Methods for Extracellular Vesicle Isolation: Relevance for Encapsulated miRNAs in Disease Diagnosis and Treatment

Extracellular Vesicles (EVs) are nanovesicles that facilitate intercellular communication by carrying essential biomolecules under physiological and pathological conditions including microRNAs (miRNAs). They are found in various body fluids, such as blood, urine, and saliva, and their levels fluctuate with disease progression, making them valuable diagnostic tools. However, isolating EVs is challenging due to their small size and biological complexity. Here we summarize principles behind most common EV isolation methods including ultracentrifugation, precipitation, immunoaffinity, flow cytometry, ultrafiltration, size-exclusion chromatography, and microfluidics while highlighting protocol strengths and weaknesses. We also review main strategies to identify and quantify circulating miRNAs with a particular focus on EV- encapsulated miRNAs. Since these miRNAs hold special clinical interest derived from their superior stability and therapeutic potential, the information provided here should provide valuable guidance for future research initiatives in the promising field of disease diagnostic and treatment based on EV-encapsulated miRNAs.