PA22176, SBIR, Phase I, Lateral Flow Assay to Detect Malaria

摘要/摘要 疟疾是一种通过蚊子叮咬传播的致命疾病。每年，数以百万计的人在发展中国家 一些地区受到这种疾病的影响。5岁以下的儿童最容易感染疟疾。已经取得了长足的进步 旨在开发预防和治疗疟疾的疫苗和药物。每年死于疟疾的人数 在过去的100年里减少了大约85%。也就是说，疟疾仍在78个国家流行。 进一步根除这种疾病的最大挑战之一是检测亚临床/无症状 感染，特别是在发展中世界的广大农村地区。聚合酶链式反应或LAMP等分子方法 化验可以检测到这些感染，但它们需要最适合 实验室环境。便携式快速抗原检测通常非常适合在偏远地区使用，但它们 缺乏检测许多低度感染所需的敏感度。最近的报告表明，快速抗原测试 在同一样本上使用LAMP检测确定的亚临床病例中，有高达98%的病例被漏掉。此外，许多疟疾 测试需要大量的样品准备，这在偏远地区是非常困难的。 该项目的总体目标是创建一种坚固、便携的侧向流动检测方法来检测疟疾。这些类型的 分析非常适合现场使用，因为它们不需要设备，而且具有简单的可视读数。 我们的测试将使用特殊设计的样本垫和盒式磁带设计来处理血液样本 设备-此功能不需要在现场进行复杂的样品准备。不同于当前的快速 基于抗体/抗原相互作用的诊断，我们的检测使用了一种疟疾生物标志物(称为血球蛋白)。 来创造一个视觉信号。我们的测试使用血球蛋白中的铁原子来催化金的标记 纳米粒子。我们的催化反应方案可以从每个分析物中产生许多标记的颗粒，从而 产生强大的信号放大。信号放大将极大地提高系统的检测灵敏度 我们的设备比较了其他快速诊断测试，并允许检测低水平的亚临床感染 菲尔德。我们相信，我们独特的横向流动分析设备将是正在进行的斗争中的重要工具 根除疟疾。 具体目标#1：建立一种检测血球蛋白的侧向流动试验。 具体目标2：开发一种集成的侧向流动分析设备来处理血液样本并进行 测试。 具体目标#3：使用一种新的基于血球蛋白的侧向流动分析检测全血中的感染细胞。

Summary/Abstract Malaria is a deadly disease transmitted by mosquito bites. Every year, many millions of people in developing areas are affected by this disease. Children under 5 are most vulnerable to malaria. Great strides have been made to develop vaccines and medicines to prevent and treat malaria. The number of annual malaria deaths has decreased by about 85% in the past 100 years. This said, malaria is still endemic in 78 countries. One of the great challenges to further eradication of this disease is detection of subclinical/asymptomatic infections, especially in large rural areas in the developing world. Molecular methods such as PCR or LAMP assays can detect these infections, but they require equipment and expertise which are best suited to the laboratory environment. Portable rapid antigen tests are generally well suited for use in remote areas, but they lack the required sensitivity to detect many low-level infections. Recent reports indicate that rapid antigen tests miss up to 98% of the subclinical cases identified using a LAMP assay on the same samples. Also, many malaria tests require extensive sample prep which is very difficult to perform in remote locations. The overall goal of this project is to create a rugged, portable lateral flow assay to detect malaria. These types of assays are well suited for field use because they do not require equipment and have a simple visual readout. Our test will use specially-engineered sample pads and cassette design to process blood samples within the device - this feature eliminates the need for complicated sample prep in the field. Unlike current rapid diagnostics based on antibody/antigen interactions, our assay utilizes a malarial biomarker (called hemozoin) to create a visual signal. Our test uses the iron atoms within the hemozoin to catalyze the labeling of gold nanoparticles. Our catalytic reaction scheme can generate many labeled particles from each analyte, thereby creating strong signal amplification. The signal amplification will greatly improve the detection sensitivity of our device compared other rapid diagnostic tests and permit detection of low-level subclinical infections in the field. We believe that our unique lateral flow assay device will be an important tool in the ongoing fight to eradicate malaria. Specific Aim #1: Construct a lateral flow test to detect hemozoin. Specific Aim #2: Develop an integrated lateral flow assay device to process blood samples and perform the test. Specific Aim #3: Detect infected cells in whole blood using a novel hemozoin-based lateral flow assay.