Extracellular vesicles: A comprehensive review of classification, isolation, characterization, and cargo loading

Abstract

Extracellular vesicles (EVs) are submicron membrane-bound structures released from various cell types into extracellular space. EVs are divided by biogenesis into exosomes, microvesicles and apoptotic bodies; moreover, they can also be subtyped into natural, engineered and hybrid EVs. EVs play a vital role in cell-to-cell communication, allowing cells to exchange cargos including proteins, lipids and nucleic acid materials, therefore making them valuable tools as novel biomarkers of diseases, as therapeutic agents and as drug delivery messengers. In this review, we describe several methods for isolation and characterization of EVs. Furthermore, engineered EVs as target drug delivery systems as well as recent advances in hybrid EVs and the engineering of EVs with synthetic lipid nanoparticles will also be discussed.