Induced Specificity of Stem Cells in the Spine

Scar tissue presents a difficult roadblock for surgeons and patients alike. Scar tissue is connective tissue that forms as a result of trauma, often inhibiting the healing process and forming a weaker bond between two tissues compared to the pre-incision tissue. New procedures in medicine and in the operating room stress the minimization of incisions time spent under the knife in an effort to reduce the amount of recovery time and the amount of scar tissue.

Spinal cord injuries affect as many as 250,000 patients in the United States, 11,000 each year. The average lifetime cost, per patient, of a spinal cord injury is about $1,350,000. As of now, there is no effective treatment for severe spinal cord issues as a result of damaged myelinating oligodendrocytes on the spinal cord and the delocalization of ion channels on the axon membrane. While the applications of stem cell treatments can be affective, often these areas are inaccessible due to scar tissue.

According to Dr. Hui Ye, Ph.D. in Loyola University Chicago's Biology Department, reducing scar tissue is only half of the battle. Specifically in patients with spinal trauma, the death of myelinating oligodendrocytes is quick and irreversible, results in weak nervous signalling, and causes severe peripheral neuropathy. Ye believes that the introduction of stem cells into damaged tissue, the "blank slate" cells could regenerate damaged tissue (regenerate is used loosely, stem cells form new cells) and relocalized Potassium channels and re-myelinate axons in the spinal cord.

But, Ye encountered his first major roadblock: scar tissue. Stem cells cannot be expected to localize to specific areas on their own and cannot be forced through scar tissue, a physical collagen barrier. While he proposed the used of stem cell galvanotaxis - the use of electrical signals to motivate cells to migrate - to move stem cells to affected areas of the spinal cord post-surgery, I believe that the problem may lie in the scar tissue itself. Ye's stem cell galvanotaxis could definitely be used to transport cells to traumatized areas, but various methods exist of removing incision-related scar tissue in the body. Ye is trying to force stem cells through scar tissue with the use of galvanotaxis, but I believe his efforts would be better utilized at trying to reduce the amount of scar tissue before applying stem cells. 

Firstly, permanent, collagenated scar tissue does not occur immediately after healing. If stem cells were introduced into the damaged area immediately after surgery, doctors would not necessarily need to bypass scar tissue to apply stem cells to the affected areas, as it would not have formed yet.

Secondly, there are multiple, verified methods of removing scar tissue. For example, Ravi Bellamkonda, a biomedical researcher at the Georgia Institute of Technology Research and Emory University has identified a type of enzyme - harvested from bacteria - that breaks down collagen fibers in scar tissue, allowing for the access of affected areas. While treatments are still in the early stages and the enzyme breaks down very easily when exposed to heat, it is a promising start for alternative methods of dealing with scar tissue.

In summary, Ye's research is relevant concerning the specificity of stem cell localization. In addition, galvanotaxis can most likely be used to direct stem cells to affected areas. But, galvanotaxis must be paired with verified methods of treating scar tissue if it is to be effective; pursuing methods of forcing stem cells through scar tissue, as Ye is doing, seems counterintuitive and unrealistic.

http://topics.wisegeek.com/topics.htm?incision-scar-tissue#

http://www.reuters.com/article/2009/11/02/spine-repair-idUSN0226708720091102