A spider web is a type of wonder fiber. It is six times as strong as steel fiber. That means that if a spider web were the thickness of steel fiber, it could bear six times as much weight as steel fiber without breaking. Spider webs are also very resistant to water, cold, heat, and fire. Microscopic threads that can be spun from them are suitable for the software, medical, and nano-technology engineering industries.
Up until now, the problem with spider webs has been the spider. In contrast to silk worms, which have been used for thousands of years to make thread everywhere from kindergartens to giant industrial plants, the spider is not so easy to domesticate.
Spiders are territorial creatures, which do not like communal living. It is impossible to raise masses of spiders on a single farm. Prof. Uri Gat of the Hebrew University of Jerusalem had to grow spider webs by himself, without the help of the weak link in the chain the spider.
”People have been trying for years to express the spider gene in a different medium,” Gat says. “They tried everything plants, viruses but no system could make it possible spontaneous production of the fiber in sufficient quantities. We’ve now managed to do this.”
Gat and his team of researchers Israelis Shmuel Ittah and Shulamit Cohen, and Germans Dr. Thomas Scheibel, Daniel Huemmerich, and Fritz Vollrath have surmounted the obstacle. They decided to produce the protein within an insect with characteristics resembling those of spiders a type of caterpillar called the fall armyworm, which, like spiders, are arthropods. The fall armyworm itself produces fibers; it can be considered a kind of silkworm that produces spider web instead of silk.
”We took a virus known to infect the insect,” Gat explains. “From a laboratory that has investigated spiders for years, we obtained a gene known to produce the protein necessary for fiber production. We implanted the gene in the insect, and made sure that the virus would infect the insect cell. Then we saw that the fiber was created spontaneously within the cell. This is the first time that such fiber was created spontaneously in a laboratory.”
”Globes”: So you have neither a spider nor an insect in the laboratory only a jar.
Gat: ”Right. We have genes in the laboratory that are known to produce fiber, insects, and jars of insect cells. Now, in the next stage, we can go in two directions. One is to find a way to infect a living insect with this virus, and raise a farm of web spinning insects. Another possibility is to simulate in the laboratory the chemical environment of the inner cell, and produce the webs completely artificially.
”Each of these two methods has advantages. Production by insects is quick and efficient. With artificial production there isn’t any limit on the length of the fiber. Today, the length of the fiber is limited by the size of the cell. Under completely artificial conditions in the laboratory, however, we can produce fibers as long as we want.”
What can you use the fiber for?
“It seems that a spider web is the strongest fiber in creation. You can do many things with it; all you need is a good imagination. It is possible to produce bulletproof vests, fireproof suits, and protective clothing for extreme temperatures.
”In addition, the fiber is also very thin. The sub-fibers of which every web is composed are five nanometers thick. If we succeed in unraveling the web, we’ll be able to use the fiber in the semiconductor industry. If the fiber is coated with metal, it can be a conductor.
”In the medical industry, the fiber can be used for surgical thread, because it is very strong, and is made of biological material, and can therefore decompose.”
How is such a strong fiber created?
”Just like we see it in the laboratory. The principle is that the special proteins that make up the web are linked to each other, and create very tough surfaces. Between the proteins, however, there are very flexible and elastic areas, which make the thread elastic, and keep it from breaking.”
Are you planning to commercialize the invention?
”An investor whose name I can’t disclose has already approached us. Money has to be raised for the purpose, but that’s not my department.”
Won’t you try to be part of such a company?
”No. I’m a scientist, and I plan to remain a scientist. I do research on hair. I investigate hair follicles the protein from which hair is made. That’s how I got to the insects that create the proteins.
”I did post doctorate work at the University of Chicago, and Scheibel was in a nearby laboratory. He does research on amiloids, and is an expert on fibers in general. When we met, we got idea of creating a spider web within an anthropod. In cooperation, our two laboratories succeeded in implementing the idea.
”My aspiration is to combine web and hair research, which could help us produce a thread with the durability of hair and the strength of a spider web.”
Published by Globes [online] - www.globes.co.il - on December 6, 2004