Ultra-sensitive magnetic assays for rapid detection of stroke biomarkers

描述(由申请人提供)：MagneSensors公司第一阶段用于快速检测中风生物标志物的SBIR超灵敏磁性分析项目摘要目前中风的治疗因需要快速确定谁可以安全地从治疗干预中受益而受到阻碍。FDA批准的溶栓疗法可以有效地治疗最常见的中风-急性缺血性中风，只要在最初的3-4.5小时内使用。许多医生不愿使用溶栓疗法，因为如果对脑出血(ICH)患者进行溶栓治疗可能是致命的。对血液中的中风生物标志物进行快速而简单的诊断测试可能会提供有价值的诊断信息，有助于区分哪些人应该接受治疗，哪些不应该接受治疗。大量研究表明，胶质纤维酸性蛋白(GFAP)是一种很有前途的生物标志物。不幸的是，现有的GFAP检测缺乏足够的敏感性，变数很大(不是直接定量的)，而且耗时太长。因此，它们甚至不适合用于评估生物标记物的临床研究，也不适合随后的临床应用。我们推测，快速、灵敏和定量的GFAP血液检测可以为特定的临床应用提供重要的诊断信息，包括排除 我也是。我们的第一阶段目标是开发这样一种测试，以克服现有测试的缺点。我们提出了一种新的方法，以使用新的磁性纳米颗粒标签和超灵敏磁性传感器为中心，它们共同提供了独特的好处组合。据我们所知，磁检测分析从未被应用于中风生物标志物的检测。第一阶段的具体目标是展示一种GFAP中风生物标志物的磁性免疫分析方法，它具有：1)高分析灵敏度，血液中含量为2 pg/ml，2)快速周转时间，包括准备和测量，总共50分钟。我们还将测量UCSD卒中中心合作者从缺血性卒中和脑出血患者收集的30份临床血液样本中GFAP的水平。第一阶段GFAP磁性测试的开发将采用一种模型系统，将GFAP添加到全血中，并将其捕获在涂有抗GFAP的微球上。包被检测抗GFAP抗体的磁性纳米颗粒然后结合到捕获的GFAP上。结合磁性纳米颗粒标签的磁性信号是用我们最新一代的磁性检测仪测量的，该仪器是为临床环境而设计的。新的“混合和测量”格式消除了去除未结合的磁性纳米颗粒标签或红细胞的洗涤步骤的需要，从而使血液生物标志物的快速和灵敏测试成为可能。在第二阶段，我们计划对加州大学圣迭戈分校合作者提供的标本进行更大规模的前瞻性临床研究。我们希望将总测试时间减少到15分钟或更少，这对这一时间关键型应用程序非常重要。我们还计划评估更多的生物标志物，以提高临床敏感性和特异性。第二阶段的目标是收集令人信服的数据，招募更多的发光站点，以支持第三阶段的多中心临床研究。最终，我们计划与一家更大的公司合作，将这些测试推向市场。 公共卫生相关性：美国每年有近80万人中风，导致14万人死亡，使中风成为导致死亡的第三大原因和导致长期残疾的第一大原因。经过验证的治疗方法如果及时给予，可以显著减少对脑细胞的损害，但目前它的利用不足，因为很难快速确定何时最安全地使用它。快速、灵敏地检测血液中的卒中生物标志物有助于早期诊断，提高患者的治疗水平。

DESCRIPTION (provided by applicant): MagneSensors, Inc. Phase I SBIR Ultra-sensitive magnetic assays for rapid detection of stroke biomarkers Project Summary Current treatment of stroke is hampered by the need to rapidly determine who can safely benefit from therapeutic intervention. FDA approved thrombolytic therapy can be effective for acute ischemic stroke, the most common stroke, as long as it is administered within the first 3-4.5 hours. Many doctors are reluctant to use thrombolytic therapy since it can be lethal if administered to patients with intracerebral hemorrhage (ICH). A rapid and simple diagnostic test for stroke biomarkers in blood might provide valuable diagnostic information, helping to sort out who should and should not receive therapy. A number of studies have shown glial fibrillary acidic protein (GFAP) to be a promising biomarker. Unfortunately, existing GFAP tests lack adequate sensitivity, are highly variable (not directly quantitative), and take too long. As such, they are inadequate even for clinical studies designed to evaluate the biomarker as well as unsuitable for subsequent clinical application. We hypothesize that a rapid, sensitive, and quantitative blood test for GFAP could provide important diagnostic information for specific clinical applications that include ruling out ICH. Our Phase I goal is to develop such a test to overcome the shortcomings of existing tests. We propose a new approach that is centered on the use of new magnetic nanoparticle labels and ultra-sensitive magnetic sensors, which together offer a unique combination of benefits. To our knowledge, magnetic detection assays have never been applied to the detection of stroke biomarkers. The Phase I specific aim is to demonstrate a magnetic immunoassay for the GFAP stroke biomarker that has: 1) high analytical sensitivity, 2 pg/ml in blood, and 2) rapid turnaround time, 50 minutes total that includes both preparation and measurement. We will also measure GFAP levels in thirty clinical blood specimens collected from ischemic stroke and ICH patients by our UCSD Stroke Center collaborator. The development of the GFAP magnetic test in Phase I will employ a model system where GFAP is spiked into whole blood and captured on microspheres coated with anti-GFAP. Magnetic nanoparticles coated with detect anti-GFAP antibodies then bind to the captured GFAP. The magnetic signal from bound magnetic nanoparticle labels is measured with our latest generation magnetic detection instrument, which is designed for use in a clinical setting. The novel "mix and measure" format eliminates the need for wash steps to remove unbound magnetic nanoparticle labels or red blood cells, thereby enabling rapid and sensitive tests of blood biomarkers. In Phase II we plan to conduct a much larger prospective clinical study on specimens provided by our UCSD collaborator. We expect to reduce the total test time to 15 minutes or less, which is very important for this time critical application. We also plan to evaluate additional biomarkers to improve clinical sensitivity and specificity. The Phase II goal is to collect convincing data to recruit additional luminary sites t enable multi-center clinical studies in Phase III. Ultimately, we plan to team with a larger company to bring these tests to market. PUBLIC HEALTH RELEVANCE: Nearly 800,000 people have strokes annually in the U.S. leading to 140,000 deaths, making stroke the third leading cause of mortality and the number one cause of long term disability. Proven therapy can significantly reduce damage to brain cells if given in time, but it is currently underutilized as it is difficult to quickly determine when itcan most safely be used. The rapid, sensitive detection of stroke biomarkers in blood could assist early diagnosis to improve patient treatment.