They innovate with silkworms as an alternative to synthetic fibers

A team of chinese scientists has achieved for the first time that some worms genetically modified silk fibers make spider silk thread, which is also six times more resistant than Kevlar, the synthetic fiber used to make bulletproof vests.

The study, published this Wednesday in the journal Matter, is the first to demonstrate a technique that could be used to make an ecological alternative to commercial synthetic fibers such as nylon.

Currently, worm silk is the only animal silk fiber commercialized on a large scale. According to the authors, thanks to these genetically modified silkworms, it will be possible “large-scale, low-cost marketing.”

Synthetic fibers, which release microplastics into the environment, are typically produced from fossil fuels that generate greenhouse gas emissions, making spider silk an attractive and sustainable alternative.

But copying nature is not without difficulties. The processes developed so far to weave artificial spider silk have had difficulties in applying a surface layer of glycoproteins and lipids to the silk that help it resist humidity and exposure to sunlight, a “layer of skin” anti-aging that spiders apply to their webs.

Genetically modified silkworms pose a solution to this problem, because they cover their own fibers with a similar protective layer.

“Spider silk is a strategic resource that urgently needs to be explored”says Junpeng Mi, first author of the study and a medical engineer at Donghua University (China).

“The exceptionally high mechanical performance of the fibers produced in this study is very promising in this field. “This type of fiber can be used as a surgical suture, meeting a global demand that exceeds 300 million annual interventions,” underlines Mi.

Spider silk fibers could also be used to create more comfortable clothing and innovative types of bulletproof vests, and could have applications in smart materials, the military, aerospace technology and biomedical engineering, Mi explains.

Gene editing techniques

To weave spider silk from silkworms, Mi and his team used CRISPR-Cas9 gene editing technology and hundreds of thousands of microinjections into fertilized silkworm eggs to modify the worms’ DNA and introduce spider genes into it. .

Although microinjections raised “one of the most important challenges” After the study, the team knew that the gene editing had been successful when they observed that the silkworms’ eyes glowed red under the fluorescence microscope.

The researchers also needed to make modifications to “location” in the proteins of the transgenic spider silk so that they would interact properly with the proteins in the silkworm glands and ensure that the fiber was spun correctly.

To do this, the team developed a “minimal basic structure model” of silkworm silk.

That concept of “localization” represents a significant change from previous research, which is why we are confident that large-scale commercialization is on the horizon,” concludes the researcher.

Source: EFE