Affinity-Based Enrichment of Extracellular Vesicles with Lipid Nanoprobes

Abstract

Extracellular vesicles (EVs) are lipid-bilayer-enclosed vesicles with sub-micrometer size that are released by various cells. EVs contain a tissue-specific signature wherein a variety of proteins and nucleic acids are selectively packaged. Growing evidence has shown important biological roles and clinical relevance of EVs in diseases. For EV-related studies to thrive, rapid efficient isolation of pure EVs is a prerequisite. However, lengthy procedure, low yield, low throughput, and high contaminants stemmed from existing isolation approaches hamper both basic research and large-scale clinical implementation. We have shown that lipid nanoprobes (LNP) enable spontaneous labeling and rapid isolation of EVs by coupling with magnetic enrichment. Recently, we further developed a one-step EV isolation platform that utilizes EV size-matched silica nanostructures and surface-conjugated LNPs with an integrated microfluidic mixer. EVs, derived from up to 2-ml clinical plasma, can be processed with this point-of-care device using optimized flow rate. Subsequently, contents of isolated EVs can be extracted on-chip and eluted from the device for downstream molecular analyses. The LNP-functionalized microfluidic device combined with state-of-the-art analysis platforms could have great potential in promoting EV-centered research and clinical use in the future.

Keywords: Extracellular vesicles; Lipid nanoprobe; Liquid biopsy; Microfluidic device; Nanostructured substrate.