A new spin on silk production

SMALLPRINT:SILK HAS LONG been a prized material for textiles, and can be used in surgery for sutures. Spider silk is a particularly desirable version: elastic yet strong and tough.

But spider silk is difficult to produce in large quantities: spiders don’t generally play ball in farming, because they can be territorial and eat each other.

On the other hand, silkworms are expert silk spinners and they are far more amenable to being cultivated en masse. So why not recruit silkworms instead to spin spider silk fibres?

That’s what researchers in the US set out to try through a genetic sleight of hand, by inserting DNA containing spider silk code into silkworms.

As a result, the silkworms produced silk that contained a small amount of spider silk woven through the fibres, and that was enough to improve the hybrid material’s physical properties.

The discovery was announced in 2010 by scientists from University of Notre Dame, the University of Wyoming and Kraig Biocraft Laboratories, and the scientific paper has just been published online in the Proceedings of the National Academy of Sciences.

“On average, the composite fibres produced by our transgenic silkworm lines were significantly tougher than those produced by the parental animals and as tough as a native dragline spider silk fibre,” they write.

“In best-case measurements, the composite fibre produced by one of our transgenic silkworms was even tougher than the native dragline spider silk fibre.”

Ultimately, the mechanical properties of spider silk fibres would be ideal for medical procedures requiring finer sutures, such as ocular, neurological and cosmetic surgeries, they note.