Abstract
One of the challenges of exploiting extracellular vesicles (EVs) as a disease biomarker is to differentiate EVs released by similar cell types or phenotypes. This paper reports a high-throughput and label-free EV microarray technology to differentiate EVs by simultaneous characterization of a panel of EV membrane proteins. The EsupplV microarray platform, which consists of an array of antibodies printed on a photonic crystal biosensor and a microscopic hyperspectral imaging technique, can rapidly assess the binding of the EV membrane proteins with their corresponding antibodies. The EV microarray assay requires only a 2 μL sample volume and a detection time of less than 2 h. The EV microarray assay was validated by not only quantifying seven membrane proteins carried by macrophage-derived EVs but also distinguishing the EVs secreted by three macrophage phenotypes. In particular, the EV microarray technology can generate a molecular fingerprint of target EVs that can be used to identify the EVs' parental cells, and thus has utility for basic science research as well as for point-of-care disease diagnostics and therapeutics.