Bombyx mori spinning/OU
Researchers at the Oxford University have shown that it is possible to reel hundreds of metres of silk under full control, which is likely to have important implications for the large-scale reeling of silkworms for industrial production.
Professor Fritz Vollrath and colleagues from the Oxford Silk Group at Oxford University’s Department of Zoology collected silk directly from paralyzed silkworms by injecting a chemical that is naturally produced by the animal, according to a press release.
They have done this by harnessing the natural defence mechanism of silkworms, which causes paralysis, taking a step forward towards the large-scale production of silks with tailor-made properties.
In the wild, silkworms produce this hormone when they are injured since, as they move their bodies through hydrostatic pressure, without this self-induced paralysis their wounds would get worse and they would risk ‘bleeding out’.
The team of researchers has published their report entitled “The forced reeling of Bombyx mori silk: separating behaviour and processing conditions” in the latest ‘Biomacromolecules’ journal.
The report concludes that in comparison to unparalyzed silkworms, paralysis allows longer and more consistent silks to be collected by eliminating the ability of the silkworm to break and alter its silk fibre.
Although the direct ‘forced reeling’ of silk has been used in spiders for many years, reeling large amounts of silk directly from silkworms has not previously been possible. By tricking the silkworm into performing its natural response to injury and becoming paralyzed, the Oxford scientists show that it is possible to reel hundreds of meters of silk under full control, says the press release.
Unlike unravelling cocoons, as in the silk textile industry, silkworm forced reeling allows the silk properties to be modified to suit particular purposes. This has important implications for the large-scale reeling of silkworms for industrial production of environmentally-friendly fibres for use in a range of applications – from biomedical implants through to super-tough composite panels.
Silkworm paralysis may open the door to a range of silk technologies, using these animals which, unlike spiders, can be farmed at high-densities. Reeling of silk from paralyzed worms is the subject of a recent patent, which also highlights the exciting potential for genetically modifying silkworms to induce paralysis ‘on-demand’, a particularly useful feature for mass-rearing.
“This is an interesting result as the paralysis prevents the silkworms breaking the fibre, but still allows silk spinning and collection,” said Beth Mortimer of the Oxford Silk Group, an author of the report.
“The commercial implications of this process are self evident: now we can make silks to order by manipulating the mechanical properties while at the same time adding functionality,” said Professor Vollrath.