Submicron Particle Focusing and Exosome Sorting by Wavy Microchannel Structures within Viscoelastic Fluids

Area of Science:

• Biotechnology
• Nanotechnology
• Biomedical Engineering

Background:

• Exosomes are vital biomarkers for liquid biopsy, but their small size complicates isolation from bodily fluids.
• Current isolation methods face challenges in achieving high throughput and purity.

Purpose of the Study:

• To develop a high-throughput, high-purity, and label-free method for isolating exosomes.
• To utilize elasto-inertial focusing in a microfluidic device for exosome separation.

Main Methods:

• A microfluidic device with a reverse wavy channel structure was designed.
• Viscoelastic fluids with biocompatible polymers were used to achieve elasto-inertial focusing.
• Separation efficiency was tested using fluorescently labeled submicron spheres of varying sizes.

Main Results:

• The device achieved label-free sorting of exosomes with >92% purity.
• Exosome recovery rates exceeded 81%.
• The wavy channel design enhanced particle focusing compared to straight channels.

Conclusions:

• The developed elasto-inertial exosome sorting technique offers a promising platform for biological research.
• This method addresses the challenges of isolating small nanoparticles like exosomes.
• Potential applications include diagnostics and pharmaceutical development.