Production of Synthetic Spider Silk

Ryan Matthew Hekman, University of the Pacific

Abstract

Spider silk is a material that both has impressive mechanical properties and is also environmentally friendly. Though there are limitless potential engineering applications for such materials, industrial production of spider silk has proven to be challenging. Farming silk from spiders, as is done with silkworms, is not a viable option for large-scale production of spider silk due to the venomous and predatory nature of spiders. Here, an attempt is made to express synthetic spider silk minifibroins heterologously in Escherichia coli, to purify the recombinant spidroins from cell lysate, and to spin them into artificial fibers through a biomimetic process. Silk minifibroins were designed to be similar to Major Ampullate Spidroin 1 from Latrodectus hesperus. Synthetic fibers were examined by scanning electron and light microscopy, and their mechanical properties were tested by a tensometer. Properties of synthetic silk were compared to those of native dragline silk from the same species from which their design was inspired, revealing synthetic silk fibers with lower breaking stress and breaking strain.