Abstract

Acoustic Trapping Mediated High-Throughput (0.5 ml/min) Isolation of Extracellular Vesicles

Thomas Laurell, Professor, Lund University

Rapid and clinical scale isolation of extracellular vesicles (EV) from biofluids remains a major bottle neck in EV biomarker screening studies. Microfluidics has over the past years demonstrated several potential principles for EV isolation, however commonly suffering from limited capacity and/or sample throughput. In this perspective, acoustic nanoparticle trapping has emerged as an option for EV enrichment from biofluids where acoustic sound scattering, between microbeads and extra cellular vesicles, enrich EVs onto microbeads in a stationary cluster that is retained by the local acoustic field gradient. The technique has been used in investigations of EVs in blood plasma and urine. Traditionally this has been performed at a sample flow rate of ˜ 20 uL/min in a half wavelength acoustic standing wave trap, localized in a glass capillary, which when processing larger samples volumes, for increased biomarker sensitivity or when enriching EVs from dilute biofluids such as urine, suffer from extended processing times. To overcome this limitation we have developed an acoustic trapping unit, with ten standing wave nodes, that offers up to 40X increased trapping capacity and 25-40X increased sample processing flow rate. A typical sample flow rate of 500 uL/min enables rapid EV isolation and washing of milliliter volumes of urine as well as blood plasma in minutes prior to MS proteomic analysis. The proteome analysis of the acoustically enriched EV fraction displays clustering of proteins at elevated levels as compared to the input sample, suggesting a sub proteome specifically linked to the EVs. Furthermore, studies on EVs derived from pathogen activated platelets will be presented.