Skip to main content

Novel approaches to the generation of artificial spider silk superfibers

Periodic Reporting for period 2 - ARTSILK (Novel approaches to the generation of artificial spider silk superfibers)

Reporting period: 2020-11-01 to 2022-04-30

We will develop a novel high-performance biobased fiber. This will be accomplished by using state-of-the-art sequencing technologies and protein engineering to design novel proteins that is efficiently produced in bacteria and that can be spun into fibers by biomimetic spinning.

Due to humanity’s negative impact on climate and biodiversity on Earth, we must develop novel high-performance materials that can replace the petroleum based products that we use today. Furthermore, if we could mass-produce Nature’s toughest fiber – spider silk – we could potentially bring technology forward as a whole. Such a material would result in new green jobs and improvement of our environment and quality of life.

The overall objective of ARTSILK is to use state-of-the-art technologies to generate artificial silk fibers that are equal or superior to native spider silk in terms of toughness and tensile strength. We will achieve this by using information retrieed from the spider genome and from studies of the transcriptome of the silk gland (down to individual cell level). This information will make it possible to design an array of novel silk proteins that can be produced by bacteria, purified and spun into fibers using a spinning method that recapitulates the molecular mechanisms of spider silk spinning (i.e. it is biomimetic and void of harsh solvents and high temperatures).
So far we have managed to develop a production process that results in 10 times higher protein yields than has ever been achieved before and shown that we from a 1,6 liter culture can extract enough silk proteins to spin a 125 km long fiber. This opens up the possibility to commercialize artificial silk. The work was published by Schmuck et al in Materials Today in 2021, and received a lot of media attention. We have also managed to improve the properties of our fibers by determining the rheological properties of our spinning dope (Arndt et al. ACS Biomaterials Science and Engineering 2021) and by making changes to the spinning device (Gonska et al. Biomacromolecules. 2020; Greco et al. Communications materials. 2021).

Ongoing work:
We have established a protocol for doing single cell RNA sequencing of the spider silk gland and we are currently analyzing the data from 20 individual spiders.
By using rational protein engineering and insights into basic biology we have designed an array of proteins that should result in stronger fibers. These have been spun and be have identified two proteins that outperform the currently best fiber produced. This work is being put together in a manuscript.
The spider's genome has been sequenced and we have used this information to identify a battery of different protein sequences of interest. These have been produced and purified and spun into fibers. We have obtained some surprising results that we are currently protecting by submitting a patent application. The work will thereafter be published in a scientific journal.
We have also improved the spinning apparatus by screening the impact of several conditions (buffer composition, reeling speed, etc) and this work is now being finalized.By optimizing these conditions we have improved the properties of our fibers further.
We have established a production process and a spinning device that make it realistic to bring artificial spider silk fibers to the market. These fibers are produced in a biomimetic process that is void of harmful chemicals, and are tougher than nylon and kevlar.
By empoying a strategy that the spiders cannot use we have shown that it is possible to produce artificial spider silk fibers with the same toughness as native spider silk. These proteins can be produced at high yields and are spun into fibers in a process that only involves ambient temperatures and aqueous solutions (no harmful chemicals). This opens up the possibillity to scale up the production to bulk scale and possibly replace some of the petroleum based fibers commonly used today.
We expect that we will be able to produce artificial silk fibers with tensile strength that of native spider silk within the time frame of ARTSILK.
Photo of biomimetic artificial spider silk fibers (Schmuck et al. Materials Today. 2021)