Embryonic Stem Cells vs. Umbilical Cord Stem Cells

Stem cells are cells that have the remarkable potential to develop into many different cell types in the body. There are three classes of stem cells: totipotent, multipotent, and pluripotent. A fertilized egg is considered totipotent, meaning that its potential is total; it gives rise to all the different types of cells in the body. Multipotent stem cells (Umbilical Cord stem cells) that can give rise to a small number of different cell types. Pluripotent stem cells (Embryonic stem cells) can give rise to any type of cell in the body except those needed to develop a fetus. Pluripotent stem cells (Embryonic stem cells) are isolated from human embryos that are a few days old. Cells from these embryos can be used to create pluripotent stem cell "lines."

These are cell cultures that can be grown indefinitely in the laboratory. Pluripotent stem cell lines have also been developed from fetal tissue obtained from fetal tissue (older than 8 weeks of development). Pluripotent stem cells, while having great therapeutic potential, face formidable technical challenges. First, scientists must learn how to control their development into all the different types of cells in the body. Second, the cells now available for research are likely to be rejected by a patient's immune system. Finally, the idea of using stem cells from human embryos or human fetal tissue troubles many people on ethical grounds.

Conversely, multipotent stem cells (Umbilical Cord stem cells), such as blood-forming stem cells in bone marrow (called hematopoietic stem cells, or HSCs) are currently the only type of stem cell commonly being used to treat human diseases. Doctors have been transferring HSCs in bone marrow transplants for years. More advanced techniques of collecting, or "harvesting", HSCs are now used in order to treat leukemia, lymphoma and several inherited blood disorders. The clinical potential of Umbilical Cord stem cells has also been demonstrated in the treatment of other human diseases.

However, these newer uses have involved studies with a very limited number of patients. Until recently, there was little evidence that multipotent, Umbilical Cord stem cells could change course and provide the flexibility that researchers need in order to address all the medical diseases and disorders they would like to. New findings in animals, however, suggest that even after a stem cell has begun to specialize, it may be more flexible than previously thought. There are currently several limitations to using Umbilical Cord stem cells, too. Although many different kinds of multipotent stem cells have been identified, Umbilical Cord stem cells that could give rise to all cell and tissue types have not yet been found. Thus, although human Embryonic stem cells are thought to have much greater developmental potential, umbilical cord blood stem cells have already been used successfully in the treatment of many diseases and disorders, and without the ethical concerns surrounding Embryonic stem cell use.