Invention: Artificial spider silk
Over 300 million years of evolution have produced one of the world's strongest materials – the silk fibres of a spider web. Now, thanks to German biochemist Thomas Scheibel, it is finally possible to mass-produce spider silk as a next-generation industrial fibre. The development of an industrial-scale manufacturing process for bioengineered spider silk, marketed by German start-up AMSilk, unlocks new possibilities in textiles, cosmetics and medicine.
Spider webs are among nature's most resilient structures. Lightweight
and almost invisible, they can stretch up to 140 per cent in length
without breaking thanks to the incredible strength of spider silk. In fact, spider silk is five times stronger
than steel and three times stronger than the Kevlar in bulletproof vests.
Scientists and chemical companies had not been able to mass-produce spider silk. Unlike silkworms, which produce their silk in large quantities, spiders produce only small amounts of their robust thread. Plus, spiders cannot be raised on silk farms due to their cannibalistic and territorial behaviour.
In order to solve the problem, Scheibel decided to take spiders out of the equation: his patented process relies on E. coli bacteria that are genetically reprogrammed to produce spider silk proteins. This raw material is then "spun" into ultra-strength spider silk fibre in a complex mechanical process that took years to perfect.
Brought to market by Munich-based start-up AMSilk in 2014, Scheibel's spider silk is available in industrial quantities, with applications ranging from biotolerable medical implants and lightweight sports shoes to breathable nail polish.
Societal benefit
The invention makes a new "supermaterial" available on a mass scale. Spider silk can withstand pressure of 4.5 gigapascals (GPa), far surpassing bamboo (1 GPa), human teeth (0.5 GPa) and wood (0.3 GPa). Moreover, a strand of spider silk long enough to wrap around the Earth would weigh less than a bar of soap. Biocompatible with a low risk of rejection, it is used to coat medical implants.
Scheibel's process is entirely animal-free. Regular silk is "harvested" from silkworm cocoons. Other approaches to producing spider silk still rely on animals, such as transgenic silkworms that spin cocoons containing spider silk, or genetically engineered goats that produce silk proteins in their milk.
Economic benefit
In order to use his patented process on an industrial scale, in 2008 Scheibel co-founded AMSilk - a spin-off company from the Technical University of Munich (TUM) that is headquartered in Planegg-Martinsried just outside Munich. The majority shareholder is AT Newtec GmbH; the TUM is a minority shareholder. So far the company has raised millions in venture capital, and employs 30 people.
AMSilk sells purified silk protein ingredients in three product lines: first, cosmetic products including breathable Silkgels and controlled-release Silkbead capsules for gels and creams, etc.; second, medical applications such as coatings for medical implants; and finally, a biodegradable performance fibre called Biosteel, which is about 15% lighter than conventional synthetic fibres.
In spring 2017, AMSilk launched a water-based, breathable nail polish, marketed through its licensee Ocean Pharma. A year earlier, Adidas created a concept sports shoe using Biosteel. Spider-silk-coated implants are currently undergoing clinical trials in Europe with Polytech.
Scheibel's synthetic fibres are having an impact on the global market for biopolymers, which generated over EUR 5.6 billion in revenues in 2015, with Europe responsible for 39% of sales - mostly of bioplastic packaging. The invention could also make inroads into the world market for traditional silks, projected to reach almost EUR 14 billion by 2021.
