Scientists have genetically modified silkworms to produce a sustainable spider silk six times stronger than a bulletproof vest.
The researchers from China used microinjections and gene editing technology in silkworms to produce an exciting new material – which could provide an environmentally-friendly alternative to synthetic fibers such as nylon.
The silk is said to be around six times stronger than Kevlar – an extremely strong material used to make bulletproof vests – and could have applications in industries ranging from textiles to aerospace technology and biomedical engineering.
The study, published in the journal Matter, is the first to ever successfully produce full-length spider silk proteins using silkworms.
Scientists have long earmarked spider silk as an enticingly sustainable alternative to synthetic fibers.
The manufacture of such fibers can release harmful microplastics into the environment and are often produced using fossil fuels.
However, turning to the natural world for assistance is an approach fraught with its own challenges.
Previous efforts to produce artificial spider silk have struggled to apply a surface layer of “anti-aging” skin layers of glycoproteins and lipids to the silk, which help the material withstand humidity and exposure to sunlight.
Junpeng Mi, a doctoral candidate at the College of Biological Science and Medical Engineering at Donghua University in Shanghai, China, and the first author of the study, sought assistance from silkworms to find a solution to this problem.
Mi and his team introduced spider silk protein genes into the DNA of silkworms using a combination of CRISPR-Cas9 gene editing technology and hundreds of thousands of microinjections into fertilized silkworm eggs.
These microinjections posed one of the most significant challenges in the study, Mi explained.
But, when he saw the silkworms’ eyes glowing red under the fluorescence microscope – a telltale sign that the gene editing had been successful – he was overjoyed.
“I danced and practically ran to Professor Meng Qing’s office to share this result,” Mi said.
“I remember that night vividly, as the excitement kept me awake.
“Silkworm silk is presently the only animal silk fiber commercialized on a large scale, with well-established rearing techniques.
“Consequently, employing genetically modified silkworms to produce spider silk fiber enables low-cost, large-scale commercialization.
“Spider silk stands as a strategic resource in urgent need of exploration.
“The exceptionally high mechanical performance of the fibers produced in this study holds significant promise in this field.
“This type of fiber can be utilized as surgical sutures, addressing a global demand exceeding 300 million procedures annually.”
Mi added that the spider silk fibers could be used to create more comfortable garments and innovative types of bulletproof vests, and may even have wider applications in smart materials, military and aerospace technology and biomedical engineering.
The researchers also had to perform “localization” modifications on the spider silk proteins so they would interact properly with proteins in the silkworm glands and ensure the fiber was spun properly.
To guide the modifications, the team developed a “minimal basic structure model” of silkworm silk.
“This concept of “localization,” along with the proposed minimal structural model, represents a significant departure from previous research,” Mi explained.
“We are confident that large-scale commercialization is on the horizon.”
Mi and his team plan to use insights into the toughness and strength of their newly engineered spider silk fibers to develop genetically modified silkworms that produce spider silk fibers from both natural and engineered amino acids in the coming years.
Mi added: “The introduction of over one hundred engineered amino acids holds boundless potential for engineered spider silk fibers.”
Produced in association with SWNS Talker
