Spider dragline silk is notable for it’s extraordinary mechanical properties. The material combines moderate strength and good extensibility, yielding a remarkable toughness exceeding that of all other natural or synthetic fibers. We show, that the strength of spider silk is based on the hierarchical structure of the fiber. The fiber shows a core-shell structure with the core comprising proteinaceous fibrils whereby the proteins contain a highly repetitive central domain flanked by two non-repetitive terminal domains. Although spider silk has been in the focus of research for several decades, the mechanical properties, especially the toughness of artificially made fibers have never reached those of natural spider silk before until recently.
Proceeding from Araneus diadematus fibroin 3 (ADF3), a spider silk protein (Spidroin), which was identified in the dragline silk of the European garden cross spider, two spidroin derivates for recombinant production in E. coli have been designed. Here two essential requirements for tough fibers are highlighted: First the contribution and composition of the spidroin domains to pre-assembly and second the processing method, which supports fiber formation. The toughness of our man-made fibers equals that of the natural fiber depending on the used spidroin derivate and the used processing method (biomimetic self-assembly)
Beside the biomimetic production of tough monofilaments and yarns, centrifuge electrospinning is introduced as a new highly efficient method to manufacture non-woven mats made of recombinant spider silk with high potential for biomedical applications.