The new Silk Road starts with goat udders
Forget the catwalk. To see this season's most impressive silks, head for the barnyard.
Last month, silk fans got their best news in a couple of millennia when the journal Science published findings indicating that goats may soon be producing spider silk. The discovery, a joint venture of Montreal-based Nexia Biotechnologies and a US Army research lab in Natick, Mass., has for years been described as a "holy grail" of materials science.
Spider silk, developed through 400 million years of evolution, is light and flexible, and has at least five times the tensile strength of steel. For the past century, scientists have tried to reproduce its strength and elasticity synthetically, with little success. Artificial "silks," like polyester, proved poor substitutes.
Efforts to farm spiders and harvest their silk were also futile - something that's no surprise to those who have spent quality time with the reclusive arachnids. "Spiders eat other spiders," explains Russ Smith, curator of reptiles at
the Los Angeles Zoo, and a dabbler in spiders. Small male spiders live in particular peril, often doubling as lunch for over-amorous mates.
Scientists thus turned to "biomimicry," developing new technology based on models and designs in nature. They extracted silkmaking genes from two spiders and implanted them in cells from a cow's udder and a hamster's kidney. Those cells secreted protein chains that formed a crystalline silk filament like the one with which Charlotte, in the only other documented instance of such arachnid-farm animal cooperation, once famously scrawled "Some Pig."
The material they produced is strong enough to be used as sutures in delicate surgery. The team's next goal is to strengthen the manmade silk so that it can be used to weave bulletproof body armor. To produce enough protein for that, scientists have implanted the silk gene in the eggs of nanny goats, so that their female offspring will secrete the protein in their udders. "All we'll have to do is milk the goats," says Nexia President and CEO Jeffrey Turner.
Simple enough - sort of. Maria Tulokas, head of the textile department at the Rhode Island School of Design in Providence, wonders how this goat wrinkle might affect another important issue: silk's mystique.
Until now, spider silk has never been used to make cloth. Those "incredibly sumptuous, beautiful old fabrics" made in China since about 2700 BC, and elsewhere, are woven from strands of fiber spun by silkworms. Still, spiders have always been bound up in silk's mythology. "The whole process of [spider and silkworm] silk production is quite miraculous," Ms. Tulokas says.
For many, turning goat's milk into silk seems at least as incredible. Brent Karner, insect zoo coordinator at the Natural History Museum of Los Angeles, is thrilled with the advance in silk technology - not least because it may give the much-maligned spider an image boost. The implications of the discovery for the future of goat cheese, though, remain to be seen.
Material from wire sources was used in this report.