An image-based analysis of recombinant silk fiber structures

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Project Description

Silk fibers represent an intriguing type of material from a material science perspective. Silk fibers derived from the cocoon of silk moths (Bombyx Moori) and the wide range of silks produced by spiders exhibit an array of features such as extraordinary tensile strength, elasticity and adhesive properties. Such functional features can be derived from the structural composition and organization of the silk fibers, however, there is currently a lack in understanding on the specifics of how the structural composition and organization relates to the ultimate function of silk fibers. Aside from knowing the fundamental protein composition, electron microscopy can reveal the surface fiber morphology and IR-spectroscopy the overall secondary structure content. However, the supramolecular organization in the fiber is very likely an important contributor to the ultimate function as well. This feature is what this project aims to study more in detail. Mechanical properties such as tensile strength rely on calculations that e.g. assume a given value of diameter. Getting an accurate estimation not only of a representative diameter but also of if and how it changes over the length of a fiber is important for mechanical testing data to be correctly interpreted. In addition, as most fibers are to a varying degree optically active and showcase birefringence, large scale internal silk fiber organization - thought to be strongly linked to the mechanical features of the fiber, can be investigated in a non-destructive way by studying the optical properties of the fibers.
The overall goal is to set up and implement an image-based analysis workflow to identify significant features of recombinant silk fibers as revealed by light microscopy. Combining this data with data from further measurements such as mechanical tensile testing and structural analysis by IR could provide a tangible link between the visual appearance of fibers and their structural and functional properties. This would then possibly enable a relatively fast and non-destructive quality control process for artificial spider silk manufacturing as well as provide further insight into the link between supramolecular organization and function of silk fibers.