U., Y. effort targets prosthetic infections

Sgt. 1st Class Dan Gubler dreams of a prosthetic arm that attaches directly to bone in his right arm, which had to be amputated above the elbow after he was injured in Iraq.

The technology for prosthetic arms hasn't quite caught up with that for legs, although it's getting there quickly, says the member of the National Guard. But there is still another issue that has to be overcome: Whenever something goes directly into the body and extends outside, whether it's a catheter or a limb, there's huge risk of serious infection. And many of the infections are resistant to two or even three existing antibiotics.

A collaboration among researchers at the University of Utah, Brigham Young University and a company called Ceragenix Pharmaceuticals may yield the breakthrough that will solve the infection problem.

Using a grant the U. secured from the U.S. Department of Defense and U.S. Department of Veteran Affairs, the U. will test a novel product that is based on BYU research and licensed to Ceragenix.

A team of researchers at BYU, led by Paul Savage, professor of chemistry and biochemistry, created a molecule that mimics the antimicrobial agents produced by bodies across the animal kingdom. They naturally fight harmful bacteria, which have not become resistant to them, as they have to so many man-made antibiotics.

The naturally occurring antimicrobials are expensive and not stable, so efforts to produce them commercially have failed, while the molecule the BYU lab created is just the opposite. It's cheap, reproducible and kills bacteria in the same way. They patented and licensed it to Ceragenix, which is developing forms that can be placed at the point where an implant leaves the body. Savage says the antimicrobial slowly dissolves, so it kills bacteria for a long time. By attaching it to a polymer, the scientists were able to extend its effectiveness well beyond that of the naturally occurring antimicrobial. But it kills the bacteria quickly.

Bone spurs that form in the muscle and nerve tissue, making traditional prosthetic sockets attached to stumps uncomfortable, are yet another reason the 500 amputees injured in Iraq and Afghanistan are so anxious for implantable limbs, says Roy Bloebaum, research professor of orthopedics, bioengineering and biology at the U., who also heads the Bone and Joint Research Lab.

The key to moving implantable prosthetics forward, he says, is having a way to prevent infection. Without it, it's like pulling weeds and leaving the roots. This antimicrobial seems to work against a broad spectrum of bacteria.