Collaborative Research: Controlled Investigation of Micro- and Nanoscale Contact Interactions Between Microbes and Biomaterials Using Artificial Bacteria

合作研究：使用人造细菌对微生物与生物材料之间的微米和纳米尺度接触相互作用进行受控研究

基本信息

批准号：
1761060
负责人：
MinJun Kim
金额：
$ 26.89万
依托单位：
Southern Methodist University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-07-01 至 2022-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1761060&HistoricalAwards=false
关键词：
Collaborative Research Controlled Investigation Micro

项目摘要

Moving bacteria and cells transport themselves though very dense environments of long molecules during normal biological processes and disease. Examples are sperm that travel through mucus in reproduction, bacteria of the nose, lung or gut penetrating mucus during infection, and soil and oceanic bacteria migrating through a bacterial mat of long-chain molecules. The molecules of mucus and other molecules of the body are often about the same length as a microbe. This means that individual and unpredictable interactions between microbes and molecules change how the microbes move. Experimental evidence suggests that microbial transport though such materials could be dominated by direct contact interactions with the individual molecules. Contact interactions are difficult to measure and their effect on locomotion is difficult to quantify. The overall goal of this research is to quantify the effect of direct contact interactions on the propulsion of bacteria. The research will use novel artificial bacteria, 'microrobots', and manufactured mucus to discover which contact interactions dominate transport. The data will improve our ability to understand, perhaps to control, the movement and spread of microorganisms in real-world environments. The investigators will work with local K-12 students in an outreach program named "Move Like a Microbe." The goal of the outreach is to intrigue the students using new understanding of bacterial mobility and encourage them into a science or technology (STEM) path in their later education. Understanding the nanomechanics of microbe transport also will improve our abilities to control disease and understand normal bacterial behavior.Microstructural interactions with swimming microorganisms have mostly been investigated using hydrodynamic and mechanical models. There has been no in-depth examination of the role of contact interactions mediated by electrostatic forces, van der Waals attraction, and biochemical bonding. This research will advance understanding of bacterial transport by combining new microrobotic artificial bacteria systems and a novel semisynthetic mucus to allow well-controlled and well-characterized experiments. The artificial models allow control of density, stiffness, surface charge, surface chemistry, and micromechanical properties, to clarify the relative importance of hydrodynamic, close-range, and nanoscale contact interactions for microbial transport through biological media. Numerical modeling will be used to integrate the interactions into quantitative models of transport. Finally, natural bacteria will be observed moving through well-defined biomaterials and their behavior will be correlated with that observed in the artificial systems, in order to identify which contact interactions are most important for biologically relevant scenarios, testing the hypothesis that contact interactions dominate the effect of organism-scale microstructure on bacterial swimming.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在正常的生物过程和疾病期间，移动的细菌和细胞通过非常密集的长分子环境运输自身。例如，在繁殖过程中穿过粘液的精子，在感染过程中穿过粘液的鼻子、肺或肠道细菌，以及通过长链分子的细菌垫迁移的土壤和海洋细菌。粘液分子和身体的其他分子通常与微生物的长度大致相同。这意味着微生物和分子之间个体和不可预测的相互作用会改变微生物的移动方式。实验证据表明，微生物通过此类材料的运输可能由与单个分子的直接接触相互作用主导。接触相互作用很难测量，并且它们对运动的影响也很难量化。这项研究的总体目标是量化直接接触相互作用对细菌推进的影响。该研究将使用新型人造细菌、“微型机器人”和人造粘液来发现哪种接触相互作用主导运输。这些数据将提高我们理解、或许控制微生物在现实环境中的运动和传播的能力。调查人员将与当地 K-12 学生合作开展一项名为“像微生物一样移动”的外展项目。外展活动的目标是激发学生对细菌流动性的新认识，并鼓励他们在以后的教育中走上科学或技术 (STEM) 道路。了解微生物运输的纳米力学也将提高我们控制疾病和理解正常细菌行为的能力。游动微生物的微观结构相互作用主要是使用流体动力学和力学模型来研究的。目前还没有对静电力、范德华引力和生化键介导的接触相互作用的作用进行深入研究。这项研究将通过结合新型微型机器人人工细菌系统和新型半合成粘液来促进对细菌运输的理解，以实现良好控制和良好表征的实验。人工模型可以控制密度、刚度、表面电荷、表面化学和微机械特性，以阐明流体动力学、近距离和纳米级接触相互作用对于微生物通过生物介质运输的相对重要性。数值模型将用于将相互作用整合到运输的定量模型中。最后，将观察天然细菌在明确定义的生物材料中移动，并且它们的行为将与在人工系统中观察到的行为相关联，以便确定哪些接触相互作用对于生物相关场景最重要，测试接触相互作用主导细菌的假设。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。