Scientists get up noses with squid gel (11/25/2007)

A squid-derived wound-healing gel invented by University of Otago scientists is attracting attention from international medical companies, due to its unique blend of properties.

The "Chitodex" medical gel, which uses a polymer derived from squid, has been patented by researchers from the University's Department of Chemistry.

Research team leader Professor Brian Robinson says Australian medical trials show the gel possesses both anti-bleeding and anti-scarring properties.

"This is a very exciting discovery for us. This combination makes it the 'Holy Grail' of medical gels. It could potentially help a lot of people around the world by reducing complications in sinus surgery and other surgical procedures," Professor Robinson says.

Half a million endoscopic sinus operations to relieve sinusitis are performed every year in the United States alone. In New Zealand, the figure is several thousand.

In around a third of these surgeries, a type of scarring known as 'adhesions' occurs, which can block sinus passages and require further surgery to correct.

The Otago scientists started work on the gel after Professor Robinson's son, who is a Wellington ear, nose and throat surgeon, asked his father to come up with something to help solve the problem.

The team's collaborators at the University of Adelaide's medical school are currently undertaking patient trials, following the gel's highly impressive performance in preventing adhesions when tested in sheep, he says.

"Sheep were used because they have a very similar sinus set-up to humans. Our colleagues in Adelaide, headed by Professor Peter-John Wormald, are world-leaders in this kind of research," he says.

The gel's special properties also allow reduced bleeding during an operation, allowing surgeons a much better view of the delicate structures they are operating on and around.

Dr Stephen Moratti, the team's polymer expert, says they were surprised and delighted to discover that the gel also had an innate anti-bleeding action.

"We thought we would have to combine another chemical with the gel to get this property, but it was already there."

Like the commercial glue Araldite, the non-toxic hydrogel is prepared by mixing two tubes of ingredients together immediately before it is sprayed up the patient's nose.

Within a minute, it forms into a thick and sticky layer, which slowly leaves the nose over a couple of days, says Dr Moratti.

The gel's active ingredient is a chemically-modified form of chitosan, a biocompatible polymer derived from the bony part of squid - the pen - and crabs, he says.

"Squid are an abundant renewable resource in our waters, so this potentially could lead to new export earnings based on the chitosan from squid pens. In New Zealand, these pens are usually thrown away during seafood processing," says Professor Robinson.

International medical companies have already expressed interest in developing the gel further, while New Zealand Pharmaceuticalsis investigating the feasibility of large scale production of the modified chitosan, he says.

The Otago team is currently working on refining the gel's formulation to aid wound-healing in cosmetic and abdominal surgery.

"While it is still very early days, we believe that it may have even greater potential for these kinds of procedures," says Professor Robinson.

Across the Tasman, the potential of the gel is already being recognised. The University of Adelaide has recently presented the team's Australian collaborators with a "Most Exciting New Disclosure" prize.

The Otago gel research is being supported under a "Smart Polymers" grant from the Foundation for Science, Research and Technology New Economy Research Fund.

Note: This story has been adapted from a news release issued by the University of Otago

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