There are many techniques to spin spider silk, the easiest of which is wet spinning, in which the spidroins are dissolved in a chemical solution (for example, saturated ammonium, hexafluoroisopropanol in methanol, hexafluoroacetone hydrate in methanol, and formic acid in methanol) before entering a coagulation bath that removes the solvent and causes conformational changes [1, 2]. To do wet spinning, we need a microsyringe pump capable of extruding the dope at a flowrate as slow as 1 μL/min into a coagulation bath. Once the spidroins have coagulated, a post-spinning roller will collect the spider silk. Because of the microsyringe pump’s design, shear force will help in the coagulation process of the spidroins [1, 2, 3]. Moreover, once the spidroins and gold nanoparticles are in the syringe the oxygen will be purged with Nitrogen gas to increase the chances of binding the gold nanoparticles and spidroins together.
Figure. A) Microsyringe Pump based on a micro-controller-enabled stepper motor that pushes the syringe at the desired flowrate; B) Coagulation bath where the spidroins will be pushed into. This will be filled with a chemical such as isopropanol; and C) Post-spinning roller that will collect spider silk after it has coagulated.
References
- Rising, A., Johansson, J. Toward spinning artificial spider silk. Nat Chem Biol 11, 309–315 (2015). https://doi.org/10.1038/nchembio.1789.
- Madurga, R., Gañán-Calvo, A. M., Plaza, G. R., Guinea, G. V., Elices, M., & Pérez-Rigueiro, J. (2017). Production of High-Performance Bioinspired Silk Fibers by Straining Flow Spinning. Biomacromolecules, 18(4), 1127-1133. https://doi.org/10.1021/acs.biomac.6b01757.
- Andersson, M., Jia, Q., Abella, A., Lee, X.-Y., Landreh, M., Purhonen, P., Hebert, H., Tenje, M., Robinson, C. V., Meng, Q., Plaza, G. R., Johansson, J., & Rising, A. (2017). Biomimetic spinning of artificial spider silk from a chimeric minispidroin. Nature Chemical Biology, 13(3), 262-264. https://doi.org/10.1038/nchembio.2269.