Bringing Real Feeling to Artificial Limbs

Reported October 28, 2009

(Ivanhoe Newswire) -- Plastic surgeons have discovered an electrically conducting polymer (3, 4-ethylenedioxythiophene or PEDOT) that helps grow new nerve fibers in the severed nerves of amputees, which may provide neurologic control of prosthetics.

Current prosthetics may look natural, but they are still primitive, offering patients no real neurological control. But for U.S. soldiers who have lost arms and hands in the battlefield, two new studies may bring "real" feeling to artificial limbs.

Stimulating and growing nerve fibers is the first step toward providing amputees neurologic control over their prosthetics. The research may give amputees the ability to move fingers independently, better grasp something as delicate as a Styrofoam cup and, most important, feel sensation.

In one study, plastic surgeons may have found a way to successfully grow new nerve fibers after they have been severed due to injury through the electrically conducting PEDOT polymer. PEDOT functions similar to a wire. In the study, the PEDOT was placed in a tube and grafted into the severed leg nerve of a rat. New nerve fibers grew and took over function for the dead severed nerve, springing targeted muscles to life.

In a second study, plastic surgeons designed a cup containing cells and muscle that fits around the severed leg nerve of a rat. The PEDOT polymer was wrapped around all of the cells and muscle in the cup to provide an electrical charge. Tests were conducted 114 days after the procedure. The researchers found new muscle and blood vessels formed, nerve fibers sprouted, and muscle fibers started compensating for lost nerves. After tickling the rat's paw, doctors' were able to pick up electrical signals indicating sensation had returned.

SOURCE: Presented at the American Society of Plastic Surgeons (ASPS) Plastic Surgery conference, Seattle, October 23-27, 2009