Photo by CRhyne via Flickr CC
Scientists have been investigating how to mimic spider silk for years. The seemingly delicate threads actually have a tensile strength five times greater than steel, and the possibilities for using a similar material in everything from buildings to bridges to cars and even clothing, are practically infinite. The only problem is, the stuff seems to be impossible to replicate. However, researchers have uncovered a key aspect in how spiders make silk, and they may be one step closer to man-made spider silk.
According to Science Daily, scientists from the Technische Universitaet Muenchen and the University of Bayreuth have solved the question of how spiders form long, stable, elastic fibers from the proteins stored in their silk glands in seconds. The spider silk is comprised of protein chains linked with stable physical connections, and between these are unlinked areas that contribute to the elasticity - making the silk both strong and flexible. But the mystery behind the molecules are what allows them to be stored in close confinement inside the silk gland without linking up and clumping. The scientists were able to figure out the structure of a control element used in the formation of the spider silk, and now they may be able to soon replicate the way spiders form silk.
"Under storage conditions in the silk gland these control domains are connected pair-wise in such a way that the interlinking areas of both chains can not lie parallel to each other," Thomas Scheibel explains. "Interlinking is thus effectively prevented." The protein chains are stored with the polar areas on the outside and the hydrophobic parts of the chain on the inside, ensuring good solubility in the aqueous environment.
"Our results have shown that the molecular switch we discovered at the C-terminal end of the protein chain is decisive, both for safe storage and for the fiber formation process," says Franz Hagn.
The scientists are well on their way to putting their findings to the test. They've developed an artificial spinning duct using microsystem technology, and are also working to develop a biomimetic spinning apparatus. The whole system will mimic a spider's silk gland and spinnerets, so now it's a matter of getting the formula perfected.
We're that much closer to having a material not only stronger than steel, but also usable in practically every setting - even as surgical sutures!