For the first time, a team of Chinese scientists has managed to enable genetically modified silkworms to make spider silk thread, which is also six times stronger than silk. 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 manufacture 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, “large-scale, low-cost commercialization” will be possible. Synthetic fibers, which release microplastics to the environment, they are usually produced from fossil fuels that generate greenhouse gas emissions, therefore, which makes 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 struggled to apply to the silk a surface layer of glycoproteins and lipids that help it resist moisture and exposure to sunlight, an anti-aging “skin layer” that spiders apply to their webs.
Genetically modified silkworms offer a solution to this problem, because They coat their own fibers with a similar protective layer.“Spider silk is a strategic resource that urgently needs to be explored,” said 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 surgical suture, meeting a global demand that exceeds 300 million annual interventions,” Mi emphasizes. 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.
To weave spider silk from silkworms, Mi and his team used gene editing technology CRISPR-Cas9 and hundreds of thousands of microinjections into fertilized silkworm eggs to modify the worms’ DNA and introduce spider genes. Although microinjections posed “one of the biggest challenges” of the study, the team knew the gene editing had been successful when they observed the silkworms’ eyes glowing red under the fluorescence microscope. The researchers also needed to make modifications of “localization” 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 silk from the silkworm. This concept of “localization” represents a significant change with respect to previous research, which is why we trust that large-scale commercialization is on the horizon,” concludes the researcher.