Researchers from Donghua University in China have turned gene-edited spider silk — fiber spun by spiders — into a fiber that is six times stronger than bulletproof Kevlar.

With mechanical properties such as flexibility and toughness, the Donghua team determined that spider silk could serve as an alternative to synthetic fibers like nylon which are derived from plastic. However, spider silk is reportedly hard to procure.

Source: Mi et al.

As such, the researchers opted to synthesize spider silk from genetically engineered silkworms to create a sustainable alternative for synthetic fibers.

“Silkworm silk is presently the only animal silk fiber commercialized on a large scale, with well-established rearing techniques,” explained the researchers. “Consequently, employing genetically modified silkworms to produce spider silk fiber enables low-cost, large-scale commercialization.”

To accomplish this, spider silk was combined with silkworms through a process known as localization wherein spider silk protein genes are introduced into the genetic material of silkworms.

Using CRISPR-Cas9 gene-editing technology as well as microinjections into fertilized silkworm eggs, localization was performed so that silkworm glands instead produced spider silk.

The team suggests that the silk fiber produced from this process exhibited high tensile strength and toughness, and they believe that the material could potentially be used as surgical sutures.

An article detailing the findings, “High-strength and ultra-tough whole spider silk fibers spun from transgenic silkworms, was published in the journal Matter.