Researchers have said that transgenically-engineered silkworms produce stronger silk, which could possibly be used to make sutures, artificial limbs and parachutes.
The silk that exhibits the highly sought-after strength and elasticity of spider silk was produced in the laboratory of Malcolm Fraser, Jr., professor of biological sciences at University of Notre Dame.
"It's something nobody has done before," Fraser said.
The project, which used Fraser's piggyBac vectors to create transgenic silkworms with both silkworm and spider silk proteins, was a collaboration of his laboratory with Donald Jarvis and Randolph Lewis at the University of Wyoming.
Jarvis's lab made the transgene plasmids, while Fraser's lab made the transgenic silkworms and Lewis's lab analysed the fiber from the silkworms.
Results showed that the fibers were tougher than typical silkworm silk and as tough as dragline silk fibers produced by spiders, demonstrating that silkworms can be engineered to produce such improved fibers.
Commercial production of spider silk from spiders is impractical because spiders are too cannibalistic and territorial for farming. Researchers have experimented with producing the stronger material in other organisms, including bacteria, insects, mammals and plants, but those proteins require mechanical spinning - a task the silkworms perform naturally.
The stronger fiber could find application in sutures, where some natural silkworm silk is used, as well as wound dressings, artificial ligaments, tendons, tissue scaffolds, microcapsules, cosmetics and textiles.
The findings were published in the Proceedings of the National Academy of Sciences.