University of Wyoming team leads in research of silk

When a team of University of Wyoming researchers discovered and mapped the genes responsible for spider silk in 1989, the findings opened the door to military and medical applications like spider silk body armor and artificial tendons.

Made of fibers that are 10 to 100 times smaller in diameter than a human hair, put together in a clothlike material, spider silk is tougher and weighs three times less than Kevlar – a plastic fiber that is used in bulletproof vests.

Associated Press

http://www.billingsgazette.com/index.php?id=1&display=rednews/2004/01/05/build/wyoming/30-silk.inc

Used for medical sutures, artificial ligaments, and artificial tendons, spider silk could increase the success rate for surgeries.

Today, after 15 years of work on spider genes, led by Dr. Randy Lewis, the University of Wyoming is the worldwide leading authority in this scientific area.

"When it comes to spider silk genes, we are the leading authority, without a doubt," Lewis said. "Most of the people are not doing it anymore, because they know that if there is something out there, which is interesting, we are going to beat them to it."

The Lewis team has already published substantial studies on the spider genome in the world’s most reputable scientific journals, but UW scientists continue to make major discoveries each year.

"If you make a major discovery once a year, you are having a heck of a life as a scientist," Lewis said. "We have cloned and sequenced the genes from 26 different species of spiders – two a year."

Finding the gene

Scientists have known the properties of spider silk for centuries; they’ve just never been able to produce enough to make it commercially available. With the advent of genetic engineering, UW scientists pioneered the idea to take spider genes and introduce them into other species.

To discover the genes, UW scientists took a small piece of DNA they hoped matched the spider silk-producing gene, and introduced it into bacteria, hoping the micro-organism colonies would exhibit the silk-producing qualities found in spiders.

After weeks of tests, they found the right gene.

"Once you knew you had the right one, the rest is technologically challenging but not intellectually challenging," Lewis said.

When it became clear it was not cost efficient to use bacteria in large-scale spider silk production, UW started to cooperate with Canada-based Nexia Biotechnologies to produce spider silk proteins in goats’ milk.

"We took the genes and spliced them into goats in a way that they are only produced in the milk," Lewis said. "It’s not the first gene that anybody has done it with it’s the first in which they are looking for a fairly large amount of material."

Producing a large amount of spider silk is key to the material becoming commercially applicable.

"Nobody has been able to produce enough," Lewis said. "It’s not easy."

To make a 5-pound bulletproof vest, a producer would use 600 gallons of goat milk containing the silk protein. The milk production from 200 goats in one day would be used for just one vest.

As a result, the UW team is also considering introducing the silk gene into alfalfa, a plant proven to grow well in the Wyoming climate. Research is ongoing, and if it is successful, Lewis says using alfalfa could be economically viable.

Even if the price is lowered to a minimum, spider silk body armor could come with a price tag twice that of Kevlar-based body armor. Lewis said the U.S. military will be willing to pay for it, because the material is light and elastic.

"I can’t really imagine that I am out in Iraq with 16 pounds underneath my vest and it’s 110 degrees out there – and I can’t bend," Lewis said. "If you can cut weight and make it that more flexible, you are going to have soldiers that are a whole lot more effective."

Creating variations

Despite the technological difficulties of bringing spider silk products to the market, Lewis said he is moving into the next stage of the intellectual research.

Composed of 16 researchers – four postdoctoral, four graduate, and four undergraduate students – the team is now looking at manipulating genes to create silk that varies in elasticity and strength depending on the specifications needed for its use.

Dragline silk – used mostly by predator spiders and known for its elasticity and strength – has been the focus of this research. UW scientists have discovered that the thinner the diameter of a fiber, the stronger the material made out of it.

"The thinner the fibers are the more accurately they are put together," Lewis said. "Evolution has taught spiders that it’s a lot easier to wrap 100 little fibers to capture prey than one big one."

The spider silk research has put Laramie and Wyoming on the world’s scientific map – especially when it comes to media and public attention, Lewis says. Quoted in the world’s largest English-speaking newspapers and featured in nationwide television newscasts and documentaries, the spider silk research has built on UW’s reputation.

"There are a lot of other things being done in the university that are scientifically challenging, but people can’t relate to them as easily as spider silk," Lewis said.

Furthermore, the research is done by students from Wyoming, including undergraduates and graduates.

"People have become very successful," Lewis said, "taking the perception of most people from the outside – even from Wyoming – they have been able to do that."

Lewis said some people think athletic programs build a university’s reputation, and he agrees with them to a degree. But he says internationally recognized research can do the trick better.

"I think that there are an awful lot of institutions who have a reputation for being intellectually challenging and intellectually stimulating," Lewis said. "I hope – through the publicity we get for the spider silk research – that’s what comes across for the University of Wyoming."

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