As the name would suggest, the study related to embryonic stem cells is known as embryonic stem cell research. These are types of stem cells that are found in a developing embryo, which is known as a blastocyst in scientific terms. Only a fertilized egg that has undergone the process of cell division can form the hollow ball of cells essential for this research. The total number of cells that exist in one blastocyst range between 70 to 100. The structure is such that it consists of three parts; blastocoele which is located inside, the embryoblast or the Inner Cell Mass (ICM) which forms the embryo, and the trophoblast which ultimately forms the placenta. The embryoblast is used for the research. The egg needs to be fertilized through the process of in-vitro fertilization.
These stem cells have many properties that allow them to develop into different types of body cells through the process or self-replication and differentiation. This self-renewing ability allows the possibility of being able to use the cells to treat several diseases and for healing.
Embryonic stem cells were first discovered by Gail Martin, Matthew Kaufman, and Martin Evans. They are what is known as pluripotent which allows them the capability to differentiate. The process by which a less-specialized cell can be transformed into a cell that is more specialized in nature is known in biological terms as differentiation. Due to this capability, embryonic stem cells are able to differentiate into all three germ layers of the body which are the ectoderm, mesoderm and the endoderm. This translates into an ability to transform into 220 different cell types. As mentioned earlier, these cells also possess the capability of self propagation. These two abilities increases their usefulness. Research suggests that they can be used for medical and scientific purposes. In 1998, James Thomson first developed the embryonic stem cell line which is an important part of the research. In order to develop a stem cell line the embryoblast has to be grown in a culture medium for almost six months. Those cells that retain the ability of pluripotency after repeated propagation are known as embryonic cell line and these are tested to ensure that they have the ability to self propagate.
Research has led scientists to believe that these cells can be used in the production of regenerative medicine and for the purpose of tissue replacement due to their ability to self-renew. Also since they are pluripotent in nature, it is possible that sufficient research of embryonic stem cells will lead to discovery of treatment for genetic diseases, Parkinson's, cancer, and other such diseases.
Controversy Over Research
"While we're all hopeful about the potential of this research, no one can be certain that the science will live up to the hope it has generated." - George Bush, August 2001
This study has been hounded by controversy since it was first put forward. The main reason for controversy in stem cell research is the fact that when these cells are removed or isolated from the blastocysts, it results in the death of the embryo it has been derived from. According to those who are pro-life, this is a destruction of human life as the embryo is the first stage after fertilization of an ovum and a spermatozoon. Thus, according to pro-lifers, destroying an embryo for research translates into murder of a human being, punishable as homicide. People who are pro-research though, maintain that a human embryo is not a person. Sure it can develop into a human being but without the necessary organs it cannot be classified as a human being. As a result of this constant debate, treatment of any disease does not use embryonic stem cells. Research involving adult stem cells is not as controversial in comparison, as the isolation of stem cells does not affect adult individuals.
This can be extremely helpful in several forms of research and treatment of various diseases but with the constant debate surrounding the study, practical application may not occur anytime in the near future. Most scientists support this research but with the politicization of the study and large-scale media exposure it has received, the debate continues.