What is it really
What are the types of stem cells
Why is it so relevant now
What are the successes of stem cell treatment
What are the problems with them
Ethical controversy
Answers to the main questions
What is it really
Every cell in our body has a function.
We think with neurons, we move with the help of myocytes, and red blood cells carry oxygen. But there are special cells - stem cells, which have no specialization.
They do nothing and just wait. And at the right moment, they begin to divide, and some of them turn into functional cells. The other part remains stem, in order to produce new specialized ones in the future.
What are the types of stem cells
There are two types of stem cells: embryonic and tissue.
Embryonic can turn into any other cells. It is from them that the embryo consists in the first 3-5 days of life. And if they are maintained in special conditions, they will divide almost indefinitely and remain unchanged.
Tissue cells are found in small numbers in the organs of an adult. They are needed to restore tissues after damage and can only transform into some particular type of cell. However, scientists have learned how to make analogues of embryonic tissue cells from tissue cells, from which different tissues can be grown. They are called pluripotent stem cells.
Why is it so relevant now
What if a new heart could be grown to replace a worn heart?
Or will doctors learn to repair organs right in the body without surgery? These are the breakthroughs that stem cell researchers are looking for. Scientists call it regenerative medicine.
It is believed that regenerative medicine can cope with incurable diseases such as:
strokes;
heart disease;
diabetes;
Parkinson's disease;
Alzheimer's disease;
amyotrophic lateral sclerosis;
cancer;
severe burns;
osteoarthritis and others.
But that is not all.
Even if regenerative medicine never becomes a reality, stem cells are already providing many benefits.
By watching them mature into cells in bones, nerves, and other organs, doctors can better understand how hereditary diseases develop.
Finally, pharmacists are testing new drugs on stem cells. To start testing a drug in humans, you must first make sure that it is safe. For this, tissues grown from stem cells are used. For example, you can grow nerve cells to test a new drug for a nerve disease. Such tests detect dangerous side effects or beneficial effects in advance.
What are the successes of stem cell treatment
Regenerative medicine is now in its infancy. There are a lot of research programs, but only a few technologies have been launched into “serial production”. However, even intermediate results seem impressive.
For example, in 2016, a team of scientists from Greece and the UK tried to restore muscle tissue after a heart attack. To do this, they transplanted stem cells of the heart muscle grown in the laboratory into the hearts of patients. As a result, the post-infarction scar decreased by 40%. Previously, doctors considered such injuries incurable. However, only 11 people participated in this study. This is not enough to draw firm conclusions.
Gradually, scientists improve technology. Here is an example. When transplanting tissues derived from stem cells, the immune system can attack the transplant, as it considers it to be something foreign. Therefore, doctors are working to create cells that do not cause an immune response. In 2020, researchers at the Karolinska Institute and St. Eric's Eye Hospital in Sweden discovered a way to improve the production of retinal cells from embryonic stem cells to treat blindness in the elderly. They change these cells so that they can hide from the immune system, which destroys foreign objects.
Another promising technology is the use of stem cells that are already in the body.
In one experiment, researchers at the University of Illinois injected damaged rat muscles with nanoparticles containing molecules that stimulate stem cell activity. As a result, muscles recovered faster and animals were able to walk further than with conventional treatment.
What are the problems with them
Despite outstanding advances in research, doctors actively use only one method of stem cell treatment - bone marrow tissue stem cell transplantation for blood cancers.
There are many obstacles that prevent a breakthrough in regenerative medicine. For example, unpredictability. Researchers need to be sure that stem cells will turn into the tissue they need. Doctors also need to learn how to regulate the growth and reproduction of stem cells so that they do not begin to divide uncontrollably, creating cancerous tumors.
As we have said, the immune system can attack embryonic stem cells, believing them to be foreign invaders.
In addition, existing technologies cause many side effects. Patients treated with stem cells for multiple sclerosis experienced lower platelet and white blood cell counts, infections, and toxic liver damage.
Finally, it is still a very expensive method. For example, in the multiple sclerosis treatment example mentioned, the procedure cost £40,000.
Ethical controversy
They arise from embryonic stem cells, which are extracted from embryos in the early stages of development. Some people disagree with using embryonic cells for medical research because it means destroying the fetus. The essence of the dispute is the same as between supporters and opponents of abortion.
The first argue that life begins at birth (or from the moment the embryo becomes a fetus). Others count the birth of a new life from conception, and consider the destruction of the embryo to be murder.
Many countries have banned the production and use of cells obtained by interrupting the development of a human embryo or fetus.
There are no disputes with tissue cells, since they are obtained from adults.
