No one doubts the astonishing properties of spider silk: it is both extremely strong and resilient – think a kind of rubbery-steel. But, despite decades of research, the secret of these properties has remained hidden within the spider. This was highlighted by a sad (or hilarious, depending on your viewpoint) episode in 2002. Newspaper headlines splashed that industrial quantities of spider silk were going to be manufactured by genetically engineered goats. The Canadian start-up behind this, though, soon found that, although it was possible to engineer goats that could express spider silk in their milk, the resulting fibre was not a patch on the real thing. It turned out that it wasn’t just the raw spider protein that did the trick but the way that the spider spins it.
In the years since 2002 chastened silk researchers have lowered their sights somewhat but now their work is starting to pay off. In 2014 I had another look at spider silk in the book I co-wrote with Tom Grimsey, Nanoscience: Giants of the Infinitesimal. The frontrunners in silk research at this point seemed to be the team at Tufts University, Boston, USA, led by David Kaplan and Fiorenzo Omenetto. They are developing advanced optical applications of spider silk.
But now, a blast from the past. For The Gecko’s Foot I interviewed Dr David Knight of Oxford University who had founded a spin-off to develop spider silk. That company, now known an Oxford Biomaterials, has refined the spinning of silk derived from silkworms to match the properties of spider silk and now the material is now ready for commercial exploitation.
The material developed by Oxford Biomaterials’ sister company Orthox, uses the processed silk for cartilage-like implants as an alternative to the knee replacement operations that are mushrooming with the ageing population.
The new material, known as FibroFix, not only replaces abraded cartilage, it allows regeneration. Clinical trials will begin soon and then we will know if the future is going to belong to silken knees.
The story demonstrates how long it can take for revolutionary science to become a practical proposition. It is a pleasure to see the nature-inspired technologies trailed in The Gecko’s Foot gradually taking their place in the everyday human world.