Spinning stronger synthetic spider silk

A new method for producing stronger artificial spider silk is reported in a study published online this week in Nature Chemical Biology. Spider silk is an attractive biodegradable material for many different applications, but producing artificial silk with the same properties as natural silk has historically been difficult.

Spider silk is made up of long chains of linked protein molecules. Inside silk glands, the proteins used to make the silk are kept in a very concentrated solution. When spinning silk, the spider secretes the protein solution through a narrow duct. Along the length of this duct, the acidity changes and the pressure increases, causing the protein molecules to link up in the chains that form the silk fiber.

Inspired by the way that spiders spin silk, Jan Johansson, Anna Rising and colleagues designed a spinning device that mimics the narrow duct and acidity changes met by silk protein in spider glands. Using this device on a special protein - a hybrid of two natural silk proteins that can be manufactured in a highly concentrated form - enabled the authors to produce artificial spider silk that has greater strength and elasticity than other artificial silks, and that is nearly as strong as natural spider silk.

The authors note that the biodegradable silk produced by this method is cheaper and easier to obtain than natural spider silk, and will potentially allow for the production of large amounts of silk for applications such as high-performance textiles and advanced medical devices.