Extracellular vesicle isolation: present and future
In recent years, extracellular vesicle (EV)-based biomarker discovery has received significant interest amongst scientist studying diverse disease conditions. Extracellular vesicles are released by variety of cells into the cellular microenvironment and have the natural ability of delivering different cargos and carry bioactive molecules such as non-codding RNA, genomic DNA, lipids, growth factors, and signaling molecules. EVs have been isolated from most biofluids including serum, plasma, serum, and saliva. It has been shown that EVs play substantial roles not only in the regulation of normal physiological processes but also in disease pathogenesis and their cargo reflects the status of parental cells at the time of secretion (1,2). Multiple studies found EVs enriched in lipid raft molecules (Flotillin) (3), membrane trafficking molecules (Annexins) and heat-shock proteins (HSP70, HSP90) (3,4). Based on mode of biogenesis, EVs can be divided into exosomes (30−100 nm), microvesicles (100−1,000 nm) and apoptotic bodies (>1,000 nm). The biogenesis and cellular pathways for generation of these different vesicle types, as well as their cargo, membrane composition and surface molecules are distinct with some overlapping features (5,6).