Microfluidic methods used in exosome isolation

Exosomes are important biomarkers for clinical diagnosis. It is critical to isolate secreted exosomes from bodily fluids such as blood, saliva, breast milk, and urine for liquid biopsy applications. The field of microfluidics provides numerous benefits for biosample processing, diagnostics, and prognostics. Several microfluidics-based methods have been employed for the isolation and purification of exosomes in the last ten years. These microfluidic methods can be grouped into two categories based on passive and active isolation mechanisms. In the first group, inertial and hydrodynamic forces are employed to separate exosomes based on their size differences. In the second group, external forcefields are integrated into microfluidic platforms to actively isolate exosomes from other bioparticles. In this paper, the application of microfluidic methods in exosome isolation is discussed, and future perspectives on this field are highlighted.