Structure, dynamics and mechanical properties in soft matter and biological systems

我研究软凝聚态系统，以了解它们如何保持形状，在自身重量下支撑自己，并抵抗变形，尽管它们非常柔软。我使用的是悬浮在液体中的微米大小的胶体球模型，我们在其中加入了一种吸引力，我们可以控制它的范围和强度。这些球体可以形成晶体或冻结成非平衡固体-玻璃或凝胶-与拥挤或增加的吸引力。由于球体被荧光标记，并且移动得足够慢，可以在真实的时间内观察它们，因此我们可以使用共聚焦显微镜在真实的空间中直接研究这些非平衡固体的结构和动力学。这些都是凝聚态物理学中最吸引人的问题，我的工作自然会转移到生物学上，因为细胞不断地执行任务，永远被赶出平衡。我们应用我们从软凝聚态物理学中获得的知识--物质是如何聚集的？软材料具有什么样的机械性能、动力学或结构？- 来探索细胞结构的问题。虽然生物学家已经定性地阐明了当细胞骨架--赋予细胞形状的结构--组装和拆卸时会发生什么，但对所涉及的力量知之甚少。在与解剖学和细胞生物学教授克雷格蒙达托的合作中，我正在探索细胞结构的力学，重点是构成细胞骨架的纤维的作用。由于癌症化疗靶向恶性细胞中的这些纤维，这项研究可能具有重要的治疗意义。

I study soft condensed matter systems to learn how they keep their shape, support themselves under their own weight and resist deformation despite the fact that they are extremely soft. I do this using model micrometer-sized colloidal spheres suspended in a fluid into which we add an attraction whose range and strength we control. These spheres can make crystals or freeze into nonequilibrium solids - glasses or gels - with crowding or with the added attraction. Because the spheres are fluorescently labeled and move slowly enough to allow watching them in real time, we can study directly in real space using a confocal microscopy the structure and dynamics of these nonequilibrium solids. These are some of the most fascinating questions in condensed matter physics.My work transfers naturally to biology, as cells are constantly performing tasks and forever driven out of equilibrium. We apply our knowledge from soft condensed matter physics - how do things assemble? What sorts of mechanical properties, dynamics, or structures do soft materials have? - to biology to explore these questions about cellular structures. While biologists have clarified qualitatively what happens when a cytoskeleton - the structure that gives cells their shapes - assembles and disassembles, little is known of the forces involved. In collaborations with Anatomy and Cell Biology professor Craig Mondato, I am exploring the mechanics of cellular structures, focusing on the role of the fibres that make up the cytoskeleton. And as cancer chemotherapies target these fibres in malignant cells, this research could have important therapeutic consequences.