Microfluidic Device for Isolating Rare Blood Cells

描述（由申请人提供）：从外周血中分离稀有细胞是癌症诊断和治疗中一个困难而繁琐的步骤。这方面的例子包括与白血病相关的白细胞、可作为实体瘤治疗替代标志物的循环内皮细胞，以及可作为诊断和预后工具的循环癌细胞。在大多数患者中，每一种类型的细胞都比红细胞多至少1000倍。因此，从全血样本中分离这些细胞是许多临床和基础研究分析所需的第一步。我们最近描述了一种微流体装置，它利用血浆脱脂和白细胞边沿-微循环中血流的固有特征-直接从全血中富集有核细胞，如白细胞。它由一个简单的矩形微通道网络组成，使用标准光刻和硅树脂成型技术制造，只需要压力驱动流来操作。它的初始通道旨在增强球形细胞的横向迁移，一旦靠近壁面，很容易通过小的提取通道提取。在我们的初步设计中，单次通过该装置可使白细胞与红细胞的比例增加34倍。我们建议进一步发展微流体，以提供简单、高效和廉价的技术，作为芯片实验室分析的初始阶段。将其集成到需要稀有细胞富集的微量分析设备中，将提供更便宜、更可靠的临床分析，并且方便便携，可用于即时检测。具体而言，我们将最大限度地提高有核血细胞分离的纯度和效率，并将其性能与传统分离技术进行比较。当完全开发时，这项技术将成为任何微流控装置分析有核血细胞群的必要和不可或缺的组成部分，消除了对初步血液处理步骤的需要。

DESCRIPTION (provided by applicant): Isolation of rare cells from peripheral blood is a difficult and tedious step in the diagnosis and treatment of cancer. Examples include leukocytes, which are of interest in leukemia, circulating endothelial cells, which can serve as a surrogate marker for solid tumor treatment, and circulating cancer cells, which may provide a tool for diagnosis and prognosis. In most patients, each of these cell types is outnumbered by red blood cells by a factor of at least 1000. Therefore, isolation of these cells from a sample of whole blood is the required first step of many clinical and basic research assays. We recently described a microfluidic device that takes advantage of plasma skimming and leukocyte margination - intrinsic features of blood flow in the microcirculation - to enrich nucleated cells such as leukocytes directly from whole blood. It consists of a simple network of rectangular microchannels manufactured using standard photolithography and silicone molding techniques, and requires only pressure-driven flow to operate. Its initial channel is designed to enhance lateral migration of spherical cells, which, once near the wall are easily extracted through small extraction channels. In our preliminary design, a single pass through the device produces 34-fold enrichment of the leukocyte-to-erythrocyte ratio. We propose to further develop the microfluidics to provide simple, efficient and inexpensive technology for use as an initial stage in lab-on-a-chip analyses. Its integration into microanalytical devices that require rare cell enrichment will provide less expensive, more reliable, clinical assays that are also convenient and portable for point-of-care testing. Specifically, we will maximize the purity and efficiency of nucleated blood cell isolation and compare the performance with traditional separation techniques. When fully-developed, this technology will be a necessary and integral component of any microfluidic device analyzing nucleated blood cell populations by eliminating the need for preliminary blood processing steps.