GAITHERSBURG — GAITHERSBURG -- Using light waves, polymers and a nuclear reactor, researchers here are investigating a superstrong, experimental gel that might some day turn into a novel treatment for millions of people who suffer from arthritis.
Scientists at the National Institute of Standards and Technology have spent two years shooting neutron beams at the mysterious hydrogel, trying to determine why it is almost as strong, flexible and resistant to friction as the cartilage in the human knee.
The polymers in the gel - formed when synthetic molecules are struck by ultraviolet light - were developed by researchers at Hokkaido University in Japan in 2003. The report of their discovery intrigued Wen-li Wu, a materials scientist at the NIST, who began testing them shortly afterward.
His goal: a gel that could serve as both a coating for the materials used in knee and hip replacements and as a kind of caulk to plug holes in damaged cartilage.
"The idea is to give time for the body to heal so cartilage can grow," Wu said.
Wu and other scientists are part of a small but intense community developing biomaterials that can mimic or supplement what our bodies do every day: repair and replenish the cartilage in our joints. If they can inject these synthetic repair materials into aching, arthritic joints, it could reduce the need for many of the 1 million knee and hip replacement surgeries performed each year, experts say.
"It's pretty amazing stuff. I think it's something definitely worth exploring," said Dr. John Hardin, chief scientific officer of the Arthritis Foundation and a professor of orthopedic surgery at the Albert Einstein Medical College in New York.
To figure out what was going on inside the Japanese polymers, scientists used NIST's Small Angle Neutron Scattering Instrument, which was able to decipher the molecular structure of the polymers as they were hit with neutrons created by the agency's small research reactor.
They announced their findings in a paper earlier this month at the American Physical Society meeting in New Orleans.
At the molecular level, they concluded, the two polymers that make up the gel join together in tightly linked chains when hit with ultraviolet light. The result is a substance with the consistency of a slightly stale gummy bear that might ultimately increase the lifespan of joints that are wearing out.
