Definition of an Adult Stem Cell
The first stem cells were identified in embryos. These are called embryonic stem cells. There are also large numbers of stem cells in the umbilical cord. These are usually called cord blood stem cells. Stem cells that come from adult tissues like bone marrow or fat are called adult stem cells. Embryonic stem cells raise significant ethical concerns and their use it highly restricted in the United States. Cord blood stem cells have very limited availability. Adult stem cells are an area of intense interest and widespread availability. The two tissues most commonly used to obtain or harvest adult stem cells are bone marrow and fat.
Fat adult stem cells are also known as adipose-derived adult stem cells. Adult stem cells from fat are easier to obtain and exist in larger numbers than bone marrow adult stem cells. Therefore, there is an increasing interest in fat (adipose) derived adult stem cells.
All stem cells share two important characteristics:
- The ability to multiply. This means in theory they can make an infinite number of copies.
- Stem cells can become other types of cells. For example, stem cells from fat can become skin, muscle, or bone stem cells. They can then produce infinite numbers of the new type of cells.
It is these abilities that make adult stem cells so important in the future of medicine. We are starting to understand how to use adult stem cells to bring natural healing to diseases and injuries. Current investigations are researching the use of adult stem cells to repair many diseases and injuries that previously could not be repaired.