Polymer May Allow Soldiers With Artificial Limbs To Feel Heat, Cold, Touch

Physicians at the American Society of Plastic Surgeons (ASPS) Plastic Surgery 2009 conference, Oct. 23-27, in Seattle, reveal they have discovered an electrically conducting molecule or polymer (3, 4-ethylenedioxythiophene or PEDOT) that helps stimulate and grow new nerve fibers in severed nerves of amputees. Stimulating and growing nerve fibers are one of the first steps in providing amputees more neurologic control over their prosthetics.

The research, conducted through a $5.5 million U.S. Department of Defense grant, may give amputees the ability to move fingers independently, apply the appropriate amount of pressure to objects to better grab and lift something as delicate as Styrofoam cup, and feel sensation.

In one study, plastic surgeons may have found a way to successfully grow new nerve fibers, after they've 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, along with other biologic and synthetic materials, and grafted into the severed leg nerve of a rat. New nerve fibers grew and took over function for the dead or dysfunctional severed nerve springing targeted muscles to life.

In another 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 study 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.

Nearly 5 million reconstructive plastic surgery procedures were performed in 2008, up 7 percent from 2007, reports the ASPS.