An integrated NMR/magnetic nanosensor system for detection of bacteria and toxins

用于检测细菌和毒素的集成核磁共振/磁性纳米传感器系统

• 批准号: 7915429
• 负责人: J Manuel Perez
• 金额: $ 33.64万
• 依托单位: UNIVERSITY OF CENTRAL FLORIDA
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7915429
• 关键词: Africa; Antibodies; Applications Grants; Bacillus anthracis; Bacteria; Bacterial Infections; Biological; Biological Assay; Biomedical Research; Blood; Blood specimen; Chemicals; Clinical; Crohn' s disease; Data; Detection; Diagnostic; Diagnostic tests; Drug resistance in tuberculosis; Enzyme-Linked Immunosorbent Assay; Escherichia coli EHEC; Escherichia coli O157; Food; Goals; Gold; Health Care Sector; Magnetism; Milk; Modeling; Molecular; Molecular Target; Monitor; Mycobacterium avium; Nature; Oligonucleotides; Paratuberculosis; Patients; Preparation; Principal Investigator; Proteins; Relaxation; Research; Ricin; Sampling; Signal Transduction; Specificity; Speed; System; Technology; Time; Toxin; United States; Viral Proteins; Water; Western Blotting; anthrax lethal factor; anthrax toxin; base; clinical decision-making; cost; detector; economic impact; edema factor; miniaturize; nanoparticle; nanoscale; nanosensors; nanoswitch; pathogen; point-of-care diagnostics; public health relevance; small molecule

DESCRIPTION (provided by applicant): Enabling diagnostic technologies that merge the use of nanoscale components and miniaturized detector systems could have a great impact in point-of -care diagnostics. In particular, diagnostic systems that are sensitive, robust, portable, low-cost, and can accurately quantify multiple molecular targets in parallel, would have a tremendous impact in biomedical research and molecular diagnostics. In this application, we propose to use a magnetic nanosensor technology, in conjunction with a portable magnetic relaxometer, to develop a sensitive diagnostic test for intracellular pathogens and toxins in clinical samples. Bacterial infections are on the rise in the United States and their economic impact on the healthcare sector is significant. The presence of enterohemorrhagic E. coli O157:H7 in tainted produce, the B. anthracis attacks in 2001, and the recent identification of drug resistant Mycobacterium tuberculosis have sparked public concern and underscore the need to develop sensitive and portable diagnostic technologies for fast and accurate detection of bacteria and toxins in food and clinical samples. Our approach utilizes "magnetic relaxation nanoswitches" (MRnS), i.e. magnetic nanoparticles that selectively change the spin-spin relaxation times (T2) of surrounding water molecules (NMR signal) upon specific molecular target interaction. The principal investigator of this grant application has previously shown that this technology can detect oligonucleotides in the femtomolemole range with extremely high molecular specificity [Nature Biotech. 2002;20:816-820], as well as other molecular targets such as proteins and viruses, without the need of target amplification. Most recently, we have developed magnetic nanosensors for the detection of a particular bacterium in blood and milk [Nanoletters 2007; 7, 380]. Also, with collaborators at the Army's Edgewood Chemical and Biological Center, we have gathered preliminary data to detect ricin toxin, using magnetic nanosensors. As a detector, we have used a newly developed minituarized and portable NMR relaxometer that allows substantial improvement in detection threshold and speed. The overall goal of this application is to extend research on magnetic nanosensors in an effort to develop highly sensitive, minituarized and portable detection systems to screen for the presence of a particular bacterium and toxin in clinical samples. We hypothesize that our magnetic nanoparticle system can provide a single homogeneous assay that can be used to detect the presence of intracellular pathogens and toxins in blood, without the need for target amplification. As an intracellular bacterial pathogen model, we will use Mycobacterium avium spp. paratuberculosis (MAP). As a toxin model, we will use anthrax toxin (AT), which is produced by another intracellular pathogen; B. anthracis. PUBLIC HEALTH RELEVANCE In this project, we will develop a diagnostic technology that merges the use of magnetic nanoparticles and a miniaturized detector to monitor the presence of an intracellular pathogen and toxin in clinical samples. This technology could facilitate quick, selective and sensitive bacterial detection to support clinical decision making.

描述（由申请人提供）：将纳米级组件和微型检测器系统的使用相结合的诊断技术可能会对现场诊断产生巨大影响。特别是，灵敏、稳健、便携、低成本且能够准确并行量化多个分子靶标的诊断系统将对生物医学研究和分子诊断产生巨大影响。在此应用中，我们建议使用磁性纳米传感器技术与便携式磁性松弛计相结合，开发针对临床样本中细胞内病原体和毒素的灵敏诊断测试。在美国，细菌感染呈上升趋势，其对医疗保健行业的经济影响巨大。受污染农产品中存在的肠出血性大肠杆菌 O157:H7、2001 年炭疽杆菌袭击以及最近发现的耐药结核分枝杆菌引起了公众的关注，并强调了开发灵敏、便携式诊断技术以实现快速、准确的必要性检测食品和临床样本中的细菌和毒素。我们的方法利用“磁弛豫纳米开关”（MRnS），即磁性纳米颗粒，可根据特定的分子目标相互作用选择性地改变周围水分子（NMR 信号）的自旋-自旋弛豫时间（T2）。该资助申请的主要研究人员此前已表明，该技术可以以极高的分子特异性检测飞摩尔范围内的寡核苷酸[Nature Biotech。 2002;20:816-820]，以及其他分子靶标，如蛋白质和病毒，无需靶标放大。最近，我们开发了磁性纳米传感器，用于检测血液和牛奶中的特定细菌[Nanoletters 2007； 7, 380]。此外，我们与陆军埃奇伍德化学和生物中心的合作者一起，收集了使用磁性纳米传感器检测蓖麻毒素的初步数据。作为检测器，我们使用了新开发的小型化便携式核磁共振弛豫计，可大幅提高检测阈值和速度。该应用的总体目标是扩展磁性纳米传感器的研究，努力开发高灵敏度、小型化和便携式检测系统，以筛选临床样本中特定细菌和毒素的存在。我们假设我们的磁性纳米颗粒系统可以提供单一均质测定，可用于检测血液中细胞内病原体和毒素的存在，而不需要目标放大。作为细胞内细菌病原体模型，我们将使用鸟分枝杆菌属。副结核病（MAP）。作为毒素模型，我们将使用炭疽毒素（AT），它是由另一种细胞内病原体产生的； B.炭疽病。公共健康相关性 在这个项目中，我们将开发一种诊断技术，将磁性纳米颗粒和小型探测器结合起来使用，以监测临床样本中细胞内病原体和毒素的存在。该技术可以促进快速、选择性和灵敏的细菌检测，以支持临床决策。