Nanostructured Protein Surfaces Inspired by Spider Silk

Spider silk is renowned for its exceptional mechanical properties, surpassing those of many natural and synthetic materials. This review focuses on biotechnologically produced recombinant spidroin variants inspired by well-understood major ampullate spider silk proteins (=spidroins), which are role models for understanding molecular composition, architecture, and the nanoscopic and mesoscopic structures formed through self-assembly and phase separation of spider silk fibers. The use of recombinant spidroins is explored to fabricate functionalized nanostructured surfaces, and molecular engineering is highlighted to tailor the interfacial properties of various morphologies, including particles, capsules, electrospun nanofibers, films/coatings, macroscopic nanofibril-based hydrogels, and nanohydrogel coatings. One focus is on functionalization of spidroins with peptide tags enabling a variety of affinity-based targets from cellular markers to inorganic nanoparticles, and allowing for instance specific drug delivery, cell accommodation in hydrogels, or bioselective immobilization of cells on surfaces. Furthermore, applying nanostructured spidroin coatings in combination with photo- and soft-lithography techniques is demonstrated, which can be used to produce micro- and nanostructured patterns exhibiting confined, spidroin-defined targeting, affinity, or repulsion properties.