Making a silk purse out of a goat’s milk

A UK company is developing technology to spin silk like spiders’ webs for industrial, medical and domestic applications.

The process emulates the way arachnids spin webs and silkworms produce cocoons. It will provide a simpler method of manufacturing new lighter, tougher fabrics designed init-ially for specialist clothing and medical products.

Winchester-based Spinox is an Oxford University company founded by Dr. David Knight: ‘Industry has traditionally used high pressures and high temperatures to process silk. But our method is like that of a spider. We looked closely at how they spin and the principle is totally different. They can’t use high pressures or high temperatures.’

Instead, spiders align tightly packed and folded rod-shaped molecules. The material acts like a liquid crystalline system, which means its molecules can be pointed in the same direction. The rods form long chains, sticking to each other end to end, giving the silk its strength.

Spider’s silk is one of the strongest lightweight materials known, but it has proved difficult to manufacture on a large scale.

So far, Knight has tested his spinning method with silk taken from the bodies of spiders. But the company aims to test the process with spider silk that has been artificially produced by genetically modified goats.

Nexia Biotechnologies, a Canadian company, has inserted spider’s genes into the DNA of goats to successfully produce large quantities of the silkproteins in the animals’ milk.

‘After testing with real silk we will know, with the Canadian silk, that if it doesn’t work it’s because their material is wrong rather than our spinning,’ said Knight. But he admitted the spinning process still needs to be optimised. At the moment only centimetres of material can be spun. For industrial purposes that needs to be improved.

Knight said Spinox should have a technology ready to license for manufacture by 2005.