NanoBioAnalytical tools for blood derived extracellular vesicles characterization

International audienceExtracellular Vesicles (EVs) represent a group of heterogeneous populations of vesicles that are found in essentially all body fluids, and circulate under physiological conditions in blood at concentrations of &gt109/mL. However, circulating EVs numbers were found to increase under several pathological situations. Those cell-derived EVs are composed of exosomes, ectosomes and apoptotic bodies, they originate from different cells and processes, and range from approximately 30 nm to 1 μm in diameter. Analyzing these EVs in their entirety while discriminating them in subsets remains a huge scientific challenge. There is a consensus that combining physical, optical, functional, and proteomic methods provides the best characterization of extracellular vesicles present in blood components. This is needed to tackle EVs heterogeneity in size, function, refractive index, cellular origin, and content and to counterbalance interference from protein aggregates or complexes, microprecipitates, as well as blood-borne lipoproteins.Our approach consists in proposing a Nano-Bio-Analytical platform (NBA) combining Surface Plasmon Resonance imaging (SPRi), Mass Spectrometry and Atomic Force Microscopy (AFM) enabling EVs phenotyping, proteomic profiling and nanometrology. This NBA platform already gave a new introspection of platelet-derived EVs samples, showing that more than 95% of the vesicles were below 300 nm in diameter, over a wide concentration range (107 to 1012 vesicles/ml) (Obeid S. et al, Biosens. Bioelec 2017). Latest developments around the NBA will be presented during the symposium