Comparison of Extracellular Vesicle Characterization Methods
Extracellular vesicles(EVs)are vesicles with phospholipid bilayer structure actively secreted by cells,which naturally carry various contents derived from mother cells.EVs retain the biological char-acteristics of mother cells and reflect the status of mother cells during their secretion.In order to under-stand the biogenesis of EVs and their biological functions in the body,scientists have made many at-tempts.However,direct detection of EVs has some difficulties and current detection techniques usually use EVs contents as detection objects to achieve the purpose of indirect characterization.The purpose of disease diagnosis can be achieved by analyzing EVs in body fluids,and detailed characterization of EVs can promote the development of precision medicine.EVs belong to endogenous substances and can be used as carriers to deliver drugs,with the advantages of increasing efficacy,reducing drug toxicological effects and passing through biological barriers.When EVs applied as a drug or a carrier for delivering drug,challenges to be addressed include(ⅰ)clear characterization of the contents of EVs,(ⅱ)develop-ment of suitable assays to monitor EVs in vivo to determine and optimize the dose,route of administra-tion,and potential toxicity of EVs,and (ⅲ) determination of the kind and amount of membrane compo-sition of EVs.The diameter of EVs is nanoscale and the content is small,but it is of great value in clini-cal application.The selection of appropriate analytical techniques in the application will enable a compre-hensive characterization of EVs and further advance our understanding of EVs biology to develop novel di-agnostic and therapeutic approaches.In this review,the principles,applications,advantages and disad-vantages of analytical techniques in the study of EVs are introduced,with emphasis on the characteriza-tion techniques of EVs.