X-Message-Number: 13451 Date: Sat, 01 Apr 2000 18:25:00 -0500 From: Jan Coetzee <> Subject: Metal-like plastic stimulates nerve regrowth Metal-like plastic stimulates nerve regrowth SAN FRANCISCO, Mar 31 (Reuters Health) -- In laboratory experiments, a plastic that conducts electricity much like a metal has been shown to stimulate nerve regrowth when it is wrapped around severed nerves. Dr. Christine Elizabeth Schmidt, a chemical engineer at the University of Texas at Austin, said that the special plastic also doubles the rate of new blood vessel growth. This is a crucial step to both nerve regeneration and wound healing. Electrical fields and conductivity have long been known to enhance the healing of bone, nerve and other tissues, Schmidt said here at the national meeting of the American Chemical Society. The reasons are not fully understood, but probably involve changes in how proteins are absorbed, or how calcium moves around in the cell in the presence of electrical fields. Currently, in cases of severe nerve damage in the arms or legs, where a large section of nerve is lost -- as from an auto accident -- surgeons must harvest a nerve from a less vital part of the body and suture it to the injured nerve. But this requires two surgeries, and causes injury to the area of the body where the donor nerve was harvested. In the current experiment, no outside electrical current was sent to the plastic around the severed nerves of rodents. Schmidt has just begun to study whether sending a mild electrical charge through wires to the plastic will further speed regrowth. The special plastic, called polypyrrole, is an electroactive polymer. Schmidt has found the plastic to be safe when used surgically. She is also developing a form that will dissolve naturally in the body after the nerve regenerates. The next step is to experiment with polypyrrole in larger mammals. If the plastic eventually proves successful for regenerating nerves in human limbs, it might someday be used for nerves in the spinal cord -- a much more difficult problem, Schmidt said. ``We're working with some surgeons who are very interested in this,'' she added. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=13451