Inspired by Nature: Bio-Mimicked Spider Silk

Bio-based and bioengineered materials are being used in textiles, cosmetics, and packaging to replace traditional synthetics with less toxic alternatives. Spider silk is a protein fiber spun by spiders, which has high tensile strength, making it a desirable material for a variety of applications. However, spiders cannot be farmed because they are cannibalistic. Enter bio-mimicked spider silk, which is commonly made using bioengineered bacteria, yeast, or silkworms and displays performance characteristics similar to those found in nylon and polyester. Bio-mimicked silk fibers can replace plastics in biomedical fields and personal care, with applications such as drug delivery, tissue repair and regeneration, skincare, and haircare. The same material is also used in biodegradable food packaging, which has been strongly supported by upcoming regulation pressure to limit plastic packaging, waste, and disposables in the EU.

These solutions offer several environmental benefits over traditional synthetic textiles and plastics, including:

  • Ability to biodegrade without the harmful impacts of microplastics
  • Production without the use of oil or hazardous chemicals
  • Protein inputs are sourced sustainably from plants, bacteria, silkworms, goats, and yeast
  • Less energy intensive when compared to production of synthetics

Attractiveness

The global synthetic spider silk market is expected to reach $19.8 billion in 2026, with a CAGR of 16.7% between 2021-2026. The Material Innovation Initiative (MII) believes that next-generation materials will reach 3% of the $70 billion global wholesale materials market by 2026.

The synthetic spider silk market is thriving as consumer demand grows for sustainable alternatives to toxic chemicals. The European Union was the largest exporter of chemical products in 2019, providing a promising market for innovators looking to scale up production, but currently the US is leading the growth of synthetic spider silk. Companies in the US are using spider silk’s strength to their advantage by partnering with government organizations and using the material in military applications, such as bulletproof vests.

Business models vary according to production method

As mentioned above, spider silk’s high tensile strength makes it suitable for use in military and medical fields. Innovators in this market are producing spider silk ‘synthetically,’ through genetic modification of proteins in living hosts, then using that bio-engineered protein to spin fibers. Innovators have adopted different approaches to producing bio-mimicked spider silk:

Fermented Proteins

We spoke to Bolt Threads’ Chief Science Officer, David Breslauer, who explained the importance of shifting the apparel and personal care industries away from animals and plastics, and towards next generation materials grown from and inspired by nature. Bolt develops proteins inspired by natural spider silk using bioengineered yeast. Yeast, sugar, and water are used as inputs to the fermentation process with silk proteins then isolated and spun into fiber. The company recently partnered with Ginkgo Bioworks to leverage their expertise in strain engineering to improve the sustainability, efficiency and cost effectiveness of Bolt’s b-silk protein.

AMSilk uses a plant-based raw material and bacterial fermentation to produce silk proteins that can be used with existing textile manufacturing equipment for textile applications or incorporated into medical devices and products. AMSilk received $35 million in growth equity from Novo Holdings, Cargill, ER Capital Holdings, MIG Verwaltungs and Athos Capital in May of this year. The funding will be used to accelerate the ongoing scale-up of AMSilk’s industrial projects worldwide and further the internationalization of its commercial activities.

Spiber starts with plant-derived biomass and uses a fermentation process to create their protein materials, which can be processed into a variety of forms, from filament fibers to spun yarns with properties similar to cashmere and wool. Spiber has raised $606.7 million in funding in the past year alone from investors such as the Carlyle Group, Mitsubishi UFJ Lease & Finance, and Archer Daniels Midland.

Silkworms

Evolved by Natures Activated Silk Technology is made from natural silk protein and water, harvested from silkworm cocoons. Their technology platform creates versatile silk molecules that can replace petrochemicals and introduce performance benefits in textile, medical, and personal care products. In 2019, luxury fashion brand Chanel invested a minority stake in Evolved by Nature.

Kraig Biocraft Labs uses spider silk gene sequences in silkworms to create their genetically engineered spider silk, which is significantly stronger and more flexible than commercial grade silk. Their product is aimed at technical textiles as well as consumer-focused silk and apparel markets. Kraig received $5 million in post-IPO financing over the past couple years from undisclosed investors for the commercialization and sale of their recombinant spider silk.

Controlled Self-Assembly

Cleantech Group spoke to Xampla’s CEO, Simon Hombersley, who explained their focus on decentralized production and how crucial biodegradability is to their products, “Next generation bio-based materials need to be sustainably sourced and have perfect end of life, with no negative harmful outputs.” Many companies have created chaos with false claims and greenwashing in the sector but having strong biodegradability properties is of high importance at Xampla. Their innovation technology is inspired by the way that spiders can control protein self-assembly. By taking plant protein, breaking the protein structure, and controlling the self-assembly of it through a bio mimetic process, they can create a plant-based, fully biodegradable replacement to plastic. Xampla received $8.3 million in seed funding earlier this year from Horizon Ventures to accelerate the roll out of their next-gen plastic replacement.

Seevix uses a similar process of bio-mimicking spider silk’s self-assembled nanostructures, but they use spider silk proteins to create the nanofibers that can be used in medical applications, cosmetics, and composite materials. Japanese sportswear company ASICS, invested in and partnered with Seevix to jointly develop sporting goods using Seevix’s SVX Spidersilk.

Another innovator, Spintex, is using spinning machines in tandem with their feedstock to allow self-assembly into fiber. Their feedstock can transform from a liquid to a solid just from physical force without the use of bioreactors, resulting in high energy savings. Spintex received a grant from the Creative Destruction Lab in January.

Goats

Inspidere makes their silk product by genetically engineering goats to produce a spider protein in their milk, which can be purified and then spun into fibers. They are targeting the apparel and automotive industries, but their silk-based composite can be incorporated into a wide range of products, such as body armor, workwear, sports apparel, and premium interior applications.

Competition

Companies in this space are looking for partners to scale up production, as exemplified by Spiber’s recent channel partner, Archer Daniels Midland. ADM will produce Spiber’s Brewed Protein polymers in the US using plant-based dextrose as feedstock. The polymers will then be shipped to Spiber’s downstream facilities to be processed into a variety of materials for applications such as apparel, auto parts, and high-performance foams.

Licensing agreements and commercial partnerships with fashion and apparel brands have also allowed innovators to enter new markets and expand globally. Spiber collaborated with designer Yuima Nakazato and Japanese luxury brand Sacai to launch collections featuring their protein materials. Kraig Biocraft Labs formed a joint venture with MtheMovement in January of this year, called SpydaSilk, which will develop and sell Kraig’s spider silk fibers under a new apparel and fashion brand. Under the agreement, SpydaSilk will have an exclusive geographic license to all of Kraig’s technologies for the ASEAN region, in exchange for a four-year commitment to purchase up to $40 million of Kraig’s spider silk product. Innovator Bolt Threads formed a consortium with Stella McCartney, Kering, Lululemon and Adidas late last year to explore the use of their spider silk and mycelium leather substitute in the brands products. Evolved by Nature has also seen their activated silk technology incorporated into the garments of sustainable activewear brand, Gentrue.

Keep an eye out for…

For bio-mimicked spider silk innovators looking to compete in apparel markets, the biggest challenge will be to break through the cost structure that this long-standing industry has built around polyester. Polyester is cheap and widely available. It will be difficult for biotech innovation to compete without regulatory pressure on brands to change their production practices. Fortunately, regulation in the EU against microplastics and single-use plastics looks promising to change the synthetics industry for the better.

One innovator to watch out for is Protein Materials, which is using DNA from spiders to bioengineer recombinant silk proteins. Protein Materials has partnered with the Department of Defense to industrially manufacture spider silk that has met the U.S. Army’s requirements for strength and elasticity. The company claims to be able to reduce production cost by 54%, making their bioengineered silk cheaper than wool and traditional silk when produced at scale. Protein Materials has signed agreements with another major apparel company, the name of which has not been disclosed.

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