Flexible, resilient gel may replace damaged cartilage

London, March 13 : US researchers are investigating whether a flexible, resilient gel has the potential to be used as artificial cartilage to repair ailing joints.

The water-based gel is made of polymers commonly found in shampoo. It is believed that this gel may prove to be a boon for millions of people who are suffering from joint diseases like arthritis.

"You can squeeze it or pull it by 10 times its original length and it still won't fall apart. If you tried to do that with Jell-O (jelly) or any other material that was 90% water it would just fall apart," New Scientist magazine quoted Eric Lin of the US National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, as saying.

The gel was first created in 2003 by researchers at Hokkaido University, Japan. The researchers made it by mixing two polymers with water in a specific ratio.

Lin and his colleagues have now revealed the gel's atomic structure by blasting it with neutrons, and uncovered precisely what happens to it when stressed.

The researchers have found that the two polymers form strong integrated bonds at regular intervals across the compound. However, when the gel is deformed, such bonds can temporarily break apart to release tension before reforming.

"Instead of one big crack, its like tens of thousands of small micro-cracks that work like mini shock absorbers at every micron along the material," say Wen-li Wu, also of NIST.

The researchers say that understanding how the material holds together under stress may have strong implications for the designing of an artificial cartilage material.

Anthony Hollander of Bristol University, UK, was the first to prove that lab-grown cartilage can benefit patients, says: "The great advantage of their approach, if it really works, is it's an off-the-shelf technique," Hollander says. "Growing the patients' own cells in an ultra-clean lab is expensive."

He, however, believes that cartilage is highly complex tissue that may be hard to replace, and if artificial cartilage is implanted to fill a gap of missing tissue, it may result in pressure points where it brushes up against existing cartilage.

"My guess is for the most challenging patients we will need a laboratory engineered, natural tissue," Hollander says.

A paper on the artificial cartilage was presented at the American Physical Society meeting in New Orleans, US.

ANI