‘Spider-Man’ develops web
He’s no Peter Parker, but Randy Lewis, professor of biology at USU, is broadening the horizons of the work that can be done with spider silk.
Often referred to as “Spiderman” by his co-workers, Lewis started researching and working with the properties of spider silk at the University of Wyoming, where he worked for 30 years before coming to Logan.
“Spider silk is the strongest biological material that exists,” Lewis said. “It’s still flexible, and it’s still elastic. That is one of the key differences between it and materials like Kevlar.”
Earlier this week, Lewis was interviewed on CNN. Next Tuesday, BBC will be interviewing him as well.
Randi Kaye, the CNN reporter who talked to Lewis, said “This is really interesting — a little bizarre — but really cool at the same time.”
The average spider makes six different types of silk in the typical circular orb-shaped web, Lewis said. Each type of silk has different mechanical properties.
“Some are as elastic as rubber; some are stronger than Kevlar. There are those that have no stretch at all,” he said. “Some of them, they don’t even know the properties because of the way it is spun.”
The hardest part of this research is figuring out the best way to produce the silk in mass quantities. Each web is made from four types of silk. You can’t just go collect webs because you won’t get anything from it.
The spiders are also very territorial and cannibalistic, so they do not survive long enough to make enough silk, he said.
To solve this, the genes for each type of silk have been pulled from the spiders and are being cloned. Later, the genes are transferred into goats and the silk proteins combine with the goats’ milk, Lewis said. The genes are also being transferred into silk worms who combine the spider silk with their own.
“We’re still going strong with the goats; we’re still going strong with the bacteria, and we’re starting to work with alfalfa,” he said.
The goal is to create a material that can combine strength and flexibility. To produce the proteins Lewis and other scientists use bacteria.
“They are easy and fast. I make up a new gene and in months it’s ready,” he said. “They make it, we spin the fibers.”
Eventually the silk material will be used and sold for a variety of items.
The item highest in demand will be material to repair tendons and ligaments. Right now, if you tear your anterior cruciate ligament (ACL), there are no repair methods, he said. It can be replaced by using pieces from elsewhere in your body or from a cadaver.
If you tear your rotator cuff, tendons can be sewn together. For someone younger, it will most likely repair and heal just fine. For someone older it’s just going to make scar tissue, he said.
“Scar tissue is much weaker than the natural tendon,” Lewis said. “We can put this in there and hold the ligament together and then do some physical therapy rather than completely immobilizing it; so it will heal (to) a level of at least moderate use.”
Lewis said there are companies interested in using the silk materials for a variety of products.
“People have contacted me about using it for parachute cords and for catch lines in aircraft carriers as opposed to steel and springs,” he said. “A lot of the things are to use it as a replacement for tools. I’ve been asked about everything from fly fishing materials to airbags.”
Jalila Essaidi, a Dutch bio-artist heard about Lewis’ research and contacted him about her idea to create “bulletproof skin.” The two have worked together to design and manufacture the skin for testing.
“One of the goals while producing the silk was to create bulletproof vests and I thought, why even bother with the vests, let’s go directly to the skin,” she said.
Essaidi shot the piece with a .22 caliber rifle at a slower than normal speed. The bullet did not penetrate the skin, but it did put enough pressure on it that enough damage would still be caused to seriously injure or kill a person.
“It’s not bulletproof right now,” Lewis said. “Perfecting it is not high on our list right now.”
With all the recent national publicity, Lewis said more companies have contacted him about their ideas for the silk.
“Tell me what you want and the price you are willing to pay,” he said. “Then I can tell you if that’s something we can do. “
Lewis said he enjoys his research because it is something the average person is likely to understand. Since arriving in Logan, he has discussed the project with everyone from 3rd grade students to Rotary Club members to graduate students.
“It’s easy. Everyone knows what a spider web looks like,” he said. “It’s easy to talk to people about it.
— megan.allen@aggiemail.usu.edu