Scientists as Notre Dame University say this stronger silk has mechanical properties that could be used to make sutures, artificial limbs and parachutes.
The project to create transgenic silkworms with both silkworm and spider silk proteins was a collaboration between Notre Dame and the University of Wyoming.
"It's something nobody has done before," Malcolm Fraser Jr., Notre Dame professor of biological sciences, said in a university release Friday.
Fibers produced by the genetically modified worms were tougher than typical silkworm silk and as tough as dragline silk fibers produced by spiders, researchers said.
Commercial production of spider silk from spiders is impractical because spiders are too cannibalistic and territorial for farming, scientists say.
The stronger fiber from the modified silkworms 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, Notre Dame said.