Label-free detection of hypoxia-induced extracellular vesicle secretion from MCF-7 cells

Abstract

Nanoscale extracellular vesicles (EVs) including exosomes (50–150 nm membrane particles) have emerged as promising cancer biomarkers due to the carried genetic information about the parental cells. However the sensitive detection of these vesicles remains a challenge. Here we present a label-free electrochemical sensor to measure the EVs secretion levels of hypoxic and normoxic MCF-7 cells. The sensor design includes two consecutive steps; i) Au electrode surface functionalization for anti-CD81 Antibody and ii) EVs capture. The label-free detection of EVs was done via Differential Pulse Voltammetry (DPV) and Electrochemical Impedance Spectroscopy (EIS). The working linear range for the sensor was 102–109 EVs/ml with an LOD 77 EVs/mL and 379 EVs/ml for EIS and DPV based detection. A blood-abundant protein, RhD was used for the selectivity test. In order to assess the performance of the biosensor, the level of EVs secretion by the human breast cancer MCF-7 cell line was compared with enzyme-linked immunosorbent assays (ELISA) and Nanoparticle Tracking Analysis (NTA). Designed label-free electrochemical sensors utilized for quantification of EVs secretion enhancement due to CoCl2-induced hypoxia and 1.23 fold increase with respect to normoxic conditions was found.

Tuberous Sclerosis Complex Axis Controls Renal Extracellular Vesicle Production and Protein Content

“…Adding to this stimulation, the increase in mTORC1 activity drives hypoxia inducible factor synthesis and release [38,39]. This hypoxia signaling also is a strong inducer of EV production [31,40].…”

Electrochemical Impedance Spectroscopy Based Biosensors: Mechanistic Principles, Analytical Examples and Challenges towards Commercialization for Assays of Protein Cancer Biomarkers

“…A novel and potentially promising area emerged recently – assay of exosomes and microvesicules . Nanoscale extracellular vesicles (EVs) including exosomes (membrane particles with size 50–150 nm) appeared as promising cancer biomarkers since they carry genetic information about the parental cells.…”

“…Nanoscale extracellular vesicles (EVs) including exosomes (membrane particles with size 50–150 nm) appeared as promising cancer biomarkers since they carry genetic information about the parental cells. Label‐free EIS sensor measuring EVs secretion levels from hypoxic and normoxic MCF‐7 cells (a breast cancer cell line) exhibited linear range from 10 2 to 10 9 EVs mL −1 with LOD of 77 EVs mL −1 …”

Isolation, characterisation and detection of breath-derived extracellular vesicles

“…EVs from EBC are, therefore, a feasible target to analyse when compared to small molecules (such as volatile organic compounds), as they are a larger size of 40-100 nm (making them easier to detect, capture and characterise), highly abundant and have accessible and specific target proteins on the surface. The detection of EVs using plasmonic and electrochemical sensors has been done previously using specific cell-line derived EVs 12,13 . Kilic et al 13 showed the use of an electrochemical sensor to measure EVs isolated from a MCF-7 cell line.…”

“…The detection of EVs using plasmonic and electrochemical sensors has been done previously using specific cell-line derived EVs 12,13 . Kilic et al 13 showed the use of an electrochemical sensor to measure EVs isolated from a MCF-7 cell line. However, this is the first attempt at detecting of EVs isolated from EBC with low available concentrations.…”