Silk and Silk-Like Supramolecular Materials.

Silk is a source of marvel for centuries as one of nature's high-performance materials. More recently, chemical and structural analysis techniques have helped explore the relationship between silk's properties and its hierarchical structure. Furthermore, recombinant protein engineering as well as polymer and organic synthesis techniques have enabled the production of silk-like materials. It has become apparent that silk is a supramolecular polymer with many of the properties exhibited by well-known synthetic supramolecular materials, such as block copolymers, liquid crystals, thermoplastic elastomers, and self-assembling peptides. In this review, the hierarchical structure and supramolecular assembly of silk are discussed in comparison to these synthetic supramolecular systems. By focusing on the connections between chemical structure, nanoscale molecular organization, and material properties, the aim is to provide perspectives on the rational design of advanced soft matter to supramolecular chemists and molecular engineers who look to nature for inspiration.