Acoustic Enrichment of Extracellular Vesicles from Biological Fluids

Abstract

Extracellular vesicles (EVs) have emerged as a rich source of biomarkers providing diagnostic and prognostic information in diseases such as cancer. Large-scale investigations into the contents of EVs in clinical cohorts are warranted, but a major obstacle is the lack of a rapid, reproducible, efficient, and low-cost methodology to enrich EVs. Here, we demonstrate the applicability of an automated acoustic-based technique to enrich EVs, termed acoustic trapping. Using this technology, we have successfully enriched EVs from cell culture conditioned media and urine and blood plasma from healthy volunteers. The acoustically trapped samples contained EVs ranging from exosomes to microvesicles in size and contained detectable levels of intravesicular microRNAs. Importantly, this method showed high reproducibility and yielded sufficient quantities of vesicles for downstream analysis. The enrichment could be obtained from a sample volume of 300 μL or less, an equivalent to 30 min of enrichment time, depending on the sensitivity of downstream analysis. Taken together, acoustic trapping provides a rapid, automated, low-volume compatible, and robust method to enrich EVs from biofluids. Thus, it may serve as a novel tool for EV enrichment from large number of samples in a clinical setting with minimum sample preparation.

Extracellular vesicle identification in tooth movement models

“…Various approaches have been tested for isolating EVs. A recent article described the use of creating a standing wave in a microfluidic chamber (Figure ). Polystyrene beads are used as seeding particles, which are retained in the standing wave.…”

“…Various approaches have been tested for isolating EVs. A recent article described the use of creating a standing wave in a microfluidic chamber 30 (Figure 2 F I G U R E 1 Detection of EVs using the ExoView platform (NanoView Biosciences) utilizing specific labelling of EVs, bound to the surface with CD63 antibody, and detected with fluorescently tagged anti-CD63 antibody. A, Schematic of NanoView Biosciences detection system.…”

MicroRNAs from Liquid Biopsy Derived Extracellular Vesicles: Recent Advances in Detection and Characterization Methods

“…Still, the same miRNAs could be found in comparable concentrations of EVs in urine and serum samples in a comparison of both isolation methods. This suggests that the amount of EVs isolated by acoustic trapping might be sufficient for diagnostic purposes [135]. Another study revealed that the RNA yield of EVs from an equivalent of 1.7 mL urine is sufficient to generate a NEXTflex cDNA library for Illumina Next Generation Sequencing (NGS) of miRNAs.…”

“…Another study revealed that the RNA yield of EVs from an equivalent of 1.7 mL urine is sufficient to generate a NEXTflex cDNA library for Illumina Next Generation Sequencing (NGS) of miRNAs. Hence, this method represents a fast, automated alternative to ultracentrifugation [109,135]. The method was further improved by combining an acoustic trap and a microfluidic chip.…”

The Effect of Proteome and Lipidome on the Behavior of Membrane Bound Systems in Thermally-Assisted Acoustophoresis

“…125,147 More recently, enrichment of EVs from biological fluids was achieved using tilted-angle standing sequential surface acoustic wave (taSSAW) 181 and beadmediated acoustic trapping. [182][183][184] As was mentioned in Section 1.3, separation in acoustophoresis is mainly realized through the size-and/or density-based differences in the primary acoustic radiation force exerted on the particles, described by Equation (1 We previously demonstrated that lipid vesicles can undergo a reversible nodal or anti-nodal migration in a thermally-modulated ultrasonically-stimulated microfluidic channel. 185 The switch from nodal to anti-nodal focusing was determined to occur at a specific transition temperature attributed to a biomechanical transition in the stiffness of vesicles as the lipid membrane undergoes a thermotropic transition from an ordered "gel" phase to a disordered "fluid" phase.…”