New Method Promises Rapid Isolation of Biomarker-Rich Extracellular Vesicles

A new method for isolating and analyzing cancer biomarkers from extracellular vesicles present in biological fluids is based on a novel magnetic particle based liquid biopsy chip.

Extracellular vesicles (EVs) are 40 to 200 micron cell-derived vesicles which play a critical role in cell-to-cell communication, and disease progression. These vesicles, which are present in all biological fluids, contain a wide variety of molecular species such as RNA, DNA, proteins, and lipids from their origin cells, offering a good source of biomarkers. However, existing methods for the isolation of EVs are time-consuming, lack yield and purity, and are expensive.

An improved procedure for isolation and recovery of EVs was recently described by investigators at Concordia University (Montreal, Canada). The new method employed a magnetic particle based liquid biopsy chip for the isolation of EVs by incorporating a synthetic peptide, Vn96. This magnetically labeled peptide enabled immunoaffinity isolation of the EVs by binding to the heat shock proteins present on their surface.

A split and recombine three-dimensional randomizer for mixing the Vn96 bound magnetic particles was an integral component of the liquid biopsy chip. Furthermore, a built-in sedimentation unit allowed the captured EVs to settle. The captured EVs were then isolated for elution and validation using proteomic and genomic techniques.

The results obtained during this study demonstrated that the chip could capture and isolate EVs, without affecting their morphology.

"This technique can provide a very early diagnosis of cancer that would help find therapeutic solutions and improve the lives of patients," said senior author Dr. Muthukumaran Packirisamy, professor of mechanical, industrial, and aerospace engineering at Concordia University. "Liquid biopsies avoid the trauma of invasive biopsies, which involve exploratory surgery. We can get all the cancer markers and cancer prognoses just by examining any bodily fluid."

Details of the liquid biopsy chip will be published in the December 15, 2021, issue of the journal Biosensors and Bioelectronics.

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