| Stem cells are rare, undifferentiated cells (i.e., cells without a defined, specified function) within the human body that have the potential to replace and renew differentiated cells. Stem cells can also produce additional stem cells. In some cases, stem cells generate an intermediate cell type before they achieve their fully differentiated state. The intermediate cells, called progenitor cells, are partially differentiated cells that then divide and become fully differentiated cells.
Human adult stem cells can be derived from a variety of sources, including bone marrow, blood from an umbilical cord removed after childbirth and blood circulating throughout the body, which is known as peripheral blood. Bone marrow can be obtained from a patient or from a suitable, appropriately matched donor. Blood from umbilical cords, referred to as cord blood, is stored in cord blood banks throughout the world. Stem cells can also be derived from the tissue of human embryos, but we do not use embryonic stem cells in our product candidates.
There are many types of adult stem cells and progenitor cells found in the human body, including:
- Hematopoietic stem cells generate all of the blood and immune system cells in the body, including red blood cells, platelets and neutrophils.
- Mesenchymal stem cells differentiate into many cell types, including bone, cartilage, fat, muscle, tendon and other connective tissues.
- Neural stem cells are capable of differentiating into neurons and cells that support nerve tissue.
- Endothelial progenitor cells differentiate into the cells that line the blood vessels.
Many researchers believe that stem cells hold significant promise in the treatment of a wide variety of diseases. Researchers have reported progress in the development of new therapies utilizing stem cells for the treatment of cancer as well as neurological, immunological, genetic, cardiac, pancreatic, liver and degenerative diseases. In seeking to apply stem cell therapies to these diseases, researchers have explored both autologous and allogeneic stem cell therapies. Autologous therapies use stem cells derived from the patient receiving the therapy, while allogeneic therapies use stem cells derived from a separate donor.
Stem cells represent a very small fraction, typically less than 1%, of the cells in a cord blood or bone marrow source. As a result, we believe that the proper selection of the stem cells that are expected to have the greatest therapeutic effect, and the isolation of those cells from the other cells in the cord blood or bone marrow source, is critical to the successful development of any regenerative therapy based on stem cells.
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