In recent years there has been considerable interest in developing strategies to repair damaged peripheral nerves through the use of transplanted materials of various types. While some of these efforts have shown promise, one of the major obstacles in this work has been the relatively long distances that cell processes must traverse in order to establish functional connections. A unique strategy that has recently been identified in Dr. Douglas Smith's laboratory is the technique of stretch-induced growth of nerves in an in vitro system. Using a motorized device to slowly pull connected neurons away from each other, we have been able to elongate axons of several types to a length of 5 cm over a 2 week period. To date, integrated neuronal cultures of primary rat cortical neurons and human neurons from the NT2 cell line have been successfully elongated in this system. In this study, we plan to examine adult rat DRG cell's ability to undergo elongation under continued mechanical tension. The elongated nerves (axons along with Schwann cells) will then be used as graft materials to bridge long gap of sciatic nerve defect in rats. Outcomes will be measured through the use of functional testing, electrophysiological testing and histology. Positive results from this study may lead to new breakthrough in repairing peripheral nerve damage using tissue engineering techniques.
