Stem cell therapy is a relatively new field in modern medicine. Although it has attracted considerable attention because of its potential, its practical use remains limited. In the United States, only a small number of stem cell treatments have been authorized for patients. One example is the treatment of leukemia, a type of blood cancer, which is among the conditions for which the U.S. Food and Drug Administration has permitted hospitals to provide treatment.
For many people, these limitations are disappointing because stem cell therapy has demonstrated significant potential in other areas of medicine. It is considered a possible treatment approach for conditions such as Alzheimer’s disease, Parkinson’s disease, arthritis, and more complex disorders, including Autism Spectrum Disorder (ASD).
Research in this field is still continuing, and it is possible that stem cell therapy will become available for a wider range of conditions in the future. To understand why this area of medicine is relatively new and why its use remains limited, it is helpful to first understand what stem cells are.
The Blank Slate
For many years, stem cells existed primarily as a medical concept rather than a proven scientific reality. Nevertheless, scientists understood that cells with unique capabilities had to exist because human development would otherwise be impossible.
Under normal circumstances, most cells in the human body produce new cells of the same type. For example, skin cells generate new skin cells to replace those lost or damaged through injuries. Hair cells likewise produce new hair cells when hair is lost.
A skin cell cannot normally develop into a brain cell. Some types of cells, including heart cells, also have very limited ability to reproduce, which means that damage to the heart can be permanent.
Human development presents a different situation. During pregnancy, a baby develops from a fertilized egg even though the specialized cells that make up the skin, bones, lungs, blood, and other organs do not yet exist. The fertilized egg eventually produces cells that develop into the different tissues and organs of the body.
These unique cells are known as stem cells, although medical science was unable to identify them for many years.
The Breakthrough
A major step forward came in 1981, when researchers isolated stem cells during experiments involving mice.
Martin Evans, a researcher at Cambridge University in the United Kingdom, became the first scientist to identify embryonic stem cells in mice. He subsequently isolated the cells, modified them, and transplanted them into female mice.
The experiment was successful. The genetically modified stem cells developed in the female mice and resulted in offspring that had been scientifically altered. This demonstrated that stem cells could not only be identified but also modified and used, at least in laboratory mice.
The Human Equation
It took considerably longer to achieve a similar breakthrough with human cells. In 1998, researchers succeeded in identifying, isolating, modifying, and growing specifically cultured human stem cells.
Two research teams achieved this independently. James Thomson at the University of Wisconsin and John Gearhart at Johns Hopkins University in Baltimore both successfully isolated and grew human stem cells.
As knowledge of stem cells increased, the research also became the subject of public debate. The initial work involved embryonic cells that were no longer needed for in vitro fertilization (IVF). Obtaining these cells resulted in the destruction of the embryo, which became an important source of controversy.
The Barriers Drop
In 2001, the President of the United States, George W. Bush, introduced restrictions on stem cell research because of ethical and religious concerns.
Stem cell lines that had already been cultured and developed through earlier experiments could continue to be used, but researchers were not permitted to obtain new sources for cultivation.
This created a significant obstacle for scientists because the available material for research became more limited. As a result, progress in the field slowed.
More Discoveries
Despite these restrictions, the potential of stem cell research and therapy continued to drive significant developments in medical science.
In 2007, researchers successfully reprogrammed stem cells. Two years later, in 2009, President Barack Obama removed the restrictions on stem cell research.
Research into the use of stem cells for spinal injuries was conducted in 2010, while research into treating blindness began in 2012.
The Current State
In the United States, stem cell treatment remains largely associated with research, with leukemia being one of the treatments available to the public. Other countries, including Georgia, offer stem cell therapy.
This type of treatment requires a supply of stem cells that is biologically compatible with the patient.
Stem cells used in this approach may come from the mother’s womb after a child is born. When such a source is not available, stem cells may instead come from a close genetic relative, such as a sibling born to the same mother at a later time.
Stem cells can also be obtained from bone marrow. However, bone marrow stem cells are not pluripotent like embryonic stem cells and are therefore less versatile.
