Mesenchymal (stromal) stem cells give rise to a variety of cell types, including bone cells (osteocytes), cartilage cells (chondrocytes), fat cells (adipocytes), pancreatic islet cells and connective tissue cells such as those found in tendons.
Mesenchymal stem cells can be found in umbilical cord blood, fat, muscle and the pulp of baby teeth. They are referred to as multipotent cells because they can develop into multiple tissues, but they do not have the capacity to reconstitute an entire organ.
An extremely rich source of mesenchymal stem cells is the developing tooth bud of the mandibular (lower) third molar, or wisdom tooth. While considered multipotent, these stem cells may prove to be pluripotent, capable of generating all tissue types. The stem cells found in developing third molars eventually form enamel, dentin, blood vessels, dental pulp, nervous tissue and a minimum of 29 different unique tissues and organs. Because of extreme ease in collection at 8–10 years of age, they will probably constitute a major source for personal banking, research and multiple therapies.
Adipose (fat) tissue is one of the richest sources of mesenchymal stem cells. There are 500 times more mesenchymal stem cells in 1 gram of fat than there are in 1 gram of bone marrow.
Mesenchymal stem cells are of intense therapeutic interest because they represent a population of cells with the potential to treat a wide range of acute and degenerative diseases.
Because they give rise to so many tissue types, mesenchymal stem cells add significantly to the field of regenerative repair. In addition to assisting the function of bone marrow and adipose (fat) derived stem cells, recent advances include the use of mesenchymal stem cells to:
- Regenerate damaged cartilage
- Regeneration of the meniscus (knee)
- Regeneration of damaged tendons
- Repair of bone fractures