Extracellular Vesicles Isolation from Large Volume Samples Using a Polydimethylsiloxane-Free Microfluidic Device

Abstract

Extracellular vesicles (EV) have many attributes important for biomedicine; however, current EV isolation methods require long multi-step protocols that generally involve bulky equipment that cannot be easily translated to clinics. Our aim was to design a new cyclic olefin copolymer–off-stoichiometry thiol-ene (COC–OSTE) asymmetric flow field fractionation microfluidic device that could isolate EV from high-volume samples in a simple and efficient manner. We tested the device with large volumes of urine and conditioned cell media samples, and compared it with the two most commonly used EV isolation methods. Our device was able to separate particles by size and buoyancy, and the attained size distribution was significantly smaller than other methods. This would allow for targeting EV size fractions of interest in the future. However, the results were sample dependent, with some samples showing significant improvement over the current EV separation methods. We present a novel design for a COC–OSTE microfluidic device, based on bifurcating asymmetric flow field-flow fractionation (A4F) technology, which is able to isolate EV from large volume samples in a simple, continuous-flow manner. Its potential to be mass-manufactured increases the chances of implementing EV isolation in a clinical or industry-friendly setting, which requires high repeatability and throughput.

Exploring the role of polymers to overcome ongoing challenges in the field of extracellular vesicles

“…Alternatively, PDMS‐free microfluidic devices were investigated based on cyclic olefin copolymers (COC) using off‐stoichiometry thiol‐ene chemistry (OSTE). Thermoplastics can also be used as they are more prone to mass‐production and easy to modify regarding surface chemistry (Bajo‐Santos et al., 2023 ; Jackson et al., 2014 ; O'Neil et al., 2016 ; ONeil et al., 2016 ). Thus, microchips made of COC were manufactured by micro‐injection moulding to create herringbone structure.…”