Modular Microfluidics as an Enhanced Bioanalytical Tool

描述（由申请人提供）：PI最近对文献的总体调查显示，2011-2012年已发表的bb101000篇文章涉及使用微流体技术的某种类型的细胞测定。由于体内的细胞功能最常受到其他细胞类型和组织的影响，微流控细胞分析的最新趋势是在单个设备上研究“器官”或其他组织类型。这种装置将使细胞间的通信能够在受控的体外平台上被监测。近十年来，PI的团队一直在用多种细胞类型进行这样的研究，并且第一手了解准备这种设备的复杂性；例如，细胞固定和培养，试剂（刺激，抑制剂等）的引入和流动，以及检测都必须在单个设备上同时工作才能成功。如果其中一个出现故障，整个设备必须报废并重新开始。在这个应用中，PI将建立在他自己的小组和其他人最近的工作基础上，创建一个模块化的微流体系统，在这个系统中，样品（细胞）注射、细胞扰动（这里是红细胞暴露于不同氧浓度的区域）、与其他细胞类型的相互作用和检测都将在单独的组件或模块上进行，这些组件或模块彼此可逆密封。重要的是，如果有多个模块可用（例如，多个细胞生长模块在培养箱中生长），一个模块的失败并不意味着实验结束；失败的模块可以简单地交换到另一个模块，实验将及时完成。PI将通过调查输血医学界目前面临的一个重要的生物学问题来展示设备的实用性。具体来说，当患者接受红细胞输血时，体内产生的一氧化氮相应缺乏；因此，血液流动受到损害。目前，血库界的临床研究人员怀疑，储存的红细胞是导致一氧化氮水平降低的罪魁祸首。PI和他的团队将利用提出的模块化设备，通过评估红细胞对不同水平的氧浓度降低（缺氧）的反应，来证明红细胞确实在一氧化氮的可用性中发挥作用。我们还将证明，造成这种反应的一个可能原因是血库界目前使用的收集和储存献血者血液的解决方案。总之，PI认为目前的储存方案使储存的红细胞对输血患者的缺氧条件没有反应。这种对氧紧张反应的减弱导致一氧化氮的减少和血流量的总体减少以及其他输血后并发症的增加。本文提出的微流控装置的发展将有助于证实输血医学中一氧化氮可用性的假设。因此，这一提议的结果将在技术上和健康意义平台上产生重大影响。

DESCRIPTION (provided by applicant): A recent general survey of the literature by the PI showed that >1000 articles had been published in 2011-2012 involving some type of cellular assay using microfluidic technologies. Because cellular function in vivo is most often affected by other cell types and tissues, a recent trend in microfluidic cellular assays has been to investigat "organs" or other tissue types on a single device. Such devices will enable cell to cell communication to be monitored on a controlled, in vitro platform. The PI's group has been performing such studies with multiple cell types for nearly a decade now and knows first-hand the complexity of preparing such a device; for example, cell immobilization and culture, introduction and flow of reagents (stimuli, inhibitors, etc.), and detection must all work simultaneously on a single device for success. If one fails, the entire device must be scrapped and began anew. In this application, the PI will build upon recent work by his own group, and others, to create a modular microfluidic system whereby areas for sample (cell) injection, cell perturbation (here red blood cell exposure to regions of varying oxygen concentration), interaction with other cell types, and detection will all be performed on separate components, or modules, that are reversibly sealed to each other. Importantly, if multiple modules are available (e.g., multiple cell growth modules growing in an incubator), failure by one module doesn't mean the experiment is over; that failed module can simply be exchanged for another module and the experiment moves to completion in a timely manner. The PI will demonstrate device utility by investigating an important biological problem currently facing the transfusion medicine community. Specifically, when patients receive a transfusion of red blood cells, there is a corresponding lack of nitric oxide produced in vivo; thus, blood flow is compromised. It is currently suspected by clinical researchers in the blood banking community that the stored red blood cell is the culprit of these reduced nitric oxide levels. The PI and his group will utilize te proposed modular device to demonstrate that the red blood cell does indeed play a role in nitric oxide availability by evaluating red cell response to varying levels of reduced oxygen concentrations (hypoxia). We will also demonstrate that one possible reason for this response is the current solutions being used by the blood banking community to collect and store blood collected from donors. In summary, the PI believes the current storage solutions are rendering the stored red cells non-responsive to hypoxic conditions in the transfusion patient. This reduced response to oxygen tensions is resulting in a decrease in nitric oxide and an overall reduction in blood flow and increase in other post-transfusion complications. The development of the microfluidic device proposed here will facilitate confirmation of this hypothesis about nitrc oxide availability in transfusion medicine. Thus, results from this proposal will be high impact both technologically and from a health-significance platform.