Review: Isolation and Detection of Tumor-Derived Extracellular Vesicles

Exosomes play a significant role in cancer progression and are potentially useful biomarkers for noninvasive diagnostics and therapeutic treatments. Although exosomes are difficult to study because of their small, inconsistent sizes and challenging purification processes, new micro- and nanotechnologies have been recently developed that seek to overcome these limitations. In this review, we examine and compare isolation and detection techniques for various types of extracellular vesicles (EVs) including exosomes, which have sizes <200 nm and microvesicles (MVs), which are >200 nm. Various microfluidic devices that offer better EV purity, higher recovery rates, lower costs, decreased isolation times, and low sample volumes compared to conventional techniques are described with an emphasis on the importance of micro- and nanobased technologies to isolate and detect EVs for the point-of-care acquisition and diagnosis of cancer.