To spin or not to spin: spider silk fibers and more.

Spider silk fibers have a sophisticated hierarchical structure composed of proteins with highly repetitive sequences. Their extraordinary mechanical properties, defined by a unique combination of strength and extensibility, are superior to most man-made fibers. Therefore, spider silk has fascinated mankind for thousands of years. However, due to their aggressive territorial behavior, farming of spiders is not feasible on a large scale. For this reason, biotechnological approaches were recently developed for the production of recombinant spider silk proteins. These recombinant proteins can be assembled into a variety of morphologies with a great range of properties for technical and medical applications. Here, the different approaches of biotechnological production and the advances in material processing toward various applications will be reviewed.