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

• 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

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，移动细菌和细胞会通过长分子的非常致密的环境来运输自身。 例子是精子，这些精子在繁殖过程中穿过粘液，鼻子的细菌，肺或肠道感染过程中穿透性粘液，土壤和海洋细菌通过长链分子的细菌MAT迁移。人体的粘液和其他分子的分子通常与微生物大约相同的长度。这意味着微生物与分子之间的个体和不可预测的相互作用改变了微生物的移动方式。 实验证据表明，虽然这种材料可以通过与单个分子直接接触相互作用来控制微生物的转运。 接触相互作用很难衡量，它们对运动的影响很难量化。 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。 该研究将使用新型的人造细菌，“微型机器人”和制造粘液，以发现哪种接触相互作用主导了运输。 数据将提高我们在现实环境中了解微生物的运动和传播的能力。调查人员将与当地的K-12学生一起参加一个名为“ Move Microbe”的外展计划。 宣传的目的是吸引学生对细菌流动性的新理解，并鼓励他们在以后的教育中进入科学或技术（STEM）。了解微生物运输的纳米力学还将提高我们控制疾病并理解正常细菌行为的能力。与游泳微生物的微结构相互作用主要是使用流体动力和机械模型研究的。 尚无对静电力，范德华吸引力和生化键合介导的接触相互作用的作用的深入研究。这项研究将通过结合新的微生物人造细菌系统和一种新型的半合成粘液来提高对细菌转运的理解，从而可以进行良好的控制和良好的特征化实验。人工模型允许控制密度，刚度，表面电荷，表面化学和微力特性，以阐明通过生物学介质对微生物传输的流体动力，近距离和纳米级接触相互作用的相对重要性。数值建模将用于将相互作用整合到传输的定量模型中。最后，将观察到天然细菌通过明确定义的生物材料进行，其行为将与人造系统中观察到的生物材料相关，以确定哪些接触相互作用对于生物学上相关的情景最重要，检验了接触相互作用的假设，即通过对细菌的奖励的效果来占主导地位，以证明有机化的效果。基金会的智力优点和更广泛的影响审查标准。

项目成果

Heterogeneously flagellated microswimmer behavior in viscous fluids

• DOI: 10.1063/1.5137743
• 发表时间: 2020-03-01
• 期刊: BIOMICROFLUIDICS
• 影响因子: 3.2
• 作者: Rogowski, Louis William;Oxner, Micah;Kim, Min Jun
• 通讯作者: Kim, Min Jun