Collaborative Research: Chiral objects in microfluidic shear flows: chiral separation and microbial locomotion

合作研究：微流体剪切流中的手性物体：手性分离和微生物运动

• 批准号: 0966000
• 负责人: Roman Stocker
• 金额: $ 20.71万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0966000&HistoricalAwards=false
• 关键词: Collaborative; Research; Chiral; objects; microfluidic

This project investigates the dynamics of chiral particles and chiral organisms in shear flows, using a combination of microfluidic experiments and mathematical modeling. Chiral particles are particles with shapes that cannot be superimposed upon their mirror images, and are of broad interest for both basic science and technology. Chiral particles are ubiquitous in biology: for example, amino acids are chiral molecules. Since the intermolecular reactions involved in life processes depend on the geometry of participating molecules, different enantiomers of chiral drugs, pheromones, pesticides, and odorants have different biological effects. As a consequence, there is much interest in devising ways to separate pure enantiomeric samples out of a mixture of both enantiomers. Furthermore, in biology chirality occurs not only at the molecular scale, but also at the cellular scale. Many swimming microorganisms have chiral helical structures, such as the propulsion-generating flagella of most bacteria. At the same time, the watery environments of microbes are constantly subject to fluid flow, and hence shear, such as in the oceans, groundwater, industrial pipe flow, and catheters. This project has two specific aims: (i) exploiting the chirality-dependent motion of particles in shear flows to separate a mixture of enantiomers by handedness in a microfluidic channel, and (ii) understanding how chiral morphologies of microbes affect their swimming and foraging. These aims are unified by the ultimate goal of better understanding the behavior of chiral particles in shear flows, and hence amenable to the same experimental and theoretical research tools. The proposed research has the potential to (i) transform our technological capability to separate a racemic mixture into component enantiomers, by developing a simpler and less expensive separation strategy than those currently available, and (ii) improve our understanding of microbial motility, with applications ranging from the recycling of limiting elements in natural systems to the spreading of disease and biofilm formation.

该项目结合微流体实验和数学建模，研究剪切流中手性粒子和手性生物体的动力学。手性粒子是形状不能叠加在其镜像上的粒子，对基础科学和技术具有广泛的兴趣。手性粒子在生物学中无处不在：例如，氨基酸就是手性分子。由于生命过程中涉及的分子间反应取决于参与分子的几何形状，因此手性药物、信息素、杀虫剂和气味剂的不同对映体具有不同的生物效应。因此，人们对设计从两种对映体混合物中分离纯对映体样品的方法非常感兴趣。此外，在生物学中，手性不仅发生在分子尺度上，而且还发生在细胞尺度上。许多游动微生物具有手性螺旋结构，例如大多数细菌产生推进力的“agella”。与此同时，微生物的水环境不断受到“流体”的影响，因此受到剪切力的影响，例如在海洋、地下水、工业管道流和导管中。该项目有两个具体目标：(i) 利用剪切流中粒子的手性依赖性运动，通过微流体通道中的手性分离对映体混合物，以及 (ii) 了解微生物的手性形态如何影响其游泳和觅食。这些目标与更好地理解剪切流中手性粒子行为的最终目标是一致的，因此适用于相同的实验和理论研究工具。拟议的研究有潜力（i）通过开发比现有技术更简单、更便宜的分离策略，转变我们将外消旋混合物分离成对映异构体的技术能力；（ii）提高我们对微生物运动的理解，其应用范围从自然系统中限制元素的回收到疾病的传播和生物膜的形成。