Scientists reveal how black widow spiders create steel-strength fibers

WASHINGTON — Scientists have revealed how black widow spiders weave steelstrength silks, which could help create equally strong synthetic materials.

The study published on Monday in the Proceedings of the National Academy of Sciences journal showed that spider silk proteins did not start out as simple spherical micelles as previously thought, but instead as complex, compound micelles. Micelles are clusters of water soluble and non-soluble molecules.

This unique structure is potentially required to create the black widow spider’s impressive fibers, which might compare to steel when it comes to tensile strength, according to the study.

Previous research suggested that spider silk proteins await the spinning process as nano-size micelles before being funneled through the spider’s spinning apparatus to form silk fibers.

However, when scientists attempted to replicate this process, they were unable to create synthetic materials with the strength and properties of the spider’s silk fibers.

Researchers at Northwestern University and San Diego State University used nuclear magnetic resonance spectroscopy to see inside the protein gland where the silk fibers originate, revealing a much more complex, hierarchical protein assembly.

“We now know that black widow spider silks are spun from hierarchical nano-assemblies (200 to 500 nanometers in diameter) of proteins stored in the spider’s abdomen, rather than from a random solution of individual proteins or from simple spherical particles,” said the paper’s co-author Gregory Holland, associate professor in the department of chemistry and biochemistry at San Diego State University.

If duplicated, “the practical applications for a material like this are essentially limitless”, Holland said.

It could include high-performance textiles for military, first responders and athletes; building materials for cable bridges and other constructions; environmentally friendly replacements for plastics; and biomedical applications, according to the researchers.

GETTY IMAGES A black widow spider.