Biomimetic Fibers Made of Recombinant Spidroins with the Same Toughness as Natural Spider Silk

摘要

Spider dragline silk exhibits extraordinary mechanical properties combining a moderate strength with good extensibility resulting in a toughness exceeding that of all other natural or synthetic fibers. Although spider silk has been in the focus of research since decades, the mechanical properties, especially the toughness, of reconstituted man-made fibers have never reached those of natural spider silk. The properties are based on the underlying spider silk proteins (spidroins), their self-assembly and their explicit processing. Here, two out of three pre-requisites for tough fibers are tackled; the contribution of individual spidroin domains to assembly is analyzed, and processing of recombinant spidroins into fibers is shown. Fiber toughness upon processing equals and even slightly exceeds that of natural ones dependent on both the underlying proteins and preparation (biomimetic self-assembly) of the silk dope, although the overall strength is lower based on the used and simplified single-protein set-up.