Stem cells are cells that can develop in different ways to form all the organs of the body, from bones, kidneys and liver to blood and brain. Special types of stem cells have the ability to block immune responses. Therefore, stem cells could be very useful as treatments for diseases where organs are damaged or the immune system is overactive. Certain types of stem cells are already used in therapy, such as hematopoietic (blood) stem cells for bone marrow cancer. The use of other types of stem cells is currently being investigated in the laboratory and in experimental therapies. Researchers are trying to figure out the best way to deliver stem cells to patients, where the cells go in the body and how long they survive in the patient.
The most established and widely used stem cell therapy is blood stem cell transplantation, which is used to treat diseases and conditions of the blood and immune system or to restore the blood system after treatment for specific cancers. Additionally, skin stem cells have been used since the 1980s to grow skin grafts for patients with extensive and severe burns on their bodies.
Embryonic stem cells may well become an important therapy for repairing organs. In the lab, researchers can grow embryonic stem cells into any desired cell type or into small, organ-like 3D clusters of cells called organoids. Cells or organoids can be implanted in organs injured by accident or disease, where they help repair the damage. The safety of such treatments remains questionable, but some preliminary tests have been done in humans to repair damaged eyes using cells derived from embryonic stem cells.
The disadvantage of embryonic stem cells is that they must be harvested from embryos. These embryos come from in vitro fertilization, a technique used to fertilize egg cells with sperm outside the body. program. In vitro fertilization is a technique in which eggs are fertilized with sperm outside the body. After a few days, the fertilized eggs develop into tiny embryos, which are then placed back into the mother's body. This is sometimes done for those who cannot conceive easily. Unplaced embryos produced by in vitro fertilization are sometimes used to isolate embryonic stem cells.
In addition to embryonic stem cells, there are other types of stem cells that are present in both children and adults. The only type of stem cell currently used widely in hospitals as a treatment is hematopoietic (or blood) stem cells. People with cancer of the bone marrow (leukemia) receive chemotherapy to kill all cancer cells. All of the patient's vital blood stem cells will also be killed as a result of the treatment. To replace hematopoietic stem cells after chemotherapy, some stem cells are collected from the patient's bone marrow before chemotherapy and stored in a refrigerator. After treatment, the hematopoietic stem cells are returned to the patient. These cells then divide until enough stem cells emerge, which then form red and white blood cells and build a functional immune system.
Mesenchymal stem cells are found in any organ, including bones, adipose tissue, lungs, heart and brain. The function of mesenchymal stem cells is first to repair the body by developing into cells that form connective tissue, fat tissue and bone tissue. Second, mesenchymal stem cells help other cells in the body. They do this by producing compounds that help other cells survive and divide. A third function of mesenchymal stem cells is that they can prevent immune responses. In the case of an immune response against infection, mesenchymal stem cells ensure that the immune response does not get out of hand. Mesenchymal stem cells are being tested as experimental treatments for a variety of diseases. The way in which mesenchymal stem cells are given to a patient depends on the disease they are being used to treat. When mesenchymal stem cells are used to repair broken bones, the cells are placed on structures that support the cells.
There is a lot of research into how stem cells can be used to treat disease. It is expected that in the future, stem cell therapies will be developed for many types of diseases for which there are currently no effective treatments.