Stem cell research is one of the most fascinating areas of contemporary biology, but, as with many expanding fields of scientific inquiry, research on stem cells raises scientific questions as rapidly as it generates new discoveries. Some stem cells, such as the adult bone marrow or peripheral blood stem cells, have been used in clinical therapies for over 40 years. Other therapies utilizing stem cells include skin replacement from adult stem cells harvested from hair follicles that have been grown in culture to produce skin grafts.
There were side effects accompanying these studies and further investigation is warranted. Although there is much research to be conducted in the future, these studies give us hope for the future of therapeutics with stem cell research.
In the early s, scientists began studying embryonic stem cells, first in mice. But because mouse embryos develop very differently than human embryos, researchers soon sought a way to isolate human embryonic stem cells. In , a team lead by James Thomson at the University of Wisconsin was the first to successfully harvest stem cells from human embryos donated by fertility clinics.
Since then, scientists have developed some stem cell lines using private and public funds. Embryonic stem cells are harvested in two ways: from existing human embryos and from embryos that have been created using a cloning process known as somatic cell nuclear transfer SCNT. In both cases, the embryo is ultimately destroyed, which opponents of embryonic stem cell research argue is immoral.
The egg is then stimulated to begin subdividing, eventually growing into an embryo with stem cells that can be harvested. Many scientists consider SCNT very promising because it creates an embryo with stem cells that have the same DNA code as the person who donated the cell nucleus.
In , Thomson and his team at the University of Wisconsin, along with scientists in Tokyo, created what appear to be pluripotent cells from adult human skin cells rather than from embryonic cells. The new technique coaxes skin cells to revert to an embryonic stem cell state by inserting a tiny DNA-containing virus. Stem cell research is helping scientists understand how an organism develops from a single cell and how healthy cells could be useful in replacing cells that are not working correctly in people and animals.
Researchers are now studying stem cells to see if they could help treat a variety of conditions that impact different body systems and parts. This article looks at types of stem cells, their potential uses, and some ethical concerns about their use. The human body requires many different types of cells to function, but it does not produce every cell type fully formed and ready to use. Scientists extract embryonic stem cells from unused embryos left over from in vitro fertilization procedures.
They do this by taking the cells from the embryos at the blastocyst stage , which is the phase in development before the embryo implants in the uterus. These cells are undifferentiated cells that divide and replicate. However, they are also able to differentiate into specific types of cells. There are two main types of adult stem cells: those in developed bodily tissues and induced pluripotent stem iPS cells.
Developed bodily tissues — such as organs, muscles, skin, and bone — include some stem cells. These cells can typically become differentiated cells based on where they exist.
For example, a brain stem cell can only become a brain cell. On the other hand, scientists manipulate iPS cells to make them behave more like embryonic stem cells for use in regenerative medicine. After collecting the stem cells, scientists usually store them in liquid nitrogen for future use. However, researchers have not yet been able to turn these cells into any kind of bodily cell. The list of conditions that stem cell therapy could help treat may be endless. Doctors may also be able to use stem cells to treat injuries in the spinal cord or other parts of the body.
In some tissues, stem cells play an essential role in regeneration, as they can divide easily to replace dead cells. Scientists believe that knowing how stem cells work can help treat damaged tissue. This could cause the heart tissue to renew itself. One study suggested that people with heart failure showed some improvement 2 years after a single-dose administration of stem cell therapy.
However, the effect of stem cell therapy on the heart is still not fully clear, and research is still ongoing. Another investigation suggested that stem cell therapies could be the basis of personalized diabetes treatment. Editorial 19 August Correspondence 20 July Diabetes therapeutic approaches continue to expand and to be refined. As the field moves toward more intensive insulin- and cell-based therapies, care must be taken to mimic healthy physiological insulin dynamics and avoid hyperinsulinemia, with its deleterious downstream complications.
Editorial 07 July Advanced search. Skip to main content Thank you for visiting nature. Atom RSS Feed Stem-cell research Definition Stem-cell research is the area of research that studies the properties of stem cells and their potential use in medicine.
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