Washington: According to a new study cross silkworms produce fibers tougher than typical silk and as strong as dragline fibers produced by spiders, which could help make better sutures, artificial limbs and parachutes possible.

'It's something nobody has done before,' says Malcolm Fraser, professor of biological sciences at the University of Notre Dame, who led the study. 

The project, which used Fraser's piggyback vectors to create genetically engineered silkworms with both silkworm and spider silk proteins, was a collaboration of his lab with Donald Jarvis and Randolph Lewis, University of Wyoming.

Jarvis's lab made the transgenic plasmids, while Fraser's lab made the transgenic silkworms and Lewis's lab analyzed the fiber from the silkworms. 

Commercial production of silk from spiders is impractical because they are too cannibalistic and territorial for farming, according to a Notre Dame statement. 

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. This work is the culmination of a research effort begun more than 10 years ago with an internal award from the University of Notre Dame to Fraser to develop silkworm transgenic capabilities.