Spider silk is spun by silkworms for the first time, offering a green alternative to synthetic fibers

For the first time, silkworms spin spider silk, providing a more environmentally friendly option to synthetic fibers.

The research is the first to use silkworms to effectively synthesize full-length spider silk proteins, and it was published in the journal Matter on September 20. The results show how a method for producing a greener substitute for commercial synthetic fibers like nylon may be used.

"With well-established rearing techniques, silkworm silk is currently the only animal silk fiber commercialized on a large scale," stated Mi. Consequently, low-cost, large-scale commercialisation is made possible by using genetically engineered silkworms to generate spider silk fabric.

Spider silk has caught the attention of scientists as a very attractive and environmentally friendly substitute for synthetic fibers, which are frequently made from fossil fuels that emit greenhouse gases and have the potential to discharge hazardous microplastics into the environment. But there are drawbacks to looking to nature for solutions.

The application of a surface layer of glycoproteins and lipids to artificial spider silk, which provides an anti-aging "skin layer" similar to what spiders apply to their webs, has proven difficult in previous attempts to spin the silk.

According to Mi, the issue may be resolved by using genetically modified silkworms because they have a comparable protective covering on their own fibers.

A Ph.D. candidate at Donghua University's College of Biological Science and Medical Engineering, Junpeng Mi is the study's first author. "Spider silk stands as a strategic resource in urgent need of exploration," Mi stated.

"The fibers generated in this work have remarkably good mechanical performance, which indicates great promise in this sector. This kind of fiber may be used for surgical sutures, meeting a need that exceeds 300 million surgeries worldwide each year."

According to Mi, the spider silk strands may potentially find usage in smart materials, biomedical engineering, aerospace technology, and the military. They might also be utilized to make novel kinds of protective vests and more comfortable clothing.

In order to create spider silk from silkworms, Mi and his colleagues used a combination of CRISPR-Cas9 gene editing technology and hundreds of thousands of microinjections into fertilized silkworm eggs to insert spider silk protein genes into the DNA of the silkworms so that it would be produced in their glands.

A indication that the gene editing had been effective, Mi noted that the microinjections were "one of the most significant challenges" in the project. Nevertheless, he was ecstatic to see the silkworms' red flashing eyes under the fluorescence microscope.

In order to ensure that the fiber would be spun correctly, the researchers also had to carry out "localization" alterations on the transgenic spider silk proteins to enable optimal interaction with proteins in the silkworm glands. The group created a "minimal basic structure model" of silkworm silk to serve as a guide for the changes.

Mi states, "This thesis introduces a concept of 'localization,' along with the proposed minimal structural model, which represents a significant departure from previous research." "We have no doubt that widespread commercialization will soon occur."

Mi intends to create genetically modified silkworms that generate spider silk fibers from both natural and synthetic amino acids in the future. This will allow her to take advantage of the knowledge about the strength and toughness of spider silk fibers gained from the current work.

"There is endless potential for engineered spider silk fibers with the introduction of over one hundred engineered amino acids," claims Mi.