Centre for Personalised Nanomedicine, Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland , Corner College and Cooper Roads (Building 75), Brisbane, Queensland 4072, Australia.
Anal Chem. 2014 Nov 18;86(22):11125-32. doi: 10.1021/ac502082b. Epub 2014 Oct 31.
Exosomes show promise as noninvasive biomarkers for cancer, but their effective capture and specific detection is a significant challenge. Herein, we report a multiplexed microfluidic device for highly specific capture and detection of multiple exosome targets using a tunable alternating current electrohydrodynamic (ac-EHD) methodology, referred to as nanoshearing. In our system, electrical body forces generated by ac-EHD act within nanometers of an electrode surface (i.e., within the electrical layer) to generate nanoscaled fluid flow that enhances the specificity of capture and also reduce nonspecific adsorption of weakly bound molecules from the electrode surface. This approach demonstrates the analysis of exosomes derived from cells expressing human epidermal growth factor receptor 2 (HER2) and prostate specific antigen (PSA), and is also capable of specifically isolating exosomes from breast cancer patient samples. The device also exhibited a 3-fold enhancement in detection sensitivity in comparison to hydrodynamic flow based assays (LOD 2760 exosomes/μL for ac-EHD vs LOD 8300 exosomes/μL for hydrodynamic flow; (n = 3)). We propose this approach can potentially have relevance as a simple and rapid quantification tool to analyze exosome targets in biological applications.
外泌体有望成为癌症的非侵入性生物标志物，但有效捕获和特异性检测仍然是一个重大挑战。本文报告了一种基于可调谐交流电动力学（ac-EHD）方法的多重微流控装置，用于使用纳米剪切力高度特异性地捕获和检测多种外泌体靶标。在我们的系统中，ac-EHD 产生的电体力作用于电极表面的纳米级范围内（即，在电层内），以产生纳米级流体流动，从而提高捕获的特异性，并减少来自电极表面的弱结合分子的非特异性吸附。该方法证明了对表达人类表皮生长因子受体 2 (HER2)和前列腺特异性抗原 (PSA) 的细胞衍生的外泌体的分析，并且还能够特异性地从乳腺癌患者样本中分离出外泌体。与基于流体动力学的测定相比，该装置的检测灵敏度提高了 3 倍（ac-EHD 的 LOD 为 2760 个外泌体/μL，而流体动力学的 LOD 为 8300 个外泌体/μL；(n = 3)）。我们提出，这种方法可能具有相关性，可以作为一种简单快速的定量工具，用于分析生物应用中外泌体靶标。
