MICRODEVICES FOR MEASURING CPB SYSTEMIC INFLAMMATION

描述(申请人提供)：一些研究表明心脏手术会引起全身炎症反应，特别是在使用体外循环(CPB)的情况下。体外循环可诱导以补体、中性粒细胞和血小板活化为特征的复杂炎症反应，并释放促炎细胞因子。大量证据表明，全身炎症会导致许多术后并发症，包括可能导致多器官衰竭甚至死亡的重要器官功能障碍。炎症反应的强度似乎与CPB相关发病率的严重程度直接相关。由于缺乏对炎症反应(补体、中性粒细胞、单核细胞、血小板活化和促炎细胞因子的释放)的及时测量，限制了临床干预炎症反应的能力，甚至研究CPB的炎症反应。预期使用这里描述的设备对细胞因子和补体浓度的产生的实时测量将与通过传统的ELISA技术获得的测量相关联。更即时的测量将有助于了解细胞激活的机制，并修改手术和灌流方案，以最大限度地减少体外循环的不良影响。这项拟议的研究旨在开发一种新的方法，在微流控分析系统中以连续实时的方式测量血浆细胞因子和补体浓度，用于在线监测CPB过程中的炎症反应。该微系统包括血浆自动分离装置和用于连续测量的新型微量免疫分析。测量方法将使用微制造技术来创建携带血液的流体电路，并将在使用捐赠者血液的体外模拟体外循环程序中进行评估。微量免疫分析的基础是控制免疫分析微珠的运动，这些微球将通过一系列流动流，包括具有随时间变化的细胞因子和补体浓度的感兴趣的血浆样本、洗涤液、二次抗体溶液和检测区。将对两个设计进行评估。第一种设计使用磁珠，其运动由磁场控制在流动流之间传递，而第二种设计使用专门设计的流动结构，允许珠子在不同的流动流之间传递，而不需要混合或稀释。

DESCRIPTION (provided by applicant): Several studies have shown that cardiac surgery induces systemic inflammatory responses, particularly when cardiopulmonary bypass (CPB) is used. CPB induces complex inflammatory responses characterized by complement, neutrophil, and platelet activation, and the release of pro-inflammatory cytokines. Considerable evidence suggests that systemic inflammation causes many postoperative complications, including vital organ dysfunction that can lead to multi-organ failure and even death. The intensity of the inflammatory response appears to be directly correlated with the severity of CPB-related morbidity. The ability to clinically intervene in inflammation, or even study the inflammatory response to CPB, is limited by the lack of timely measurements of inflammatory responses (complement, neutrophil, monocyte, platelet activation, and the release of pro-inflammatory cytokines). It is anticipated that real-time measurement of the production of cytokine and complement concentration using the devices as described herein will correlate with measurements obtained by the conventional ELISA technique. More immediate measurements will aid in understanding the mechanisms of cellular activation, and modify surgical and perfusion protocols for minimizing the adverse effects of cardiopulmonary bypass. The proposed study is designed to develop a novel approach to measuring plasma cytokine and complement concentrations in a continuous real-time fashion within a microfluidic analytical system for online monitoring of inflammatory responses during CPB procedures. The microsystem includes a plasma autoseparation device and a novel microimmunoassay for continuous measurements. The measurement methods will use microfabrication technology to create blood carrying fluidic circuits and will be evaluated in a ex-vivo simulated cardiopulmonary bypass procedure with donor human blood. The microimmunoassay is based upon controlling the movements of immunoassay beads that will be passed through a series of flow streams including the plasma sample of interest with time varying cytokine and complement concentrations, washing solutions, secondary antibody solutions and a detection zone. Two designs will be evaluated. The first design uses magnetic beads whose movement is controlled by a magnetic field to pass between flow streams, while the second design uses a specially designed flow structure to allow the beads to pass between different flow streams without mixing or dilution.