Modular Microfluidics as an Enhanced Bioanalytical Tool

描述（由申请人提供）：PI最近对文献的一般调查显示，2011-2012年发表了>1000篇涉及使用微流体技术的某种类型的细胞测定的文章。由于体内细胞功能最常受到其他细胞类型和组织的影响，因此微流体细胞测定的最近趋势是在单个装置上培养“器官”或其他组织类型。这样的装置将使细胞与细胞之间的通信能够在受控的体外平台上被监测。PI的团队已经用多种细胞类型进行了近十年的此类研究，并且直接了解制备此类装置的复杂性;例如，细胞固定和培养，试剂（刺激物，抑制剂等）的引入和流动，并且检测必须在单个设备上同时工作才能成功。如果一个失败了，整个装置必须报废，重新开始。在本申请中，PI将建立在他自己的团队和其他人最近的工作基础上，以创建一个模块化微流体系统，其中用于样品（细胞）注射，细胞扰动（这里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以及检测的区域都将在独立的组件或模块上进行，这些组件或模块可逆地密封在一起。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;可以简单地将失败的模块更换为另一个模块，并及时完成实验。PI将通过调查输血医学界目前面临的重要生物学问题来证明器械的实用性。具体来说，当患者接受红细胞输注时，体内产生的一氧化氮相应缺乏;因此，血流受到损害。目前，血库界的临床研究人员怀疑储存的红细胞是这些一氧化氮水平降低的罪魁祸首。PI及其团队将利用申报的模块化器械，通过评价红细胞对不同水平的低氧浓度（缺氧）的反应，证明红细胞确实在一氧化氮可用性中发挥作用。我们还将证明，这种反应的一个可能原因是血库界目前使用的解决方案，以收集和储存从献血者收集的血液。总之，PI认为当前的储存溶液使储存的红细胞对输血患者的缺氧条件无反应。这种对氧张力的反应降低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确认这一假设的一氧化氮在输血医学的可用性。因此，该提案的结果将在技术上和健康意义平台上产生很大影响。

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.