Author: Karen Liu
Editor: Anand Soma
Artist: Karen Liu
You may have heard about stem cells in biology, or perhaps they were used to treat a loved one, but what exactly are stem cells, and why are they a subject of such contentious debate?
Stem cells are essential in dealing with injury and disease. Being the raw materials of the body, they can specialize and develop into other types of cells ranging from muscle cells to nerve cells. Therefore, they can be useful to grow new cells in a laboratory to replace damaged organs or tissues, connect parts of organs, research genetic defects in cells, research how diseases occur and test new drugs for safety and effectiveness.
There are two main types of stem cells: embryonic stem cells and adult stem cells. Embryonic stem cells come from embryos around 3-5 days old and are harvested in vitro-fertilization. Embryonic stem cells are also pluripotent, which means they can develop into more than one type of cell. Adult stem cells come from the body organs and tissues. They can be found in anyone, including infants, so the name is slightly misleading since they do not only apply to adults! Adult stem cells are used by the body to heal damaged tissue. They’re most commonly found in skin and bone marrow. However, there are small amounts of these stem cells and they can only generate certain types of stem cells. For instance, a stem cell from the liver can only create more liver cells whereas embryonic stem cells can develop into anything.
There has been a lot of controversy around stem cells, however, harvesting embryonic stem cells raise many ethical concerns. During the process of harvesting embryonic stem cells, the embryo is destroyed, raising questions about whether this process is morally wrong. On one hand, some people argue that an embryo is a living human being, and should not be killed for research purposes. On the other hand, other people claim that an embryo is not yet a human and besides, the eggs fertilized in vitro-fertilization were never implanted in a woman's uterus and would most likely be discarded anyway so with consent, it wouldn’t matter. However, recently, there has been a rise of induced pluripotent stem cells or (iPSC) where scientists discovered how to transform adult stem cells into embryonic stem cells, eliminating the question of ethics. The path to perfecting this is still rocky, but it provides a promising future.
Citations:
Cafasso, Jacquelyn. “Stem Cell Research: Uses, Types & Examples.” Healthline, Healthline
Media, 9 July 2017,
www.healthline.com/health/stem-cell-research.
Stanford Medicine. “What Are Stem Cells?” Stanford Children's Health - Lucile Packard
Children's Hospital Stanford,
www.stanfordchildrens.org/en/topic/default?id=what-are-stem-cells-160-38.
“Stem Cells: What They Are and What They Do.” Mayo Clinic, Mayo Foundation for Medical
Education and Research, 8 June 2019,
www.mayoclinic.org/tests-procedures/bone-marrow-transplant/in-depth/stem-cells/art
20048117.