Researchers at Karolinska Institutet and Suzhou University in China have achieved a breakthrough in creating strong, environmentally friendly spider silk fibers. They used silk proteins, with a type of molecular reinforcements called “spacer domains” Previous attempts to produce spider silk generated toxic feedstocks, resulting from spider silk proteins being introduced into other proteins.
The silk produced in the laboratory was not as strong as spider silk, which occurs naturally, and the spiders still had a "craftsmanship secret"