Microfluidic Lab-on-a-Chip Based on UHF-Dielectrophoresis for Stemness Phenotype Characterization and Discrimination among Glioblastoma Cells

Abstract

Glioblastoma (GBM) is one of the most aggressive solid tumors, particularly due to the presence of cancer stem cells (CSCs). Nowadays, the characterization of this cell type with an efficient, fast and low-cost method remains an issue. Hence, we have developed a microfluidic lab-on-a-chip based on dielectrophoresis (DEP) single cell electro-manipulation to measure the two crossover frequencies: fx01 in the low-frequency range (below 500 kHz) and fx02 in the ultra-high-frequency range (UHF, above 50 MHz). First, in vitro conditions were investigated. An U87-MG cell line was cultured in different conditions in order to induce an undifferentiated phenotype. Then, ex vivo GBM cells from patients’ primary cell culture were passed through the developed microfluidic system and characterized in order to reflect clinical conditions. This article demonstrates that the usual exploitation of low-frequency range DEP does not allow the discrimination of the undifferentiated GBM cells from the differentiated one. However, the presented study highlights the use of UHF-DEP as a relevant discriminant parameter. The proposed microfluidic lab-on-a-chip is able to follow the kinetics of U87-MG phenotype transformation in a CSC enrichment medium and the cancer stem cells phenotype acquirement.

Subdividing Stress Groups into Eustress and Distress Groups Using Laterality Index Calculated from Brain Hemodynamic Response

“…Functional near-infrared spectroscopy (fNIRS) is a state-of-the-art optical neuroimaging technique based on near-infrared biosensors that are used to identify stress levels. Physically, fNIRS has the advantage of being more accessible and convenient than other devices [ 9 , 10 , 11 , 12 ]. Additionally, brain hemodynamic responses acquired by fNIRS not only exhibit apparent differences between stressful tasks and rest states but also facilitate stress detection and diagnosis [ 13 , 14 , 15 ].…”

The Role of Dielectrophoresis for Cancer Diagnosis and Prognosis

“…When the frequency becomes higher, the electric field starts penetrating inside the cell, thus “probing” its content. For this reason, can be used to discriminate cells based on cytoplasm features [ 25 ], though, because of the technical difficulties associated with the high-frequency actuation and the high sensitivity of the DEP response to small cell variations within cell subpopulations, the separation of cells based on , generally referred to as ultra-high-frequency, UHF, DEP, has not been extensively explored as compared with low-frequency, -based, DEP.…”

“…DEP can be applied for the detection of many sub-types of stem cells, including mesenchymal cells, neural stem cells, one marrow-derived mesenchymal stem cell, neural stem/progenitor cells and adipose tissue-derived stem cells [ 37 ]. However, for the sorting of CSCs, current DEP applications have been focused on glioblastoma stem cells (GBSCs) [ 25 , 38 ]. Interestingly, Lambert et al suggested that the expression of biological GBSCs markers and the measurement of the ultra-high-frequency crossover frequency f x 02 were closely linked [ 25 ].…”

“…However, for the sorting of CSCs, current DEP applications have been focused on glioblastoma stem cells (GBSCs) [ 25 , 38 ]. Interestingly, Lambert et al suggested that the expression of biological GBSCs markers and the measurement of the ultra-high-frequency crossover frequency f x 02 were closely linked [ 25 ]. …”

Effects of Ultra-Short Pulsed Electric Field Exposure on Glioblastoma Cells

“…The lower permeabilization induced in U87 NS by the electric field could also depend on their specific intracellular dielectric characteristics. Indeed, the more differentiated tumor cells (U87 ML) can be identified and separated from the more undifferentiated stem subpopulation (U87 NS) on the basis of specific cytoplasmic redox characteristics [ 47 , 48 ] related to transmembrane proteins [ 47 , 48 , 49 ].…”