Orthopedics specialists have developed a new injectable “bio gel” that promotes healing of knee injuries by repairing cartilage and preventing osteoarthritis.

The University of Iowa research team said the gel could offer a minimally invasive, practical, and inexpensive alternative to knee surgery and other treatments for the millions of professional athletes, college sports stars, and weekend warriors who suffer cartilage damage and arthritis.

"We are creating an [injectable, bioactive] hydrogel that can repair cartilage damage, regenerate stronger cartilage, and hopefully delay or eliminate the development of osteoarthritis and eliminate the need for total knee replacement," said Yin Yu, a UI graduate student helped develop the compound with James Martin, an assistant professor of orthopedics and rehabilitation.

The gel, which was featured on the cover of the May issue of the journal Arthritis and Rheumatology, was developed as a result of research into molecular mechanisms that can lead to the growth of new, normal cartilage in people with knee injuries.

In laboratory tests, the team demonstrated that injecting the custom-made hydrogel into holes punched into cartilage led to the growth of normal cartilage that repaired the injury.

In effect, the researchers suggested the technique could help people with knee injuries regrow their own cartilage, which cushions and supports damaged joints.

"This process gives us a great result," Yu says. "The new cartilage integrates seamlessly with the undamaged tissue, it has … good structural properties and looks like normal cartilage."

The new tissue is not as strong as normal cartilage, but Yu and Martin suggested physical therapy and exercise might help build its strength.

"There's really no cure for osteoarthritis except for total joint replacement, which is not particularly suitable for younger patients because the artificial joints wear out and need to be replaced multiple times," said Martin. "Our approach aims to leverage the body's own capacity for repair, and what we've shown is that cartilage does have regenerative potential; you just have to manipulate it just right."

Yu and Martin will now test the gel in animal and, if the results are promising, they hope to start human trials in about five years.