Alzheimer's, Parkinson's, multiple sclerosis, and injuries to the brain or spinal cord - the list goes on. Diseases and disorders involving neural tissues affect many people. Before researchers broadened their horizons, few had an optimistic outlook when it came to a cure. In the adult body, cells called neurons are incapable of growth and repair. Without functioning neurons, electrical and chemical signals cannot be transmitted throughout the brain and on to other parts of the body.
Thanks to the advances in stem cell-based therapy, however, neural tissue repair and neural tissue regeneration are now possible. The key is the self-renewal and differentiation of stem cells, a class of cells which replicate themselves into cells with similar properties in order to maintain a pool of precursor cells. In turn, these precursor cells use natural processes to form cells such as neurons. Biomedical engineers can use stem cells in various ways, but let's start by discussing where these cells come from.
Embryonic or fetal tissue is the best known source of stem cells, largely because the scientific world has been engulfed in a political battle over their use. But did you know that adult stem cells can also be extracted from bone marrow and skin? By expanding these stem cells in cultures, neurological cell lineages can be obtained. Other sources of stem cells include the umbilical cord, the developing brain and bone marrow of adults, and the placenta.
Today, stem cells can be isolated and placed in conditions to form neural lineage cells which promote functional recovery after spinal cord injuries. Laboratories are trying different methods to culturing these tissues in order to determine the best approach. Research indicates that plated postpartum-derived cells (PPDCs) provide soluble and/or contact-dependant mechanisms which lead to neural progenitor survival, proliferation, and possibly differentiation. By definition, PPDCs are not embryonic stem cells.
Once cell culturing is complete, stem cells can be injected or infused into the body with a pharmaceutically-acceptable carrier. In the case of neurodegenerative diseases and injuries, this carrier can be delivered to the patient by implanting cells in the cerebral spinal fluid. Alternatively, delivery can be achieved through surgery upon the damaged area.
Are biomedical engineers using stem cells? Yes! At the Beijing Tiantan Puhua Hospital, researchers are practicing the process of obtaining stem cells from bone marrow. The cells are then cultured and proliferated into mesenchymal stem cells (MSC). There are many exciting possibilities in this area of research. Someday, neurodegenerative diseases and neurological tissue damage may have a cure.
Resources:
http://www.puhuachina.com/?gclid=CMyz3ufIiY0CFSgRGgod-g5opg
-Contains information on the Tiantan Puhua hospital, their research, and patient stories
http://www.freepatentsonline.com/20050032209.html
http://www.puhuachina.com/?gclid=CMyz3ufIiY0CFSgRGgod-g5opg
RPI Research in neural engineering
http://www.eng.rpi.edu/soe/directory_faculty_details.cfm?facultyID=thompd4
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