Engineering, processing and application of recombinant spider silk proteins
Thomas Scheibel, University of Bayreuth, Germany
Hosts: Cecília Roque, UCIBIO, NOVA
ZOOM link: https://ucibio.pt/l/GuestSeminars
Abstract:
Proteins reflect one fascinating class of natural polymers with huge potential for technical as well as biomedical applications. One well-known example is spider silk, a protein fiber with excellent mechanical properties such as strength and toughness. We have developed biotechnological methods using bacteria as production hosts which produce structural proteins mimicking the natural ones [1]. Besides the recombinant protein fabrication, we analyzed the natural assembly processes and we have developed spinning techniques to produce protein threads closely resembling natural silk fibers [2]. To better understand the natural process, we recombinantly co-produced two different spider silk proteins in E. coli, yielding a mixture of homo- and heterodimers. Intermolecular interactions of these proteins in aqueous spinning dopes enabled their self-assembly into higher-order structures. Upon biomimetic spinning, nature-like performing fibers could be obtained concerning all important mechanical features such as tensile strength, elasticity, Young’s modulus as well as toughness.
Our findings emphasize the importance of protein interplay for functional complexity, ultimately providing a road map to design green high-performance fibers [3, 4].
In addition to fibers, we employ silk proteins in other application forms such as hydrogels, particles or films with tailored properties, which can be employed especially for biomaterials applications [5]. In biomedical applications the performance of materials largely depends on their surfaces and is further strictly related to the materials biocompatibility. Often the appearance of unwanted side effects hampers the applicability of biomaterials including foreign body responses and inflammation, and interaction of cells with a material’s surface, for example cell adhesion [6, 7]. In case of implants or catheters cell adhesion plays a crucial role for the overall function of the to-be-used material. To change the properties of in-use polymers and to adopt their biocompatibility, we established coatings based on engineered spider silk proteins. All kinds of polymers (polyurethane, polytetrafluoroethylene, silicone) have so far be stably coated with recombinant spider silk proteins, which can themselves be functionalized [8, 9]. Spider silk hydrogels can also be employed as new bioinks for biofabrication. Their elastic behavior dominates over the viscous behavior over the whole angular frequency range with a low viscosity flow behavior and good form stability. No structural changes occur during the printing process, and the hydrogels solidify immediately after printing by robotic dispensing. Due to the form stability it was possible to directly print multiple layers on top of each other without structural collapse. Cell-loaded spider silk constructs can be easily printed without the need of additional cross-linkers or thickeners for mechanical stabilization [10].
Our bio-inspired approach serves as a basis for new materials in a variety of medical, biological, or technical applications. Our technology has been further the basis for the biotech spin-off company AMSilk GmbH founded in 2008 focusing on scale-up and product development. First products containing spider silk-based proteins are already established.
References
[1]. Heidebrecht, A.; Scheibel T. Recombinant production of spider silk proteins. Adv. Appl. Microbiol. 2013, 82, 115-153
[2]. Heidebrecht, A.; Eisoldt, L.; Diehl, J.; Schmidt, A.; Geffers, M.; Lang, G.; Scheibel, T. Biomimetic Fibers Made of Recombinant Spidroins with the Same Toughness as Natural Spider Silk. Advanced Materials, 2015, 27, 2189–2194.
[3]. Saric, M., Eisoldt, L., Döring, V., Scheibel, T. (2021) Interplay of Different Major Ampullate Spidroins During Assembly and Implications for Fiber Mechanics. Advanced Materials, 2021, 33, 2006499
[4]. Saric, M.; Scheibel, T. Two-In-One Spider Silk Protein with Combined Mechanical Features in All-Aqueous Spun Fibers. Biomacromolecules, 2023, 24, 1744–1750
[5]. Aigner, T.B.; DeSimone, E.; Scheibel T. Biomedical applications of recombinant silk-based materials. Advanced Materials, 2018, 30, 1704636
[6]. Trossmann, V.; Scheibel, T. Design of Recombinant Spider Silk Proteins for Cell Type Specific Binding. Adv. Healthcare Mater, 2022, 12, 2202660
[7]. Lentz, S.; Trossmann, V.; Scheibel, T. Selective Topography Directed Cell Adhesion on Spider Silk Surfaces. Advanced Materials Interfaces, 2023, 10, 2201936
[8]. Borkner, C.; Elsner, M.; Scheibel, T. Coatings and Films Made of Silk Proteins. Appl. Mater. Interface, 2014, 6, 15611-15625
[9]. Kumari, S.; Lang, G.; DeSimone, E.Ö Spengler, C.; Trossmann, V.; Lücker, S.; Hudel, M.; Jacobs, K.; Krämer, N.; Scheibel, T. Engineered spider silk-based 2D and 3D materials prevent microbial infestation. Materials Today, 2020, 41, 21-33
[10]. Neubauer, V., Trossmann, V., Jacobi, S., Döbl, A., Scheibel, T. Aqueous-Organic Solvent Derived Recombinant Spider Silk Gels as Depots for Drugs. Angew. Chem. Int. Ed., 2021, 60, 11847-11851
Short Bio:
Prof. Dr. Thomas Scheibel is full professor for Biomaterials as well as Vice President for internationalization, gender equality and diversity at the University of Bayreuth. Since 2014 he is a member of the German National Academy of Science and Engineering (acatech). He initiated and chairs the topical committee on “Bioinspired and interactive materials” at the Germen Materials Society (DGM), is chairman of the Bayreuth-Melbourne Colloid & Polymer network, co-chairman of the TranregioSFB TRR225 “Biofabrication”, Member of the review board “biomaterials” of the DFG, Advisory Board Member of German Association for Resource Efficiency and Additive Manufacturing (GRAT), co-founder and shareholder of AMSilk GmbH, groupleader of the Neue Materialien Bayreuth GmbH (NMB), and Director of BayHost (Bavarian Academic Center for Central, Eastern and Southeastern Europe).