Polymers promote nerve cell growth.

• Position: Regeneration - Brief Article

Using microscale channels cut in ultrathin biodegradable polymers, Surya Mallapragada, a chemical engineering professor at Iowa State University, Ames, and an associate in materials chemistry at the U.S. Department of Energy's Ames Laboratory, is working to regrow nerve cells. The technique has been proven to work for peripheral nerve regeneration in laboratory rats.

When a nerve is severed, the part of the neuron "downstream" of the injury typically dies off. Neurons in humans are several feet long. Grafting, which works well for other tissue such as skin, isn't the best option because of loss of nerve function where the donor tissue is removed and the difficulty in getting the nerve cells to line up and reconnect. "Nerve cells aren't able to easily bridge gaps of more than one centimeter," Mallapragada explains. "Peripheral nervous system axons--the part of the nerve cell that carries the impulses--normally have a connective tissue sheath of myelin guide their growth, and without that guidance, they aren't able...