A brief history of silk
Silk in the past
Silk is the world’s oldest commercial fibre. It has been produced industrially for over 4 millennia through the domestication of an insect, the Chinese silkworm Bombyx mori, an animal whose protective cocoon has sparked conflict and founded empires. Yet this is just one of tens of thousands of silks produced by Nature. By looking at silk’s biodiversity we find that beyond an impressive material itself, silk can be more than just a fibre; provided we process it correctly.
Silk is a model biopolymer.
Silks are a group of structural proteins that have evolved independently many times in spiders, silkworms and even ants. However spiders have truly harnessed the power of silk, producing bespoke types that are used in all aspects of their lives, from foraging to reproduction.
Uncovering the biological significance of silk is key to understanding how Nature has evolved such an impressive and important material. We believe this will pave the way for us to imitate it biomimetically.
The Natural Materials Group includes scientists from many disciplines, biologists, chemists, physicists, engineers and medics, each bringing a unique perspective into silk. We are currently building a picture of how silk behaves in all stages of production, from the nanoscale structures of the proteins in solution, to the performance of the fibres within a cocoon.
Our work on unspun silk has shown that there are evolutionary constraints acting upon how silk flows. Excitingly though, these silks behave very much like molten polymers. This allows us to turn evolutionary constraints into design criteria for improving our own industrial fibres. In return this has opened the door for us to use tools and techniques originally developed for polymer science to study silk.
Silk is more than just a fibre.
By dissolving silk fibres using specially selected chemicals (termed ‘reconstitution’), it can be reprocessed into films, gels, powders and even sponges.
Already these silk-based materials are being developed for use in medicine. A series of companies ‘spun’ out of the Oxford Silk Group are developing sutures, tendon, cartilage, bone and even neural guides to repair damaged nerves.
However in order to create truly biomimetic silk fibres we must learn how to minimise the damage done to the silk proteins during reconstitution.
Silk may also contribute to helping us unravel one of the greatest challenges facing science; protein folding.
Silk spinning is a model example of highly controlled protein folding and aggregation. Understanding these processes will also shed light on related mis-folding events in amyloid based diseases such as Alzheimer’s and BSE. Back Next