U., Y. Effort Targets Prosthetic Infections
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.
Antibiotics work by interrupting some part of bacteria's reproductive process, says Steve Porter, CEO of Ceragenix. This works by killing the bacteria outright. He describes a small foam disk like a poker chip, impregnated with the molecule, with a hole in the middle so it slides around a catheter, tube or whatever comes out of the skin, snug against the body. The foam elutes a small amount of the antimicrobial, which keeps the device from being colonized by bacteria. So far, he says, it has been "phenomenally effective" in the lab and limited animal testing.
Bloebaum and his colleagues are using part of their grant to purchase and test the product, in which the U. has no investment. If it works, it will likely be used with the Dartmouth arm and other devices, but first the U. will test it on metal parts, not people. A great deal of work can be done in the lab to check effectiveness, Bloebaum says.
The U. has a four-year grant for its work on infection prevention in use of implantable prosthetics.
By Lois M. Collins
Deseret Morning News
