State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
Department of Clinical Laboratory, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, China.
Lab Chip. 2019 Sep 7;19(17):2897-2904. doi: 10.1039/c9lc00445a. Epub 2019 Jul 31.
Extracellular vesicles (EVs), involved in many diseases and pathophysiological processes, have emerged as potential biomarkers for cancer diagnosis. However, efficient isolation and detection of EVs still remain challenging. Here, we report an integrated chip for isolation of EVs with a double-filtration unit and ultrasensitive detection using photonic crystal (PC) nanostructure. Nanofiltration membranes were integrated into the device to isolate and enrich the EVs of 20-200 nm in size based on size-exclusion. Then, CD63 aptamers were used to combine the EVs on the nanofiltration membrane with a pore size of 20 nm, and excess aptamers passed through the membrane to bind with CD63 immobilized on the PC nanostructure. Benefitting from the fluorescence enhancement effect of the PC nanostructure in competition assays, the EVs could be quantified sensitively by analyzing the concentration of excess aptamers. Due to the high sensitivity, the limit of detection was as low as 8.9 × 10 EVs per mL with a low sample consumption of only 20 μL. Furthermore, serum samples from breast cancer patients and healthy donors could be successfully distinguished. Thus, this microfluidic chip provides an effective method for pre-screening of cancer in clinical samples.
细胞外囊泡（EVs）参与多种疾病和病理生理过程，已成为癌症诊断的潜在生物标志物。然而，EVs 的高效分离和检测仍然具有挑战性。在这里，我们报告了一种用于 EV 分离的集成芯片，该芯片具有双过滤单元和使用光子晶体（PC）纳米结构的超灵敏检测。将纳米滤膜集成到设备中，基于尺寸排阻，分离和浓缩 20-200nm 大小的 EVs。然后，使用 CD63 适体将 20nm 孔径的纳米滤膜上的 EVs 结合，多余的适体通过膜与固定在 PC 纳米结构上的 CD63 结合。受益于竞争分析中 PC 纳米结构的荧光增强效应，通过分析多余适体的浓度可以灵敏地定量 EVs。由于灵敏度高，检测限低至 8.9×10 EVs/mL，样品消耗量仅为 20μL。此外，成功区分了乳腺癌患者和健康供体的血清样本。因此，这种微流控芯片为临床样本中的癌症预筛查提供了一种有效的方法。
