Advancements in stem cell therapy

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Advancements in stem cell therapy Tue 11 Apr 2006 11:16 AM CST
MINNESOTA (myDNA News)

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The prospects for stem cell repair of the nervous system may be advanced by the use of cells derived from bone marrow and the use of a hydrogel to direct cell growth, according to two studies that were presented last week at a special session on stem cell research at the annual meeting of the American Academy of Neurology in San Diego, Calif.
The first study explored the therapeutic potential of bone marrow-derived multi-potent progenitor cells. These cells have the ability to develop into a variety of cell types, including cells of the nervous system, according to Cesar Borlongan, Ph.D., of the Department of Neurology at the Medical College of Georgia.
Borlongan and his colleagues tested the potential of both human and rat stem cells to repair the nervous system in rats with experimentally induced stroke. Within a week of transplantation, both human and rat stem cells led to dose-dependent reductions in motor impairments.
In neonatal rats, transplanted cells migrated out from the transplant sites toward another nearby brain region. There was no evidence of tumor formation, a possible adverse effect of stem cell transplantation.
The second study addressed a significant problem in the use of stem cells for spinal cord repair — that of directing cells to align in the proper direction along the cord. Misdirected or undirected cell orientation limits the ability of injured nerves to reconnect with other nerve cells further down the spinal cord.
"A regrowth-directing structured scaffold is required for spinal cord repair," said lead study author Norbert Weidner, M.D., of the University of Regensburg, Germany.
The research group tested anisotropic capillary hydrogels (ACH) made of a seaweed derivative, which have an internal structure that preferentially guides axons (nerve cell extensions) in one direction. In brain slice cultures, they showed that ACH promoted regrowth of existing axons and improved their ability to reconnect with their target nerve cells. They then tested this strategy in adult rats with damaged spinal cords, where ACH promoted directional regrowth across the scaffold.
Ongoing studies demonstrate that ACH can be "seeded" with neural stem cells, which now align properly and may further enhance the regenerative capacity of ACH.
"ACH represents a promising strategy to induce nerve regrowth following spinal cord injury," Weidner said. "Several additional strategies could be used to improve the success of this therapy, including adding various growth factors and drugs to the gel to enhance nerve cell growth."
This information was provided by the American Academy of Neurology.