Grup de Sensors i Biosensors, Departament de Química, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.
Laboratori de Referència de Catalunya, Hospital del Mar, 08003, Barcelona, Spain.
Biosens Bioelectron. 2020 Feb 15;150:111882. doi: 10.1016/j.bios.2019.111882. Epub 2019 Nov 13.
Exosomes are nano-sized vesicles, which are currently under intensive study as potential diagnostic biomarkers for many health disorders, including cancer. This paper addresses the study of an electrochemical immunosensor in different formats for the characterization and quantification of exosomes derived from three breast cancer cell lines (MCF7, MDA-MB-231 and SKBR3). To achieve that, the exosomes were preconcentrated from cell-culture supernatant (and eventually in human serum) on magnetic particles modified with antibodies against the general tetraspanins CD9, CD63 and CD81, as well as specific receptors of cancer (CD24, CD44, CD54, CD326 and CD340). The electrochemical immunosensor is able to reach a limit of detection of 10 exosomes μL directly in human serum, when performing the immunomagnetic separation with antiCD81 modified magnetic particles and the labeling based on CD24 and CD340 as cancer-related biomarker, avoiding the interference from free receptors in the serum matrix. Furthermore, the electrochemical immunosensor shows reliable results for the differentiation of healthy donors and breast cancer individuals based on specific epithelial biomarkers. This approach is a highly suitable alternative method for the detection of exosomes in scarce resource settings.
外泌体是纳米大小的囊泡，目前作为许多健康障碍（包括癌症）的潜在诊断生物标志物受到广泛研究。本文研究了一种电化学免疫传感器的不同形式，用于表征和定量来自三种乳腺癌细胞系（MCF7、MDA-MB-231 和 SKBR3）的外泌体。为此，将外泌体从细胞培养上清液（最终是人血清）中通过与针对通用四跨膜蛋白 CD9、CD63 和 CD81 以及癌症特异性受体（CD24、CD44、CD54、CD326 和 CD340）的抗体修饰的磁性颗粒进行预浓缩。当使用抗 CD81 修饰的磁性颗粒进行免疫磁分离并基于 CD24 和 CD340 进行标记作为癌症相关生物标志物时，电化学免疫传感器能够在人血清中直接达到 10 个外泌体 μL 的检测限，从而避免了血清基质中游离受体的干扰。此外，电化学免疫传感器基于特定的上皮生物标志物，能够可靠地区分健康供体和乳腺癌个体。这种方法是在资源匮乏的情况下检测外泌体的一种非常合适的替代方法。
