Stem cells are undifferentiated cells that can divide repeatedly and differentiate into specialised cells. Stem cell therapy uses them to replace cells that have been damaged or lost through disease or injury.Stem cells for therapy can come from three main sources:
• embryonic stem cells, which are pluripotent
• adult stem cells, such as those in bone marrow, which are multipotent (they form only a limited range of cell types, such as blood cells)
• induced pluripotent stem cells, made by reprogramming adult body cells.The best established stem cell therapy is the bone marrow transplant. It has been used for decades to treat leukaemia and other blood disorders: the patient's faulty bone marrow is destroyed and replaced with stem cells that go on to make all the types of blood cell.For most other therapies the general steps are:
1. obtain stem cells and grow them in culture
2. stimulate them to differentiate into the required cell type by culturing them with specific growth factors
3. transplant the specialised cells into the damaged tissue, where they should integrate and work normally.A major issue is rejection. Cells from a donor carry different cell-surface antigens, so the patient's immune system may attack them, and the patient may need immunosuppressant drugs. Stem cells taken from the patient's own body, or made from their own cells, have matching antigens and are not rejected.
• embryonic stem cells, which are pluripotent
• adult stem cells, such as those in bone marrow, which are multipotent (they form only a limited range of cell types, such as blood cells)
• induced pluripotent stem cells, made by reprogramming adult body cells.The best established stem cell therapy is the bone marrow transplant. It has been used for decades to treat leukaemia and other blood disorders: the patient's faulty bone marrow is destroyed and replaced with stem cells that go on to make all the types of blood cell.For most other therapies the general steps are:
1. obtain stem cells and grow them in culture
2. stimulate them to differentiate into the required cell type by culturing them with specific growth factors
3. transplant the specialised cells into the damaged tissue, where they should integrate and work normally.A major issue is rejection. Cells from a donor carry different cell-surface antigens, so the patient's immune system may attack them, and the patient may need immunosuppressant drugs. Stem cells taken from the patient's own body, or made from their own cells, have matching antigens and are not rejected.