Spider Silk Nanostructuring and its Applications for Tissue Engineering

This thesis introduces new ways to produce micro-and nanostructures of recombinant spider silk and explores ways to characterize their topography, mechanical properties, cell compatibility, and permeability. The suitability of the formed structures for applications within tissue engineering, primarily in vitro tissue modeling, is also investigated. One big challenge in drug development is that many drug candidates fail to pass in vivo studies in humans. This is largely because the currently used animal models fail to emulate the full human condition. Therefore, researchers aim to develop in vitro models of various tissues using human cells. These new systems will allow studies of biological responses and mechanisms related to human health and disease. To accurately represent what happens in the body, the materials used for cell culture should as closely as possible mimic their in vivo counterparts. Many of the materials used today are made out of plastic and lack physiologically relevant properties, and do not replicate the micro-and nano dimensions present in the native cell environment. Spider silk has been suggested as a suitable replacement material for cell culture. The usage of spider silk for medical purposes is not new; it was used already in ancient Greece and Rome to staunch wounds. However, the spider's limited production has haltered the applicability. Lately, new doors have opened up through recombinant production of the base constituent of silk: the spider silk protein (spidroin). Recombinant spidroin production is not only scalable but also allows for facile integration of additional biofunctionality. With this building material at hand, it is possible to produce other formats than spider silk fibers, i.e., coatings, films, membranes, hydrogels, porous scaffolds, and microparticles. With the work presented in this thesis, the list is extended through the introduction of new methods to produce nanomembranes and uniformly shaped micro-and nanostructures by manipulating the liquid:air interface. ...