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What are Embryonic Stem Cells?

What are Embryonic Stem Cells?

Embryonic stem cells are pluripotent stem cells derived from the inner cell mass of a blastocyst, a pre-implantation embryo. They can be used to test drugs, model diseases, and as therapies that can be injected into the body. Embryonic stem cells are a type of stem cell: an undifferentiated cell which can become multiple types of cell and proliferate indefinitely. In this article we answer the questions what are embryonic stem cells and what are embryonic stem cells used for, and discuss research on embryonic stem cells, embryonic stem cell treatment, and embryonic stem cell controversy.

What are Embryonic Stem Cells? 

Embryonic stem cells are stem cells derived from the inner cell mass of a blastocyst. The blastocyst is a mass of 200-300 cells which begins to form about five days after fertilization. The blastocyst then implants itself in the wall of the uterus to grow in size and eventually become an embryo. Embryonic stem cells have an unlimited capacity for self-renewal, as well as the potential to differentiate into any somatic cell type within the body. 

What are Embryonic Stem Cells Used for?

Embryonic stem cells can be used to test drugs, model diseases, and as therapies that can be injected into the body. Their ability to grow and differentiate into different cell types allows them to potentially be used to repair various tissues and organs. In practice, however, embryonic stem cells are far less reliable and safe than mesenchymal stem cells. They can engender rejection and lead to tumor formation. 

Risks of Embryonic Stem Cells

There are many risks associated with embryonic stem cells. Embryonic stem cells are no longer used in most clinical trials due to their associated risks. Several clinical studies have shown that the injection of embryonic stem cells can lead to the formation of malignant tumors such as Teratocarcinoma. Research participants who receive a transplantation of embryonic stem cells may also be in danger of neurological complications if the stem cells migrate to the wrong parts of the brain. The injection of embryonic stem cells can also cause hemorrhaging and infection due to factors outside the patient's control such as brain anatomy or postoperative care. 

Embryonic stem cells have substantial hurdles to overcome before they can be safely and consistently used in human treatment. Unlike mesenchymal stem cells, embryonic stem cells can also be rejected by patients in two ways. The body’s immune system can attack the donor stem cells, or the body’s current stem cells can attack the donor cells. 

Research on Embryonic Stem Cells

Research on Embryonic stem cells began in 1981 when scientists first discovered how to culture stem cells from mouse embryos. In 1998, researchers first figured out how to harvest human embryonic stem cells. Three years later, President George W. Bush authorized the use of federal funds for research on a small batch of embryonic stem cell lines. Further development on embryonic stem cell research occurred in 2009 when biotechnology company Geron Corporation initiated a limited trial of embryonic stem cells to treat spinal cord injuries. In the years since, scientists have learnt how to turn embryonic stem cells into countless different cell types to repair tissue and organs within the body. 

Embryonic Stem Cells Controversy

The harvesting of embryonic stem cells has drawn controversy because it involves the destruction of human embryos. Embryonic stem cells are harvested days after fertilization by transferring the cell mass of the blastocyst into an environment suited for cell growth. Opponents of embryonic stem cell harvesting argue that it is unethical because it results in the destruction of human life for the purpose of research. 

Embryonic Stem Cells Treatment

Embryonic stem cells can be implanted, transplanted, or injected into a person to repair dysfunctional or diseased tissue. Before embryonic stem cell injection, the cells are developed into specific adult cell types, a process which takes about three days. This prepares the stem cells to most effectively repair diseased tissue. 

Summary

Embryonic stem cells are pluripotent stem cells derived from the inner mass of an early-stage embryo. They are a type of stem cell, unspecialized cells which do not yet have a specific function and can become any kind of cell in the body. Their ability to differentiate into various cell types and unlimited capacity for self-renewal would make them useful in repairing tissue and curing disease, if not for the risks associated with their use. Embryonic stem cell research has drawn controversy due to ethical concerns over human embryos.