A high-throughput magneto-electrochemical array for the integrated isolation and profiling of extracellular vesicles from plasma

The analysis of proteins expressed on circulating extracellular vesicles (EVs) could facilitate the diagnosis of different types of cancers. EV assays however have lengthy sample workups and limited throughput and sensitivity, making them unsuitable for routine clinical use. Here, we report a high-throughput assay that integrates EV enrichment, via antibody-coated magnetic beads, with the detection of EV-bound antibodies, via an electrochemical reaction. The assay requires less than one hour, is performed on plasma samples, and its 96-well plate format enables measurements in parallel via a prototype reader. Using samples from patients with colorectal cancer or healthy volunteers, we identified a panel of biomarkers (EGFR, EpCAM, CD24, GPA33) in circulating EVs that, when combined, showed higher diagnostic accuracy (>96%) than conventional assays. In a prospective cohort, the combined biomarker profile enabled assigning patients to a high- or a low-risk 5-year disease-free survival group, and the serial monitoring of EVs during therapy showed values declined after surgery yet increased upon relapse. Biomarker panels from plasma EVs may be suitable for the non-invasive monitoring of disease trajectory.