Methods in Extracellular Vesicle Isolation, Characterization, and Production

Extracellular vesicles (EVs) are nanoscale membrane-derived particles that play crucial roles in intercellular communication. To better understand the biological functions and evaluate their potential as diagnostic and therapeutic biomarkers, appropriate isolation and characterization of EVs are fundamental steps. EVs can be isolated from complex biological samples using various techniques such as ultracentrifugation, size-exclusion chromatography, immunoaffinity capture techniques, etc. Each method has its own advantages and limitations, such as scalability, purity, and yield. The gold standard technique, ultracentrifugation, involves sequential centrifugation steps to pellet EVs based on size and density. EVs are characterized by evaluating their physical, biochemical, and functional properties. Multiple techniques are integrated for comprehensive EV analysis and quality control. Transmission and scanning electron microscopy techniques enable the visualization and morphological analysis of EVs. Nanoparticle tracking analysis and dynamic light scattering provide insights into the size distribution and concentration of EVs. Molecular characterization techniques facilitate the identification and quantification of EV cargo. In addition to isolating and characterizing naturally occurring EVs, researchers have developed methods for the production of engineered EVs with modified cargo, offering potential applications in drug delivery and therapeutics. Increased production of naturally occurring EVs can be achieved by genetic engineering or chemical stimulation. Alternatively, EVs can be manufactured artificially using nitrogen cavitation, sonication, extrusion through polycarbonate membranes or microfluidic devices, etc. Optimization of the production process is necessary to obtain EVs with desired characteristics, such as size, surface markers, and cargo composition. This chapter offers a concise summary of the methods used for EV production, isolation, and characterization.