At the very beginning of stem cell research Bone Marrow was the sole source. As it had some faltering effects, scientists moved on for embryonic stem cells. Again as because of the ethical issues, stem cell source changed its course towards umbilical cord blood cells. Presently three more sources are discovered as Placental Stem cell, dental stem cell and Menstrual Blood Stem cell. Each of these sources have their individual advantages and disadvantages. Lets see how according to situation and condition each of them complements each other.
Bone marrow stem cell are obtained from the long bones generally. The best sources are pelvic bones, femur (thigh bone) and sheen bone. The bone marrow stem cells are adult stem cells and therefore not as diversified and potent to differentiate as compared to embryonic stem cells. Although they avoid the controversies related to embryonic stem cells, they are not as efficient as the later. But a number of success stories are heard in the press releases and therefore it is the most convenient source for stem cell.
Embryonic cells are obtained from the blastocyst phase of the embryo. Cells are highly efficient in producing newer types of cells. They are more diversified than the adult stem cells. Moreover this advantage can be explained more vividly if we concentrate on the telomere (tail of chromosome) length. Adult stem cells having shorter tail lengths, do not live long.
In order to find a solution to the ethical problems, scientist found a new source of stem cells which can be more effective than bone marrow stem cells and not indulging into any controversy - umbilical cord blood stem cells. These stem cells are obtained from the umbilical cord blood, which are collected just after the birth of the baby. Umbilical cord is a tube like structure that connects the fetus (unborn baby) to the mother’s womb through which it received nutrition, respirator gases and immunological support. In early days, this cord blood was rejected, but it was found later to be so effective in stem cell therapy.
Today there are many cord blood banks who preserve these, and supply stem cells during operations in different hospitals as they require. But there is a problem too.
The amount of cord blood is only 180ml and is insufficient for treating an adult with a single unit of cord blood. Also the growth rate of these stem cells are also low.
Then scientist focused on placental stem cell. This is another organ which was rejected earlier but now they are used successfully in obtaining stem cells. Placenta is an organ which is a part of mother’s womb. This connects the womb to the umbilical cord. It provides almost all the life supports to keep the baby alive. So after birth it has been found to give rise to more number of stem cells as compared to embryonic stem cells. It also clearly surpasses the ethical obstacles.
There is a skepticism about one matter which is still under study, and we would say that it is a major concern, is that, placental stem cells after a single division give rise to immunological problems. But to be more sure about the information we need to wait.
Stem cells are also been reported to be produced from unconventional sources such as menstrual blood and teeth. Doesn’t it sounds interesting?
Menstrual stem cells have an extra-ordinary improvement over the umbilical cord blood cells. They have a rapid growth rate which was missing earlier and in that respect umbilical cord blood was failing every time. Now as researches are going on delving deep into it, we can hope to find a speedy introduction of it into medical application.
Dental stem cells are cells obtained from tooth pulp generally from babies or from wisdom teeth. This has been found to produce bones, cartilage, muscle cells if cultured. The major advantage over other types is that, these stem cells are easier to collect. Also being adult stem cells it does not face the controversies.
Therefore the different sources are quite well complementing each other and it is very cheering to find that sources vary upon different condition and phases of a particular disease. In near future we are optimistic to find newer sources in order to add to the efficiency of stem cell research and therapy.