Spider silk is prized for its unrivaled strength and toughness. But figuring out a way to mass-produce it is no easy feat. Spiders cannot be put to work to pump out the fibers the way silkworms can: They’re extremely territorial and inclined to eat their neighbors, and they refuse to keep at the task for long. So for decades, scientists have tried to genetically-engineer various organisms — including bacteria, yeast, mice, hamsters and even goats — to produce spider silk, but with only partial success.
Now, for the first time, researchers from China have coaxed pure spider silk out of genetically modified silkworms. The material is six times as tough as the Kevlar used in bulletproof vests, the team reports in the Oct. 4 Matter.
The fibers flaunt “better mechanical properties than anybody else has been able to show,” says molecular biologist Randy Lewis, a spider silk expert at Utah State University in Logan who wasn’t involved with the study.
The strands are not as strong or as stretchy as natural spider silk, but they are an advance (SN: 11/7/08). Previous work in silkworms generated weaker fiber blends of only 30 to 50 percent spider silk.
In the new study, the researchers used the gene-editing tool CRISPR/Cas9 to insert the complete instructions for making spider silk protein into silkworms and make sure the protein wound up in the silkworms’ silk-making glands. That allowed the team to take advantage of the insect’s natural machinery. Breeding the tweaked silkworms then resulted in some that inherited the spider silk gene from both parents, meaning they could produce purer spider silk.
If the silk someday makes it out of the laboratory, doctors could use it to sew extra-sturdy sutures. Police officers could don stronger armored vests. And a more environmentally friendly fiber could replace common synthetics like nylon and polyester.
“Spider silk stands as a strategic resource in urgent need of exploration,” Junpeng…
Read the full article here