Exosome-Based Non-Traditional Technologies Towards Multi-Parametric and Integrated Approaches for SARS-CoV-2

Background: This study proposed to repurpose extracellular vesicle (EV) separation and characterization technologies into a fully automated SARS-CoV-2 testing platform that was low-cost, accurate, sensitive, rapid (within 3 hours), and practical. Materials/Methods: The device was optimized to analyze blood, saliva, and nasopharyngeal swabs collected at home, without risking transmission to healthcare workers. The sample was processed with an automated device developed with Sognef, and data were transferred to the Sognef servers for analysis through an app that could be downloaded to any smart device. This technology had the advantage of multiparametric detection of viral RNA (vRNA), including Spike (S) and Nucleocapsid (N) protein-coding regions, plus a panel of host EV microRNAs (exomiRs) that revealed infection even when viral loads were below detectable limits. Outcome/Impact: This study optimized a COVID-19 device that used simple bind-elute microfluidics for sample separation followed by electrical, probe-based detection of validated exomiRs and conserved vRNAs. To reduce false positives, the device was envisioned to be used first for either finger-pricked blood or saliva, and if positive, followed by an optional confirmatory second test of nasopharyngeal swab viral transport medium (VTM) that could be done with the same device.