Stem cells have the ability to transform into different types of cells and to self-renew, meaning they can divide and create new stem cells. These features make them widely used in regenerative medicine and the treatment of many diseases.
Types and sources of stem cells
Stem cells occur in various parts of the body, both in the embryonic development phase and in the adult body. Depending on the place of occurrence and type, they differ in their ability to differentiate into other cells. Here are the main sources of stem cells:
- Embryonic stem cells
- Embryos: these cells are found in the early stages of an organism’s development, specifically in blastocysts, structures that form a few days after fertilization. They are pluripotent, meaning they have the ability to develop into any type of cell in the body.
- Adult (somatic) stem cells
- Bone marrow: the marrow is a rich source of hematopoietic stem cells, which are responsible for producing all types of blood cells. They are widely used in the treatment of blood cancers such as leukemia.
- Peripheral blood: although in smaller quantities than in the bone marrow, stem cells can also be found in the blood. Special mobilization procedures are often used to isolate them to increase their numbers in the blood.
- Adipose tissue: stem cells, called mesenchymal stem cells, can be isolated from adipose tissue. They have the potential to transform into bone, cartilage, muscle and fat cells.
- Skin: the skin layers contain stem cells capable of regenerating skin tissue. They are crucial for wound healing and epidermal renewal.
- Brain: the brain contains neural stem cells that can differentiate into neurons and other cells that support the nervous system. In adults, they have a limited ability to regenerate, but are mainly active in the hippocampus and olfactory brain.
- Liver: the liver contains stem cells that play a role in regenerating damaged liver tissue. The liver regeneration process is possible thanks to the activity of these cells.
- Stem cells from cord blood and placenta
- Cord blood: rich in stem cells, it is a valuable source of hematopoietic stem cells. They can be collected during childbirth and stored for future use in treating blood diseases.
- Placenta: both hematopoietic and mesenchymal stem cells can be obtained from the placenta. Due to their ease of collection and high differentiation efficiency, the placenta is currently being explored as an alternative source of cells for regenerative therapies.
- Induced pluripotent stem (iPS) cells
- Somatic cells reprogrammed in the lab: iPS cells are created in the lab from mature adult cells, such as skin cells. By introducing the appropriate genes, these cells are reprogrammed to acquire the properties of embryonic stem cells, i.e. the ability to differentiate into any cell type.
Each of these types of stem cells has different therapeutic potential and specific applications, making them a key element in the development of regenerative medicine.
Functions and actions of stem cells
- Tissue regeneration: stem cells can replace damaged cells and rebuild damaged tissues. For example, they are used to treat injuries to the bone marrow, skin, and heart.
- Differentiation: they can transform into different cell types, allowing them to be used to create new cells for transplantation, such as nerve cells to treat neurodegenerative diseases.
- Treatment of genetic diseases: genetically modified stem cells can be introduced to correct genetic mutations and treat inherited diseases, such as cystic fibrosis or sickle cell anemia.
- Disease modeling: stem cells can be used to study disease mechanisms and test drugs, allowing for a better understanding and development of therapies for various conditions.
Applications in medicine
Stem cells have a wide range of applications in medicine, especially in treating diseases that are difficult to treat by other methods. In many cases, stem cell therapy offers unique opportunities to regenerate damaged tissues and restore functions lost due to disease or injury. Here are the main applications of stem cells in medicine:
- Bone marrow transplants and blood cancer therapy
Stem cells from bone marrow (mainly hematopoietic stem cells) are widely used to treat blood cancers such as leukemia, lymphomas, and myeloma. During the therapy, healthy stem cells are transplanted into the patient, which rebuild the hematopoietic system after chemotherapy or radiotherapy.
- Heart regeneration after a heart attack
Stem cells can be used to regenerate heart muscle after a heart attack. A heart attack causes permanent damage to the heart, but stem cells can potentially differentiate into heart muscle cells and rebuild the damaged tissue, restoring the heart to full function.
- Treatment of spinal cord injuries and neurodegenerative diseases
In the case of spinal cord injuries, stem cells can help rebuild neural connections and restore motor function. Stem cell therapy is also being studied in the context of neurodegenerative diseases such as Parkinson’s, Alzheimer’s and multiple sclerosis, to rebuild neurons and protect them from further damage.
- Skin regeneration after burns
Stem cells are used to treat extensive skin burns, allowing tissue to rebuild and speeding up wound healing. They can be used to create artificial skin or support the body’s natural regenerative processes.
- Treatment of genetic diseases
Reprogrammed stem cells can be genetically modified to correct genetic mutations. They are introduced into the patient’s body to prevent the development of genetic diseases such as cystic fibrosis, sickle cell anemia, and other inherited conditions.
- Cartilage and bone regeneration
Stem cells have applications in orthopedics, especially in treating joint injuries and degenerative diseases such as arthritis. They can regenerate cartilage tissue and help rebuild damaged bones, reducing pain and restoring joint function.
- Drug research and disease modeling
Stem cells can grow specific tissues that can be used to test new drugs. They can also be programmed in the lab to mimic diseases, allowing scientists to study their mechanisms and test potential therapies.
- Treating liver and kidney diseases
Stem cells can help regenerate damaged liver and kidney tissue, which is useful in cases of cirrhosis, liver failure, or kidney disease. They work by replacing damaged cells and supporting organ function.