A device that recreates the conditions in spiders' silk-spinning apparatus has produced 1,000 metres of material that is tougher than other spun artificial spider silks.
Anna Rising and Jan Johansson at the Swedish University of Agricultural Sciences in Uppsala and their colleagues used the bacterium Escherichia coli to make a water-soluble protein containing domains from the silks of two species of spider, Euprosthenops australis and Araneus ventricosus. The team then pumped the protein solution through a glass capillary into an acidic bath, mimicking the conditions experienced by natural silk as it passes down through a spider's silk glands and silk ducts. The result was continuous fibres with a diameter of 10–20 micrometres.
The artificial silk (pictured) had some physical properties that were similar to those of natural silk, but was less tough.
Nature Chem. Biol. http://dx.doi.org/10.1038/nchembio.2269 (2017)