Nitric Oxide Microfluidic Sensor

描述(由申请人提供)：这个小型企业创新研究(SBIR)第一阶段项目旨在开发一种基于微流控的一氧化氮(NO)传感器，作为早期脓毒症风险评估设备。脓毒症对美国医疗体系造成巨大压力，由于住院时间延长，每年消耗超过170亿美元，并导致严重的发病率和死亡率。快速诊断和干预是改善患者预后的关键。不幸的是，目前诊断败血症的方法依赖于对症状(例如发烧和心率不齐)的检测，而这些症状只有在感染进展到危险水平(晚期脓毒症)后才会变得明显。该项目的目标是：1)制造用于测量抽血中NO水平的微型微流控传感器的原型；以及2)确定NO检测在临床前、单微生物肺脓毒症模型中的潜在临床应用价值。使用间接分析方法，文献研究发现，由于脓毒症，血液中一氧化氮显著升高(&gt；10倍基础)。然而，缺乏快速和直接的NO传感器阻碍了将这些发现转化到临床上。在猪多菌败血症模型中的初步研究表明，这种微流控NO传感器可以代表一种新的范式，用于诊断早期脓毒症和挽救生命。这一发现得到了体外研究的支持，该研究表明，巨噬细胞会对细菌做出反应，释放NO，并随着细菌负荷的增加而增加。通过拟议的研究，我们将开发一种新颖的、微型化的NO传感平台，以实现对小等份血液中这一生物标志物的快速测量。在满足该设备的特定分析性能要求(对NO的灵敏度和选择性、线性响应范围、重复性等)后，我们将确定NO测量在已建立的肺脓毒症临床前模型中的预测价值。大多数脓毒症的体内NO研究都是在多菌模型中进行的，如盲肠结扎和穿孔(CLP)。虽然这种模式忠实地概括了破裂的阑尾炎，但微生物环境比大多数医院获得性感染要复杂得多(即大多数与导管相关的感染和医院获得性肺炎病例都有单一的病原体)。临床肺炎和临床前肺炎的小鼠模型都有共同的免疫炎症成分，与CLP相比，具有高度的重复性和可滴定性。这些模型将允许测试几个具有临床意义的参数，包括：1)区分革兰氏阳性和革兰氏阴性感染的血液一氧化氮反应，2)确定体内的一氧化氮反应是否与微生物负荷成正比，以及3)筛选常用的治疗方法(例如，疼痛控制和抗生素)，以评估它们对感染后血液一氧化氮反应的影响。这些研究将为临床受试者评估血液一氧化氮传感器建立关键参数。

DESCRIPTION (provided by applicant): This Small Business Innovation Research (SBIR) Phase I project aims to develop a microfluidic-based nitric oxide (NO) sensor as an early sepsis risk assessment device. Sepsis causes significant strain on the U.S. healthcare system, consuming over $17 billion annually due to extended hospital stays, and significant morbidity and mortality. Rapid diagnosis and intervention are critical to improve patient outcomes. Unfortunately, current methods of diagnosing sepsis rely on the detection of symptoms (e.g., fever and irregular heart rate) that only become evident after the infection has progressed to dangerous levels (advanced sepsis). The goals of this project are to: 1) manufacture prototype miniaturized microfluidic sensors for the measurement of NO levels in drawn blood; and, 2) determine the potential clinical utility of NO determination in preclinical, monomicrobial models of pulmonary sepsis. Using indirect analysis methods, literature studies have found significant elevations (>10x basal) in blood nitric oxide due to sepsis. However, the lack of a rapid and direct sensor for NO has frustrated the translation of these findings to the clinic. Initial studie in a porcine model of polymicrobial sepsis have shown that this microfluidic NO sensor can represents a new paradigm for diagnosing early sepsis and saving lives. This finding is supported by in vitro studies showing that macrophages release NO in response to bacteria, with increasing magnitude according to bacteria load. Through the proposed studies we will develop a novel, miniaturized NO sensing platform to enable the rapid measurement of this biomarker in small aliquots of blood. After meeting specific analytical performance requirements for this device (sensitivity and selectivity for NO, linear response range, reproducibility, etc.),we will determine the predictive value of NO measurement in established preclinical models of pulmonary sepsis. Most in vivo studies of NO in sepsis have been performed in polymicrobial models such as cecal ligation and puncture (CLP). While this model faithfully recapitulates ruptured appendicitis, the microbiological milieu is more complex than most hospital-acquired infections (i.e., most catheter-related infections and cases of hospital-acquired pneumonia have a single etiologic agent). Both clinical pneumonia and the preclinical, murine models of pneumonia share common immunoinflammatory elements and, in contrast to CLP, are highly reproducible and titratable. These models will allow testing of several clinically significant parameters, including: 1) differentiating the blood nitric oxide response in Gram- positive and Gram-negative infections, 2) determining whether the in vivo nitric oxide response is proportional to microbial burden, and 3) screening commonly used therapeutic modalities (for example, pain management and antibiotics) to assess their affects on the blood nitric oxide response to infection. These studies will establish key parameters for the evaluation of the blood nitric oxide sensor in clinical subjects.