Single rare cell assays and biomarkers detection using microfluidic nanotechnology

微流体纳米技术被用于实现两种研究流：(1)对单个稀有细胞进行信息丰富的分析，(2)对生物标志物（如核酸和蛋白质）进行高通量微阵列分析。STREAM 1是使用单细胞芯片来识别和测量包含在纳升大小的细胞保留腔中的单个肿瘤细胞。测量数据可为疾病的早期诊断和治疗期间的预后提供信息。血液样本中发现的循环肿瘤细胞（CTCs）等细胞是罕见的。我们的单细胞生物芯片能够测量稀有细胞的多种细胞参数，如细胞大小、细胞内药物浓度和多药耐药（MDR）的细胞表面生物标志物。我们将使用MDR抑制剂对多个单细胞进行药物积累测量，以增强积累；我们期望将这些测量结果与基于免疫测定的MDR生物标志物测定相关联。有或没有MDR抑制剂的单个癌细胞上药物积累的测量数据可以为有效的化疗提供信息，例如使用适当的药物抑制剂组合。STREAM 2是对DNA和蛋白质生物标志物进行高通量诊断分析。分析将在用于真菌病原体检测的微流控微阵列（MMA）芯片上进行。我们提出在MMA芯片上检测DNA生物标志物，并利用金纳米颗粒增强检测特异性。其中一个应用是检测与鲑鱼健康有关的疾病。MMA芯片还用于分析人类血清样本中的蛋白质生物标志物，用于疾病检测和治疗。我们也将进行微流控液体流动过程的计算机模拟研究，以实现高效的试剂/样品输送。单个稀有细胞测定和MMA两种平台都适合合并到护理点（POC）系统中。所有项目的新颖之处都涉及在这些微流体装置中有效地控制固有的低液体体积（亚纳升），从而需要更少的起始材料，产生更少的废物，符合绿色化学的概念。

The microfluidics nanotechnology is employed to enable two streams of research: (1) information-rich assays on single rare cells, and (2) high-throughput microarray-based assays for biomarkers (e.g. nucleic acids and proteins). STREAM 1 is to use a single cell chip to identify and measure single tumor cells contained within a nanolitre-sized cell retention chamber. The measured data may provide information for early disease diagnosis and for prognosis during treatment. Cells such as circulating tumor cells (CTCs) found in blood samples are rare. Our single cell biochip is able to measure a rare cell for multiple cellular parameters, such as cell size, intracellular drug concentration, and cell surface biomarker for multidrug resistance (MDR). We will perform drug accumulation measurements on multiple single cells using MDR inhibitors in order to enhance accumulation; we expect to correlate these measurement results with the immunoassay-based MDR biomarker determination. The measured data of drug accumulation on a single cancer cell with or without the MDR inhibitor may provide information for effective chemotherapy such as the use of the appropriate drug-inhibitor combination. STREAM 2 is to conduct analysis of DNA and proteins biomarkers for high throughput diagnosis. The analysis will be conducted on a microfluidic microarray (MMA) chip developed for fungal pathogen detection. We propose to detect DNA biomarkers on the MMA chip, and to increase detection specificity enhanced by using gold nanoparticles. One application is to detect diseases related to salmon health. The MMA chip is also employed to analyze protein biomarkers in human serum samples for disease detection and treatment. We will also perform computer simulation study of the microfluidic liquid flow process for efficient reagent/sample delivery. Both platforms on single rare cell assays and MMA are suitable for incorporation in point-of-care (POC) systems. The novelty of all projects involves the efficient manipulation of inherently low liquid volumes (in sub-nanolitre) within these microfluidic devices, thus demanding less starting materials and generating less wastes, conforming to the notion of green chemistry.