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Investigation of zeolite systems: Focus on Fenton chemistry oxidative stress from asbestos like minerals and zeolite-based dissolved oxygen sensing.

机译：沸石系统的研究：集中于Fenton化学氧化应力，该应力来自石棉，如矿物和基于沸石的溶解氧传感。

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摘要

The research in this dissertation has focused on studying zeolite systems in two areas. The first goal of the research was to examine particle properties leading to hydroxyl radical related toxicity. The second goal was to create an efficient optical oxygen sensor for intracellular monitoring of oxygen. Asbestos is known to cause a variety of respiratory health problems; however, the exact mechanism leading to these problems is unknown. Typically, asbestos participates in Fenton chemistry producing hydroxyl radicals which lead to toxicity in vivo. During these times of oxidative stress in vivo, the intracellular oxygen is under flux. Being able to monitor the intracellular oxygen concentration can provide critical information related to the condition of the cell.;Initially, studies were performed focusing on Fenton chemistry and oxidative stress from asbestos like minerals. Researchers are striving to elucidate an exact mechanism of asbestos toxicity because it has led and is still leading to multiple respiratory health problems. The physicochemical characteristics of asbestos contributing to respiratory health problems are not fully defined. The goal of this research was to correlate particle toxicity with physicochemical characteristics to help eventually elucidate the mechanism of asbestos toxicity. After the asbestos is inhaled, the particles interact with lung lining fluid, which contains antioxidants. The antioxidants have the ability to reduce ferric iron on the asbestos particles. The particles are then phagocytosed by macrophages, and subsequently an oxidative burst is induced in an effort to remove the inhaled particles. During this oxidative burst, hydrogen peroxide is produced inducing Fenton chemistry with the ferrous iron. Mimicking the oxidative burst process with minerals having properties similar to that of asbestos, but different toxicities, can provide great insight as to the critical physicochemical characteristics related to toxicity. Mordenite, a benign aluminosilicate, and erionite, a highly carcinogenic aluminosilicate, were iron ion-exchanged, exposed to antioxidants, and then exposed to hydrogen peroxide to induce oxidative burst. Monitoring the production of hydroxyl radicals determined if differences between the physicochemical properties of the mineral aluminosilicates resulted in differing Fenton activity. The conclusion of this study was that the coordination of the iron on the mineral surface plays an important role in Fenton activity.;During the oxidative burst, a flux of oxygen within the cell occurs. Being able to monitor the hydroxyl radical production, along with the oxygen consumption, would be useful in understanding the full mechanism of what happens during particle inhalation. Furthermore, efficient monitoring of intracellular oxygen concentration is an important area of research that can provide insight as to cellular function and status. This leads into the second and main component of this research, creation of efficient optical oxygen with a novel matrix to prevent probe leaching and provide linear Stern-Volmer plots. The probe utilized is tris(2,2'-bipyridyl) ruthenium(II), and the matrix is siliceous zeolite-Y. The goal of this research was to improve the loading level of a sensor previously established in our research group then demonstrate the sensor's abilities in the following areas: (1) monitoring dissolved oxygen in solution via a glucose oxidase assay as an in situ measurement via emission quenching, (2) monitoring dissolved oxygen in macrophage cells during an oxidative burst via confocal microscopy, and (3) demonstrating the ability to immobilize the ruthenium loaded zeolite on the end of a fiber optic and discussing future optimization to improve the sensing parameters. The synthetic scheme utilized to load the tris(2,2'-bipyridyl) ruthenium(II) inside of the siliceous zeolite-Y supercages was altered by changing the ruthenium precursor and some of the experimental conditions to improve the loading level. The results showed an improved loading level of the ruthenium complex in the zeolite, which did not leach and gave linear Stern-Volmer plots during oxygen quenching experiments. In the realms of intracellular monitoring of dissolved oxygen as well as fiber optic sensing, parameters have been established demonstrating the working ability of the ruthenium loaded zeolite providing a basis for future optimization.
机译：本论文的研究集中在两个方面研究沸石体系。该研究的首要目标是检查导致羟基自由基相关毒性的颗粒性质。第二个目标是创建一种用于细胞内氧气监测的高效光学氧气传感器。众所周知，石棉会引起多种呼吸系统健康问题。但是，导致这些问题的确切机制尚不清楚。通常，石棉会参与Fenton化学反应，产生羟基自由基，从而导致体内毒性。在体内氧化应激的这段时间内，细胞内的氧气处于通量状态。能够监测细胞内的氧气浓度可以提供与细胞状况有关的关键信息。最初，进行的研究集中于Fenton化学和诸如矿物等石棉的氧化应激。研究人员正在努力阐明石棉毒性的确切机理，因为它已经导致并且仍然导致多种呼吸系统健康问题。导致呼吸系统健康问题的石棉的理化特性尚未完全定义。这项研究的目的是将颗粒毒性与理化特性相关联，以帮助最终阐明石棉毒性的机理。吸入石棉后，颗粒与含抗氧化剂的肺衬液发生相互作用。抗氧化剂具有还原石棉颗粒上三价铁的能力。然后，这些颗粒被巨噬细胞吞噬，随后引起氧化性爆发，以努力去除吸入的颗粒。在此氧化性爆裂期间，产生过氧化氢，诱导亚铁与Fenton化学反应。用具有类似于石棉的性质但毒性不同的矿物质模仿氧化爆发过程，可以提供与毒性有关的关键物理化学特征的深刻见解。将良性的铝硅酸盐丝光沸石和高度致癌的硅铝酸盐毛沸石进行铁离子交换，使其与抗氧化剂接触，然后与过氧化氢接触以引起氧化性破裂。监测羟基自由基的产生，确定矿物铝硅酸盐的物理化学性质之间的差异是否导致不同的Fenton活性。这项研究的结论是，矿物质表面上铁的配位对Fenton活性起着重要作用。在氧化爆发期间，细胞内出现了氧气通量。能够监测羟基自由基的产生以及氧气的消耗，对于理解颗粒吸入过程中发生的全部机理将很有用。此外，有效监测细胞内氧浓度是一个重要的研究领域，可以提供有关细胞功能和状态的见解。这导致了本研究的第二和主要内容，即创建具有新型基质的高效光学氧气，以防止探针浸出并提供线性Stern-Volmer图。使用的探针是三（2,2'-联吡啶基）钌（II），基质是硅质沸石-Y。这项研究的目的是提高以前在我们的研究小组中建立的传感器的负荷水平，然后证明该传感器在以下领域的能力：（1）通过葡萄糖氧化酶测定监测溶液中的溶解氧，作为通过发射的原位测量淬灭；（2）通过共聚焦显微镜在氧化爆发期间监测巨噬细胞中的溶解氧；（3）证明将钌负载沸石固定在光纤末端的能力，并讨论了改善传感参数的未来优化方法。通过改变钌前驱体和一些实验条件以提高负载水平，改变了将三（2,2'-联吡啶基）钌（II）加载到硅质沸石-Y超笼内的合成方案。结果表明，在氧猝灭实验中，钌络合物在沸石中的负载量有所提高，没有浸出，并给出了线性Stern-Volmer图。在细胞内溶解氧监测以及光纤传感领域，已经建立了参数，这些参数证明了负载钌的沸石的工作能力，为将来的优化提供了基础。

著录项

  • 作者

    Ruda, Toni Ann.;

  • 作者单位

    The Ohio State University.;

  • 授予单位 The Ohio State University.;
  • 学科 Chemistry Analytical.
  • 学位 Ph.D.
  • 年度 2007
  • 页码 246 p.
  • 总页数 246
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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