Q: What are stem cells?
A: They are special ‘master’ cells that can turn into any type of cell the body needs.
There are two types: embryonic stem cells, which can convert into any cell, and adult stem cells, which turn into different cell types based on their tissue of origin. The latter have been found in the bone marrow, brain, skin, teeth, gut and other organs.
They may remain dormant for years, dividing and creating new cells only when they are activated by injury or disease.
Q: How do they work?
A: Transplanted stem cells can help repair or regenerate damaged tissue.
The exact form of treatment depends on the condition. With MS, for instance, faulty immune cells attacking nerve coverings must first be destroyed with chemotherapy.
A new immune system is then built using stem cells from bone marrow.
Q: What can they treat?
A: Scientists are looking at treatments for everything from age-related sight loss to diabetes and spinal injuries.
In the UK, stem cells have so far shown beneficial results in treating blood cancers such as leukaemia, heart failure and MS, all as part of clinical trials.