A modular microfluidic platform for serial enrichment and harvest of pure extracellular vesicles

Extracellular vesicles (EVs) are recognized as promising biomarkers for several diseases. However, their conventional isolation methods have several drawbacks, such as poor yields, low purity, and time-consuming operations. Therefore, a simple, low-cost, and rapid microfluidic platform has been extensively developed to meet the requirement in biomedical applications. Herein, a modular microfluidic platform is demonstrated to isolate and enrich EVs directly from plasma, in a combination of continuous capture and purification of EVs. The EVs were selectively captured by target-specific antibody-coated beads in a horseshoe-shaped orifice micromixer (HOMM) chip within 2 min. A fish-trap-shaped microfilter unit was subsequently used to elute and purify the affinity-induced captured EVs from the microbeads. The ability of the modular chip to capture, enrich, and release EVs was demonstrated in 5 min (100 mu L sample) at high throughput (100 mu L min(-1)). The two chips can be modularized or individually operated, depending on the clinical applications such as diagnostics and therapeutics. For the diagnostic applications, the EVs on microbeads can be directly subjected to the molecular analysis whereas the pure EVs should be released from the microbeads for the therapeutic treatments. This study reveals that the fabricated modular chip can be appropriately employed as a platform for EV-related research tools.

Automated summary

This study demonstrates the development of a modular microfluidic platform for the direct isolation and enrichment of EVs from plasma, achieving efficient capture, enrichment, and release of EVs. The use of target-specific antibody-coated beads and a fish-trap-shaped microfilter unit enables rapid and efficient purification of pure EVs.