The realization of the promise of stem Cell Therapy is undoubtedly one of most exciting research goals in the scientific community today. The potential for cures of many diseases have motivated and inspired scientists all over the world to study and understand how to capture and manifest this power into a new generation of 21st century therapeutics. In order to capture this power, you need to begin with its most crucial part — the source of the stem cells.
I am sure you have heard about the most controversial source, human embryonic stem cells. This type of cell can differentiate into any cell type, thus making it a valuable source of therapeutic stem cells. There are also less controversial sources such as stem cells from adipose tissue, induced pluripotent stem cells (iPSCs) and cells from the umbilical cord. I find one source particularly interesting; especially for those who missed the chance of collecting stem cells from cord blood — your teeth.
According to the website of the National Dental Pulp Laboratory, stem cells (specifically mesenchymal stem cells) that are suitable for tissue engineering were discovered from dental pulp in the year 2000 by an NIH dental researcher named Dr. Songtao Shi. The NIH officially announced this discovery in 2003. For some of us, we may have missed our chance (except for the adipose tissue sourcing, which I for one would not mind donating for I seem to have an abundance of it). Dental pulp stem cells are supposed to be harvested when children lose their baby teeth. Hence, these stem cells are called SHED or stem cells from human exfoliated deciduous teeth. The National Dental Pulp Laboratory states “the teeth that contain the highest quantity and quality of stem cells will be those that maintain a blood supply until they are harvested.”
A recent article by Luciano Casagrande, et. al (“Dental pulp stem cells in regenerative dentistry.” Odontology. 2011, 99:1-7) describes the dental pulp as a rich source of mesenchymal stem cells for regenerative applications. They can be differentiated to form osteoblasts (bone), chondrocytes (cartilage), cardiomyocytes (heart), neuronal (brain and spinal cord) and adipocytes (fat cells). They also found in their studies that stem cells from dental pulp also have the potential to differentiate into blood vessels. According to Casagrande’s group, this is a significant finding in that one of the major challenges for stem-based regeneration is the availability of an efficient blood vessel network that can facilitate tissue repair.
However, this is just one aspect of the intricate design of tissue generation. Many questions still remain about, and we have yet to completely understand, how stem Cell Therapy can mimic the highly complex phenomenon of an embryo developing into a fully functional and independent living system. I agree with Casagrande’s group when they call on scientists to fully understand the complexities of the cellular events, signals and interactions that are necessary to achieve the desired tissue regeneration. And whether it comes from the embryo itself or any other sources after birth, we need to find the answers. They are the key to the realization of the power of stem Cell Therapy.