Microfluidic devices for on-chip quantification of extracellular vesicles and associated biomarkers.

In the past decade, extracellular vesicles (EVs) have gained increasing attention in biomedical research. These membrane-bound particles are naturally secreted by cells under both physiological and pathological conditions, and they exhibit a wide range of sizes and molecular compositions. EVs transport bioactive molecules - such as proteins, nucleic acids, and lipids - making them ideal candidates for biomarker discovery. Consequently, their accurate characterization and quantification are critical for understanding their roles in intercellular communication and evaluating their potential in diagnostics, prognostics, disease monitoring, and therapeutic applications. Microfluidic technologies offer promising solutions for EV analysis, addressing key limitations of conventional methods by enabling precise and sensitive measurements with small sample volumes. While microfluidic devices have been predominantly used for EV separation and isolation, their application in EV quantification remains underexplored. Compared to traditional techniques like nanoparticle tracking analysis or flow cytometry, microfluidic systems can provide faster, more accessible alternatives for EV quantification. This review summarizes recent advances in microfluidic technologies for EV quantification, discussing their advantages, current limitations, and future prospects.