Curing disease with stem cells
What are stem cells?
The vast majority of our cells are in a state known as ‘differentiated’, which means that they cannot change their cell type. For example, a neuron cannot change into a blood cell, and a skin cell will not become a pancreatic cell. Cells become what they are during embryogenesis from ‘undifferentiated’, or stem cells. Undifferentiated cells have the potential to transform into different cell types. Adults have stem cells in their bone marrow, and their purpose is providing the raw material for the constant production and renewal of blood cells. Stem cells are very important for medical research because scientists have realized that stem cells can be ‘trained’ to generate a specific kind of tissue. For example, stem cells could be induced to become skin cells and grow into actual skin that could be used to cure severe burns or other skin damage. Many other applications are being developed, such as leukemia treatments.
The purpose of storing umbilical cord stem cells
Developing babies lack bone marrow. The stem cells they need for producing bone marrow after birth are found circulating in the bloodstream. Stem cells in a newborn’s blood is ten times more concentrated than what you find in the bone marrow. When the baby is born, it is possible to collect umbilical cord blood from which the stem cells can be purified and stored in a cord blood bank. These cells can be used as a replacement for bone marrow if a transplant is needed. Since the source is the umbilical cord that would otherwise be thrown away, there are no risks for the baby. Cord blood is then cryogenically preserved at extremely low temperature under liquid nitrogen. It is believed that in these conditions, stem cells will be viable for more than 15 or 20 years.
How can the stored stem cells be used to treat diseases?
One of the main objectives of current research is treating blood cell disorders. One strategy would be using chemotherapy to get rid of existing bone marrow, which is affected by the disease. Then the stored umbilical stem cells would be injected into the bloodstream where they will find their way to the bone marrow cavity. Once there they will settle and produce a new bone marrow tissue. This is just an imitation of what happens in a newborn baby.
Adapted from http://www.thenakedscientists.com
