem cells actually begin to be used in the treatment of common diseases such as strokes or diabetes mellitus. But today the services of a private cord blood bank are just a way to spend a lot of money.