Artificial spider silk breakthrough
Researchers reveal mass production technique for threads ‘stronger than steel’
A team of Swedish researchers have finally managed to produce artificial spider silk – and say it could soon be used in everything from bullet proof clothing to sutures as strong as steel.
Researchers have struggled to mass-produce the fibres, but now a team of researchers from the Swedish University of Agricultural Sciences and the Karolinska Institutet has developed a method that allows them to produce kilometer long threads of the material.
Spider silk is a material that has many advantages: It’s well tolerated when implanted in tissues for sutures, it’s light-weight but stronger than steel, it’s biodegradable and it has even been used to make violin strings.However, spiders are difficult to keep in captivity and they spin small amounts of silk, so being able to produce it at a large scale is a research breakthrough.
Any large-scale production of spider silk must involve the use of artificial silk proteins and spinning processes. The researchers used a biomimetic (that mimics nature) spinning process to manufacture fibers that are similar to real spider silk.
The research, published in the journal Nature Chemical Biology, also included videos and photos of the process. Spider silk is made of proteins that are stored as a water-based solution in a spiders silk glands, before being spun into a fiber.
Until now, it wasn’t possible to make artificial spider silk because of difficulties in obtaining similar watery spider silk proteins. But the researchers managed to develop a method using artificial proteins that can be produced in large quantities in bacteria.
“To our surprise, this artificial protein is as water soluble as the natural spider silk proteins, which means that it is possible to keep the proteins soluble at extreme concentrations,” said Dr. Anna Rising, one of the lead researchers of the study.
Rising and her colleagues previously found that there is an impressive pH gradient in the spider silk gland. pH refers to how acidic a substance is – the lower the pH, the more acidic something is.
This well-regulated pH gradient affects specific parts of the spider silk proteins and ensures that the fiber forms rapidly in a defined place of the silk production apparatus.
This knowledge has now been used to design an artificial spider silk protein that can be produced in large quantities in bacteria, which makes it possible to produce the silk at a large scale in an industrial setting.
To mimic the spider silk gland, the research team constructed a simple but very efficient spinning apparatus in which they can spin kilometer-long fibers only by lowering the pH.