WISS: Why Is Silk Spun? Integrating bio-rheology with advanced spectroscopic techniques

丝绸作为生物材料的个性在它成为纤维之前就已经确立了。与其他生物聚合物不同的是，蚕丝不像头发、骨头和羽毛那样需要数月或数年才能缓慢生长，而是通过纺纱在几秒钟内产生。虽然这种方法在自然界中是独特的，但它是人类熟悉的领域，因此使丝绸作为模型生物聚合物具有高度相关性;它是在熟悉的溶剂纺丝过程中制造的，这反过来又可以进行实验室研究。因此，我们现在有了背景和方法来问;考虑到自然界已经有了纳米级材料沉积的现有机制，为什么会进化出一种全新的生物制造工艺，它是如何工作的，我们可以从中学到什么？这项拟议的研究旨在调查为什么丝蛋白在生物材料中是独一无二的，因为它已经被优化用于流动加工（即纺纱）。拟议的工作将建立在以前的工作丝蛋白结构的解决方案，但将引入新的集成流变光谱工具来动态研究这些系统。具体来说，我们的研究目标是：（一）发展，完善和扩大我们的本体流变学测量的丝蛋白;（二）光谱确定丝蛋白结构的变化下流动;（iii）观察丝蛋白在流动下的变性和聚集动力学以及多尺度分级结构的发展，并且重要的是提供多学科培训的博士.phil学生在物理和生命科学的接口.这个项目提供了无与伦比的机会，了解一种新的生物加工技术的起源，有直接影响我们自己的工业生产对环境无害的聚合物，并将在各种不同的条件和应用中以优异的性能运行。这项研究的结果将挑战我们对蛋白质折叠和聚集的理解，解决从进化生物学到软凝聚态物理学的问题。

Silk's individuality as a biological material is established before it even becomes a fibre. Quite unlike any other biopolymer, silk is not grown slowly over months and years like hair bone and feathers, but produced in a matter of seconds through the act of spinning. Whilst this approach is unique in the natural world, it is familiar territory to man, thus making silk highly relevant as a model biopolymer; it is fabricated in a familiar solvent-spinning process, which in turn is accessible to laboratory investigation. Hence we now have the background and means to ask; given that Nature already had existing mechanisms for nano-scale deposition of materials, why was a fundamentally new biofabrication process evolved, how does it work and what can we learn from it? The proposed study sets out to investigate why silk proteins are unique amongst biological materials in having been optimised for flow processing (i.e. spinning). The proposed work will build on previous work on silk protein structures in solution but will introduce novel integrated rheo-spectroscopic tools to study these systems dynamically. Specifically our research aims to: (i) develop, refine and extend our bulk rheological measurements on silk proteins; (ii) spectroscopically determine silk protein structural changes under flow; (iii) observe silk protein denaturation and aggregation kinetics under flow and the development of multiscale hierarchical structures and - importantly - (iv) offer multidisciplinary training for a D.phil student at the interface of the physical and the life sciences.This project offers the unparalleled opportunity to understand the origins of a novel bioprocessing technology that has direct implications for our own industrial production of polymers that are environmentally benign and will operate in a wide range of different conditions and applications with exceptional properties. The outcome of this research will challenge our understanding of why proteins fold and aggregate, addressing questions from evolutionary biology to soft condensed matter physics.