A biobased economy is a prerequisite for the transition into a sustainable society. An important part of this transition is the development of novel, biobased materials that can be produced in a sustainable way using renewable resources. However, we are still heavily dependent on materials made from fossil raw materials, especially when it comes to high-performance fibers. A potentially very interesting material in this context is spider silk, Nature’s toughest fiber. Spider silk is attractive for use as e.g. textiles, reinforcement in composite construction materials and as implants for applications in regenerative medicine. However, production and spinning of artificial spider silk fibers have shown to be very challenging, and current methods to produce silk fibers use harsh solvents and denaturing conditions. These methods not only are harmful to the environment but also prevent the silk proteins from assembling into fibers in the same complex way that native silk proteins do.
We have recently made marked progress in establishing a sustainable and scalable process for making artificial spider silk: 1) we have developed a process for spinning biomimetic artificial spider silk fibers (using water as the sole solvent); 2) by using a protein engineering approach, we have markedly increased the mechanical properties of the fibers, which now approach those of the native fiber; and 3) we have developed a process that results in unprecedented levels of recombinant silk proteins by using a bioreactor. From the protein extracted from a 1-liter bacterial culture, we can extract enough protein to spin an 80km long fiber. Hence, we can now, for the first time, produce continuous artificial spider silk fibers in a process that is devoid of organic solvents and at a scale and cost that is compatible with industrial applications. The overall objective of ArtSilkTex was therefore to show that we can spin multifilament fibers that can be used to make yarns, protect IP, and establish a route to commercialization.
