Magnetic particle based liquid biopsy chip for isolation of extracellular vesicles and characterization by gene amplification

Extracellular vesicles (EVs) are the cell-derived vesicles which play a critical role in cell-to-cell communication, and disease progression. These vesicles contain a myriad of substances like RNA, DNA, proteins, and lipids from their origin cells, offering a good source of biomarkers. The existing methods for the isolation of EVs are time-consuming, lack yield and purity, and expensive. In this work, we present a magnetic particle based liquid biopsy chip for the isolation of EVs by using a synthetic peptide, Vn96. To ensure capture efficiency, a 3D mixer is integrated in the chip, along with a sedimentation unit, which allows EV-captured magnetic particles to settle in it based on gravity assisted sedimentation. The captured EVs are then isolated for their elution and validation. The EVs are characterized by the scanning electron microscopy (SEM) measurements and the ability of capture and isolation of EVs is validated by the nanoparticle tracking analysis (NTA) and atomic force microscopy (AFM). The DNA content of the EVs is further characterized by the absolute quantification of a housekeeping gene (RNase P) copies using droplet digital PCR (ddPCR). The results show that the chip can capture and isolate the EVs, without affecting their morphology. Thus, the liquid biopsy chip can be considered as a potential point of care device for diagnostics in a clinical setting. •Isolation of Extracellular vesicles (EVs) from MCF7 CCM by the streptavidin coated magnetic particles.•Immunoaffinity isolation by synthetic peptide Vn96 by binding to the heat shock proteins present on the surface of EVs.•Magnetic particle based liquid biopsy chip for easy capture of EVs from the CCM and simple isolation using a magnet.•Liquid biopsy chip integrated with a split and recombine 3D mixer for mixing the Vn96 bound magnetic particles and MCF7 CCM to capture EVs and a sedimentation unit for them to settle.•The maximum isolation efficiency obtained was around 90% with 8.0–9.9 μm magnetic particles in case of 0.2 ml MCF7 CCM used.