Periodic Reporting for period 4 - ARTSILK (Novel approaches to the generation of artificial spider silk superfibers)
Okres sprawozdawczy: 2023-11-01 do 2024-10-31
The problem that ARTSILK targeted was the lack of sustainable high-performance biobased fibers. The development of such fibers is important since the society currently is dependent on petroleum based materials and the processing of fibers made from alternative sources is far from sustainable.
The overall objective of ARTSILK was to use state-of-the-art technologies to generate artificial silk fibers that are equal or superior mechancial properties compared to native spider silk. We aimed to achieve this by studying basic silk gland biology to get a deeper understanding about the composition and processing of spider silk fibers. Furthermore, ARTSILK also contained a strategy that would allow us to do something that nature cannot do - which is to incoprorate hydrophobic residues in the poly-Ala blocks of the recombinant spider silk proteins we produce. This would in theory lead to fibers with increased tensile trength and toughness. Finally, we also aimed to develop a novel spinning set-up for improved fiber properties.
The overall objective of ARTSILK was to use state-of-the-art technologies to generate artificial silk fibers that are equal or superior mechancial properties compared to native spider silk. We aimed to achieve this by studying basic silk gland biology to get a deeper understanding about the composition and processing of spider silk fibers. Furthermore, ARTSILK also contained a strategy that would allow us to do something that nature cannot do - which is to incoprorate hydrophobic residues in the poly-Ala blocks of the recombinant spider silk proteins we produce. This would in theory lead to fibers with increased tensile trength and toughness. Finally, we also aimed to develop a novel spinning set-up for improved fiber properties.
ARTSILK was succesful in completing all of the set goals:
The full characterization of the major ampullate gland by genomic, bulkRNA, single cell RNA and spatial transcriptomics sequencing was published recently (Sonavane et al. Science Advances. 2024). This work revealed that there are six cell types in the gland that are spatially distinct in their distribution and that produces specific mixtures of spider silk proteins. Furthermore, we could show that the protein mixtures form three layers in the final fiber.
The previously unexplored strategy to incoprorate hydrophobic amino acid residues in the poly-Ala blocks of the spider silk proteins was a success. We could, by using this strategy, produce artificial silk fibers with the same toughness as native spider silk while still keeping the all-aqueous processing conditions (Arndt et al. Advanced Functional Materials. 2022). A surprising finding was that most ofthese modified recombinant spider silk proteins could be produced as efficiently as the unmodified protein.
We have also 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, in particular since also the protein engineered proteins that gave superior fibers also could be produced at the same extreme levels. The work was published by Schmuck et al in Materials Today in 2021 and in et al. Advanced Functional Materials. 2022, and received a lot of media attention. We have also managed to improve the properties of our fibers by optimizing the rheological properties of our spinning dope (Arndt et al. ACS Biomaterials Science and Engineering 2021) and by screening almost 100 different spinning conditions and by making changes to the spinning device (Gonska et al. Biomacromolecules. 2020; Greco et al. Communications materials. 2021; Schmuck et al Communications materials. 2022; Greco ACS Applied Polymer Materials. 2024). As a result of our success we have received funding from industrial partners and two Proof of Concept grants to further develop our fibers and scale up the spinning method.
The work performed in ARTSILK has been disseminated through various channels: national TV and radio, several international magazines and daily newspapers, lectures for the public, a chapter in a popular scientific book, outreach activities at science festivals, visit to the lab by school classes and representatives from different authorities. Scientifically we have been very productive in reporting our findings and results in scientific journals and presented the work at several international conferences. Furthermore, we have submitted three patent applications based on finding s in ARTISLK, and have received funding to explore the possibility of commercializing our material.
The full characterization of the major ampullate gland by genomic, bulkRNA, single cell RNA and spatial transcriptomics sequencing was published recently (Sonavane et al. Science Advances. 2024). This work revealed that there are six cell types in the gland that are spatially distinct in their distribution and that produces specific mixtures of spider silk proteins. Furthermore, we could show that the protein mixtures form three layers in the final fiber.
The previously unexplored strategy to incoprorate hydrophobic amino acid residues in the poly-Ala blocks of the spider silk proteins was a success. We could, by using this strategy, produce artificial silk fibers with the same toughness as native spider silk while still keeping the all-aqueous processing conditions (Arndt et al. Advanced Functional Materials. 2022). A surprising finding was that most ofthese modified recombinant spider silk proteins could be produced as efficiently as the unmodified protein.
We have also 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, in particular since also the protein engineered proteins that gave superior fibers also could be produced at the same extreme levels. The work was published by Schmuck et al in Materials Today in 2021 and in et al. Advanced Functional Materials. 2022, and received a lot of media attention. We have also managed to improve the properties of our fibers by optimizing the rheological properties of our spinning dope (Arndt et al. ACS Biomaterials Science and Engineering 2021) and by screening almost 100 different spinning conditions and by making changes to the spinning device (Gonska et al. Biomacromolecules. 2020; Greco et al. Communications materials. 2021; Schmuck et al Communications materials. 2022; Greco ACS Applied Polymer Materials. 2024). As a result of our success we have received funding from industrial partners and two Proof of Concept grants to further develop our fibers and scale up the spinning method.
The work performed in ARTSILK has been disseminated through various channels: national TV and radio, several international magazines and daily newspapers, lectures for the public, a chapter in a popular scientific book, outreach activities at science festivals, visit to the lab by school classes and representatives from different authorities. Scientifically we have been very productive in reporting our findings and results in scientific journals and presented the work at several international conferences. Furthermore, we have submitted three patent applications based on finding s in ARTISLK, and have received funding to explore the possibility of commercializing our material.
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 (purely aqueous-based), and are tougher than nylon and kevlar. We are currently scaling up the spinning method with the aim to make yarns and textiles. We have also deepened the knowledge of how spider silk fibers are produced, and revealed their architecture and protein composition. An unexpected finding in ARTSILK was that the recombinant spider silk proteins are stable in solution at room temperature for days but quickly form robust transparent and self-sustaining hydrogels when incubated at 37 degrees C. Futhermore the silk proteins can be fused to other proteins of interest and still form hydrogels with intact function of the fusion partner (Arndt et al. Nature Communications. 2022). This is unique and means that we do not have to use cross-linkers, extreme temperatures or UV-light to form gels. Since the conditions for forming the gels are so mild, we speculated that we could also incoprorate cells in the gels, which was shown to work out beautifully (Anrdt et al. Advanced Functional Materials. 2024). This means that we have developed a novel method for immobilizing proteins in a three-dimensional hydrogel and for encapsulating living cells, simply by elevating the temperature to 37 degrees.