CAREER: Role of Surface Properties in Motility of Bacteria to Control Biofilms

ID：MPS/DMR/BMAT(7623)1151133 PI：Conrad，Jacinta ORG：University of Houston标题：Career：表面特性在细菌运动中的作用以控制生物膜INTELLECTUCTUAL优点：该项目的目标是以高空间和时间分辨率量化表面特性如何影响细菌的运动。运动性是表面结合细菌生物膜形成的关键因素。一旦生物膜形成，它们就很难去除，导致石油和供水管道、生物医学植入物和食品遭受数十亿美元的损失。降低这些成本需要新的策略来防止细菌形成生物膜。在生物膜形成的初始阶段，细菌修改其运动机制，使其能够不可逆地附着在附近的表面。为了验证细菌与表面之间的相互作用对细菌附着和脱落的运动特性和速率的影响这一假说，具体目的是：(1)通过测量表面运动的速度和持续性来阐明表面化学和弹性对扩散的影响。单细菌跟踪算法将被用来跟踪数千种细菌在表面上的运动，这些表面电荷和弹性系数是使用逐层沉积设计的，从而产生优化的表面特性，以最大限度地减少扩散。(2)对表面模式的方向性持续性进行量化。将使用趋化性模型分析细菌在特征尺寸为1-100微米的梯度表面上的均方位移、平均速度、持续时间和运动角度，从而产生关于表面图案如何指导细菌运动的基础数据。(3)开发通过测量单个细菌的附着率和分离率来评估防污表面的方法。这些速率将与在两种具有防污效果的表面上生成的生物膜的结构相关，这两种表面是两亲性聚合物膜和层次化皱纹表面。通过对表面性质对运动性、粘附性和生物膜形成的影响的新的基本了解，该项目旨在使涂层能够合理设计，以抑制细菌的定植，从而阻止生物膜的形成。BROADER影响：优化的防污涂层将有助于减少每年在供水和资源管道上造成的数十亿美元的生物腐蚀损害，以及与医院感染相关的成本。更广泛地说，对近表面运动性的详细显微研究将对细菌与其运动表面之间的相互作用产生新的见解，从而能够对感染和病理学以及防污表面特性进行定性的新研究。这项工作产生的信息丰富的数据将改进现有的定向运动和细菌黏附模型。最后，这些技术可以应用于将细菌附着和污垢与广泛的物种和表面的表面特性相关联。拟议的研究将与旨在增加休斯敦未得到充分服务的人口对工程的参与的教育和外联工作结合起来。首先，将与两所为少数族裔服务的当地高中(KIPP-Houston和DeBakey)合作开展关于生物污垢的培训和学习活动，以激励学生学习工程学，利用PI与NSF-RET和密歇根大学为大学预科女性介绍工程学的年级营计划正在进行的工作。其次，PI将继续通过UH和NSF-REU指导本科生的研究。最后，两名研究生将接受防污表面研究方面的指导，并将由PI发起生物工程的跨学科研讨会。拟议的教学和推广工作将扩大休斯敦不同人群对工程学的参与，这反映在KIPP-Houston和DeBakey分别有高比例的非裔美国人和拉丁裔学生(95%和56%)和低收入学生(80%和49%)。同样，PI将在休斯顿大学(13%是非洲裔美国人，21%是拉丁裔)继续开展这些活动，休斯顿大学是美国第二大多元化研究型大学。这项研究的结果将由PI和她的学生在科学文献以及石油和生物医学行业广泛传播，利用PI作为工业赞助的博士后研究员的经验和她在德克萨斯医学中心的持续合作。

ID: MPS/DMR/BMAT(7623) 1151133 PI: Conrad, Jacinta ORG: University of HoustonTitle: CAREER: Role of Surface Properties in Motility of Bacteria to Control BiofilmsINTELLECTUAL MERIT: The objective of this project is to quantify how surface properties influence the motility of bacteria, with high spatial and temporal resolution. Motility is a critical factor in the formation of surface-associated bacterial biofilms. Once biofilms form, they are notoriously difficult to remove, resulting in billions of dollars of damage to oil and water pipelines, biomedical implants, and food. Reducing these costs requires new strategies to prevent bacteria from forming biofilms. In the initial stage of biofilm formation, bacteria modify their motility mechanisms to enable irreversible attachment to nearby surfaces. To test the hypothesis that motility characteristics and rates of bacterial attachment and detachment are affected by the interactions between bacteria and surfaces, the specific aims are: (1) To elucidate the effects of surface chemistry and elasticity on dispersal by measuring velocity and persistence of motion on surfaces. Single-bacterium tracking algorithms will be used to track thousands of bacteria moving on surfaces with controlled surface charge and elastic modulus engineered using layer-by-layer deposition, yielding optimized surface properties to minimize dispersal. (2) To quantify directional persistence in response to surface patterns. The mean-square displacement, mean speed, persistence time, and angle of motion of bacteria on gradient surfaces with feature sizes of 1-100 microns will be analyzed using models for chemotaxis, yielding fundamental data on how surface patterns direct motion in bacteria. (3) To develop assays to evaluate antifouling surfaces by measuring attachment and detachment rates of individual bacteria. These rates will be correlated to the structure of the resultant biofilms on two types of surfaces with demonstrated antifouling efficacy, amphiphilic polymer films and hierarchically wrinkled surfaces. By generating new fundamental understanding of the effects of surface properties on motility, adhesion, and biofilm formation, this project aims to enable the rational design of coatings that inhibit colonization by bacteria and thereby impede biofilm formation.BROADER IMPACTS: Optimized antifouling coatings will help to reduce the billions of dollars in biocorrosion damage in water and resource pipelines each year and in costs related to hospital-acquired infections. More broadly, detailed microscopic investigations of near-surface motility will yield new insights on the interactions between bacteria and the surfaces on which they move, enabling qualitatively new studies of infection and pathology as well as antifouling surface properties. The information-rich data generated by this work will improve existing models for directed motility and for bacterial adhesion. Finally, these techniques can be applied to correlate bacterial attachment and fouling to surface properties across a wide range of species and surfaces. The proposed research will be integrated with educational and outreach efforts aimed at increasing the participation of underserved populations in engineering in Houston. First, training and learning activities on biofouling that inspire students to study engineering will be developed in collaboration with two minority-serving local high schools (KIPP-Houston and DeBakey), leveraging the PI's ongoing work with NSF-RET and the UH GRADE Camp program for introducing precollege women to engineering. Second, the PI will continue to mentor undergraduate students in research through UH and NSF-REU. Finally, two graduate students will be mentored in research on antifouling surfaces, and interdisciplinary workshops on engineering for biology will be initiated by the PI. The proposed teaching and outreach efforts will broaden participation in engineering throughout the diverse population of Houston, reflected by the high proportions of African American and Latino (95% and 56%) and low income (80% and 49%) students at KIPP-Houston and DeBakey, respectively. Likewise, the PI will pursue these activities at the University of Houston (13% African American and 21% Latino), the second most diverse research university in the US. The results from this study will be widely disseminated by the PI and her students in both the scientific literature and to the petroleum and biomedical industries, leveraging the PI's experience as an industrially sponsored postdoctoral researcher and her ongoing collaborations at the Texas Medical Center.