Embryonic stem cells have generated an enormous amount of ethical controversy and discussion, primarily because of their source. As the name implies, embryonic stem cells are derived from embryos. As with all stem cells, embryonic stem cells are unspecialised cells that have the ability to:
- Self-renew for long periods of time
- Differentiate into specialised cells with specific functions
Embryonic stem cells have perhaps the greatest therapeutic potential because they are able to differentiate into all derivatives of the main germ layers, including over 220 types of cells in the human adult body.
The embryonic stem cells are usually derived from in vitro fertilisation, where the eggs have been fertilised in vitro (not in a woman’s body) and donated for research with donor consent. The embryos are generally utilised when they are approximately four or five days old and constitute a tiny ball of cells known as a blastocyst. Pluripotent embryonic stem cells are derived from the blastocyst. Embryonic stem cells can, however, be either totipotent or pluripotent cells. Those cells that are totipotent include the fertilised egg itself as well as the cells produced during the very early divisions. These totipotent embryonic stem cells have the ability to become any cell in the human body. Pluripotent stem cells, on the other hand, can become any type of cell in the body except those needed to develop a foetus.
Isolating and Growing Embryonic Stem Cells
Isolating and growing embryonic stem cells is key to harnessing their power to treat disease. If scientists are able to guide the differentiation of embryonic stem cells into different cell types, they can then replace diseased and dysfunctional cells. Some of the many diseases that could be treated by transplanting cells harvested from human embryos are:
- Cardiovascular diseases
- Parkinson’s disease
- Spinal injuries
Benefits of Embryonic Stem Cells
Embryonic stem cells have specific properties that make them particularly useful for cell-based therapies. They are obtained from early blastocysts, which means that they are at an early stage whereby they can develop into one of the more than 220 cell types in an adult. As scientists continue to research new techniques that will effectively coax embryonic stem cells to differentiate into specialised cells such as heart, muscle, or nerve, they will be able to treat a vast number of diseases. The ability of embryonic stem cells to proliferate indefinitely means that they can be produced in huge numbers to replace the many damaged cells that are present in a diseased adult.
Research on embryonic stem cells can also improve the safety of drugs. By testing drugs on embryonic stem cell lines, scientists can gauge their safety before testing them further in laboratory animals and human subjects. Also beneficial would be the knowledge of precisely how embryonic stem cells differentiate and proliferate. Many serious medical conditions such as cancer and birth defects result from dysfunctional cell replication and specialisation. If researchers can learn exactly what happens during normal healthy cell development, they can better understand what happens to lead to disease.
Concerns About Embryonic Stem Cell Use
Although embryonic stem cells have an enormous capacity for treating disease because of their potentially unlimited ability to self-renew, there are still concerns regarding their use. The ethical controversy around embryonic stem cells is mainly based on the destruction of an embryo for cells because this embryo could potentially become a viable organism. There are also concerns regarding immune rejection, where a patient’s immune system rejects the healthy embryonic stem cells.
Embryonic stem cells are certainly a promising discovery, but their use will likely not become consistent and approved until procedures for isolating and growing them are proven and defined. A lack of widespread public acceptance also clouds the therapeutic use of embryonic stem cells but hopefully, the concerns and challenges can be overcome in the future so that those suffering from serious diseases can benefit from embryonic stem cells.