Micro- and Nanopillar Chips for Continuous Separation of Extracellular Vesicles

Area of Science:

• Biomolecular Engineering
• Nanotechnology
• Analytical Chemistry

Background:

• Micro- and nanopillar chips are established tools for biomolecule separation and analysis.
• Extracellular vesicles (EVs) are crucial biomarkers found in biofluids, typically ranging from 50-200 nm.
• Accurate separation and enrichment of EVs are vital for research and clinical diagnostics.

Purpose of the Study:

• To develop a continuous, precise, and accurate separation technique for extracellular vesicles (EVs).
• To leverage electroosmotic flow-driven deterministic lateral displacement for nanoparticle separation.
• To demonstrate the utility of micro- and nanopillar chips for EV isolation.

Main Methods:

• Utilized micro- and nanopillar array chips for separation.
• Employed electroosmotic flow (EOF) for deterministic lateral displacement.
• Applied electric fields to reservoirs containing electrodes for flow control.
• Observed nanoparticle flow behavior within the pillar arrays.

Main Results:

• Achieved continuous, accurate, and precise separation of nanoparticles (50-500 nm), including EVs.
• Demonstrated that EOF velocity in nanopillar arrays exhibits a parabolic flow profile.
• Showed that EOF velocity is not solely dependent on surface counterion mobility.

Conclusions:

• The developed technique offers a hydrodynamic pressure-free, easy-to-use method for EV separation and enrichment.
• This approach enables precise analysis of EV size and composition.
• The technique holds promise for future research and clinical diagnostic applications of EVs.