Rootsie

the wonders of nature....

Frog glue repairs damaged cartilage
By Rachel Nowak, Melbourne

A sticky substance secreted from glands on the back of two little-known species of burrowing Australian frog has been used to repair torn cartilage in the knees of sheep.

The frog glue is being developed by Australian researchers as an adhesive to treat hard-to-repair human knee injuries as well as a range of other medical applications.

The frogs - of the Notaden genus - live 1 metre underground in dried mud for nine months of the year, emerging only during torrential rain. On these occasions they are vulnerable to insect attacks and so secrete the glue to jam the jaws of biting insects like ants, sticking them to their skin, which they eat later.

“All species of frogs shed their skin once or twice a week, and then eat it. It’s a revolting sight,” says Mike Tyler of Adelaide University, who discovered the frog glue.

Moist habitat

The frog glue hardens in seconds and sticks well even in the frog’s moist habitat. “We assumed the substance would be toxic, but when we found it wasn’t, it made sense to explore it as a medical adhesive,” says Tyler.

The frog glue could plug an unmet need for strong and flexible medical adhesives, researchers believe. Available synthetic glues such as cyanoacrylates - the main ingredient in Superglue - are strong, but can be toxic and brittle.

Biological glues, such as those based on fibrin - the sticky component of blood - are too weak to fix parts of the body that have to withstand strong forces, such as an injured meniscal cartilage, found in the knee.

Meniscal cartilage acts as the knee’s shock absorber. It is often damaged during sports such as skiing, and deteriorates in the elderly. Although meniscal tear surgery is one of the most common orthopaedic procedures, less than 10% can be repaired with current techniques, which involve suturing.

“There is a great need for something strong enough to withstand the forces in the knee to hold the cartilage together until it repairs,” says biomaterials expert Rolfe Howlett of the University of New South Wales in Sydney.

Reconstructed joints

In the sheep experiment, orthopaedic surgeon George Murrell of the University of New South Wales made a tear in the meniscal knee cartilage of ten sheep, treated each with frog glue, and reconstructed the joints.

Ten weeks later, Tyler and Murrell examined the sheep’s knees. The frog glue had held the cut fragments together, and collagen, the main component of cartilage, had filled the gap.

Tyler and colleagues - including John Ramshaw of the Commonwealth Scientific and Industrial Research Organisation in Melbourne - have also shown that the frog glue will stick plastics, wood, glass, metal and Teflon. It is strong even in moist conditions.

The set glue is also flexible and has a porous structure that should make it permeable to gas, nutrients and possibly even cells, which would encourage healing.

Ramshaw and his colleagues have also characterised a key component of the glue, a novel protein unrelated to other biological adhesives such as those used to stick barnacles to surfaces. They are now developing a genetically engineered version of that protein.

The findings were presented on 28 September at ComBio2004, a biological science meeting in Perth.

http://www.newscientist.com/hottopics/tech/article.jsp?id=99996492&sub=Medical

perhaps ones will no longer just lick toads to hallucinate, perhaps they now can turn to sniffing frog glue.

well.....if licking toads in this case were true...it would appear that one would have a toad stuck to the end of their tongue .. [smiley=tongue3.gif]