Advanced microfluidic technologies for isolating extracellular vesicles

Extracellular vesicles (EVs) are lipid membrane-enclosed, cell-secreted nanovesicles that have attracted significant attentions in recent years in view of their potential as non-invasive cancer diagnostic biomarkers. However, isolation and analysis of EVs from biofluids remain a challenging field due to their small size, heterogeneous marker expression, and co-existence with non-vesicular contaminants. Microfluidic techniques provide a promising approach for isolating and analyzing EVs with advantages of small sample consumption, precise fluid control, high resolution and yield, short processing time, and cost effectiveness. In this review, we summarize recent efforts in developing label-free and affinity-based microfluidic methods for isolation of EVs according to their physical and biological characteristics, and their applications in cancer diagnostics. We conclude this review with key challenges and directions for microfluidic methods for EV isolation and analysis in clinical settings. • Extracellular vesicles have great potential as cancer diagnostic biomarkers. • Advanced microfluidic systems for isolation and analysis of EVs are reviewed. • Effective detection of EVs for cancer diagnostics is discussed. • Challenges for the utility of EVs in cancer diagnostics are presented.