Stem cell research has become very popular recently because they can help us understand how diseases occur, generate healthy cells to replace cells affected by disease, and also test new drugs for safety. Stem cells could become vital to the future of medicine.
Stem cells are unspecialised cells that have the ability to develop into many different types of cells. There are two type of stem cells in humans: embryonic stem cells and adult stem cells. Embryonic stem cells come from embryos (blastocysts) that are 3 to 5 days old and can differentiate to form all of the specialised cells in our body. It is often the focus of stem cell research. An adult stem cell is an undifferentiated cell that resides among differentiated cells in a tissue or organ. They have the ability to renew themselves and differentiate into special types, where their primary role is to maintain and repair the tissue in which they reside in. The bone marrow is a very good source of adult stem cells, even though they are often few in number.
In 1998, two scientists managed to culture human embryonic stem cells, with the hope that they can be encouraged to grow into any type of cell needed in the body, in what was a breakthrough for stem cell research.
In 2010, the first trials testing the safety of injecting nerve cells grown from the embryonic stem cells into the spinal cords of paralysed human patients were carried out. Scientists hoped that the stem cells could help people who have been paralysed to walk again.
In 2014, doctors transplanted embryonic stem cells into the yes of people going blind as a result of macular degeneration – an eye condition where cells in the middle of the retina die or are damaged, making it difficult to see fine details clearly. All of the patients found that they could see better. Larger trials are now taking place.
However, there are concerns about stem cell research, with some people believing it is unethical to kill embryos for their cells, potentially killing a life. Others think that, as the embryo cannot give permission, using embryonic stem cells is a violation of its human rights.
Additionally, there is a risk that adult stem cells might be infected with viruses or pathogens and could transfer the infections to patients. It might also trigger an immune response, or it could be rejected by the human body.
The future of stem cell research may lie with therapeutic cloning, an area that has a lot of potential, and involves using cells from an adult to produce a cloned early embryo of themselves. This would provide a source of perfectly matched embryonic stem cells. In theory, these could be used for medical treatments, such as growing new organs for the original donor. The new organs would not be rejected by the body because they have been made from the body’s own cells and have the same genes.
After years of relatively slow progress, hopes are high again that stem cells will change the future of medicine.
