Multiplexed phenotypic profiling of single extracellular vesicles for early clinical diagnosis of high-grade serious ovarian carcinoma

Liquid biopsy based early detection of cancer is full of challenges mainly attributing to the lack of specific biomarkers and effective techniques. Extracellular vesicles (EVs) are demonstrated to be emerging biomarkers for early cancer detection. Due to their nanoscale size and heterogeneity induced by distinct biogenesis, the analysis of EVs in single vesicle level is still challenging. Here we develop a single EV detection assay on a fluorescence-microfluidic chip (SEAFM) to probe phenotype changes of single EVs for early detection of cancer, with specific focus on high-grade serous ovarian carcinoma (HGSOC) which has the highest mortality rate among malignant tumors in gynecology. The designed microfluidic chip possesses a parallel micro-chamber design, which is applied to high throughput EVs’ immobilization and detection. Four distinct fluorescently labelled antibodies are introduced into the platform for multiplexed detection of different EV surface biomarkers including ubiquitous EV biomarkers (i.e., tetraspanins; CD81) and putative HGSOC tumor biomarkers (i.e. EpCAM, CD24, EGFR). The phenotypic profiling of EVs is achieved by counting of fluorescent vesicles at a single particle level, which provides evidence for discriminating HGSOC patients from healthy controls. In addition, the developed approach surpassed conventional ELISA method in sensitivity, which has potential in early clinical diagnosis of HGSOC for improved personal treatment.

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