Assay based on electrical impedance spectroscopy to discriminate between normal and cancerous mammalian cells

The Diagnostic Accuracy of Electrical Impedance Spectroscopy-Assisted Colposcopy, HPV mRNA Test, and P16/Ki67 Immunostaining as CIN2+ Predictors in Greek Population

OBJECTIVE

To evaluate the diagnostic accuracy of Electrical Impedance Spectroscopy (EIS)-assisted colposcopy in detecting CIN2+ Greek women towards standalone colposcopy, HPV mRNA testing, and p16/Ki67 immunostaining.

METHODS

We conducted a cross-sectional observational study at the Cervical Pathology Clinic of the 2nd Obstetrics-Gynecology University Department of Hippokration Hospital Thessaloniki involving 316 patients from January 2022 to August 2023. All participants provided liquid-based cervical samples for cytology, HPV mRNA testing, and p16/Ki67 immunostaining.

MAIN OUTCOME MEASURES

Subsequently, participants underwent both standalone colposcopy and EIS/ZedScan-assisted colposcopy, followed by cervical punch biopsies.

RESULTS

The incorporation of EIS significantly enhanced the sensitivity of colposcopy, increasing it from 54.17% to 100%, equivalent to that of HPV mRNA testing and p16/Ki67 immunostaining, while achieving a high specificity (95.45%). The specificities observed with EIS/ZedScan-assisted and standalone colposcopy were notably superior to those of HPV-related biomarkers (HPV mRNA test and p16/Ki67 immunostaining). When compared to standalone colposcopy, HPV mRNA testing, and p16/Ki67 immunostaining, EIS/ZedScan-assisted colposcopy demonstrated the most favorable combination of Positive and Negative Predictive Values, at 90.57% and 100%, respectively. The inclusion of EIS/ZedScan in colposcopy led to the detection of 44 additional cases of true CIN2+ (100% of the total CIN2+ confirmed histologically) that were missed by standalone colposcopy. This discovery suggests a 45.83% increase in the detection of CIN2+ cases.

CONCLUSIONS

The integration of EIS with colposcopy has demonstrated effectiveness in detecting cervical lesions, resulting in a significant detection increase of CIN2+ cases while offering optimal levels of sensitivity, specificity, and predictive values for CIN2+ detection.

Plasma-liquid interactions in the presence of organic matter-A perspective

As investigations in the biomedical applications of plasma advance, a demand for describing safe and efficacious delivery of plasma is emerging. It is quite clear that not all plasmas are "equal" for all applications. This Perspective discusses limitations of the existing parameters used to define plasma in context of the need for the "right plasma" at the "right dose" for each "disease system." The validity of results extrapolated from in vitro studies to preclinical and clinical applications is discussed. We make a case for studying the whole system as a single unit, in situ. Furthermore, we argue that while plasma-generated chemical species are the proposed key effectors in biological systems, the contribution of physical effectors (electric fields, surface charging, dielectric properties of target, changes in gap electric fields, etc.) must not be ignored.

Amyloid-β Oligomer-Induced Electrophysiological Mechanisms and Electrical Impedance Changes in Neurons

Amyloid plays a critical role in the pathogenesis of Alzheimer's disease (AD) and can aggregate to form oligomers and fibrils in the brain. There is increasing evidence that highly toxic amyloid-β oligomers (AβOs) lead to tau protein aggregation, hyperphosphorylation, neuroinflammation, neuronal loss, synaptic loss, and dysfunction. Although the effects of AβOs on neurons have been investigated using conventional biochemical experiments, there are no established criteria for electrical evaluation. To this end, we explored electrophysiological changes in mouse hippocampal neurons (HT22) following exposure to AβOs and/or naringenin (Nar, a flavonoid compound) using electrical impedance spectroscopy (EIS). AβO-induced HT22 showed a decreased impedance amplitude and increased phase angle, and the addition of Nar reversed these changes. The characteristic frequency was markedly increased with AβO exposure, which was also reversed by Nar. The AβOs decreased intranuclear and cytoplasmic resistance and increased nucleus resistance and extracellular capacitance. Overall, the innovative construction of the eight-element CPE-equivalent circuit model further reflects that the pseudo-capacitance of the cell membrane and cell nucleus was increased in the AβO-induced group. This study conclusively revealed that AβOs induce cytotoxic effects by disrupting the resistance characteristics of unit membranes. The results further support that EIS is an effective technique for evaluating AβO-induced neuronal damage and microscopic electrical distinctions in the sub-microscopic structure of reactive cells.

A review of electrochemical impedance as a tool for examining cell biology and subcellular mechanisms: merits, limits, and future prospects

Herein the development of cellular impedance biosensors, electrochemical impedance spectroscopy, and the general principles and terms associated with the cell-electrode interface is reviewed. This family of techniques provides quantitative and sensitive information into cell responses to stimuli in real-time with high temporal resolution. The applications of cell-based impedance biosensors as a readout in cell biology is illustrated with a diverse range of examples. The current state of the field, its limitations, the possible available solutions, and the potential benefits of developing biosensors are discussed.

Cervical Cancer Therapeutics: An In-depth Significance of Herbal and Chemical Approaches of Nanoparticles

Cervical cancer emerges as a prominent health issue, demanding attention on a global level for women's well-being, which frequently calls for more specialized and efficient treatment alternatives. Traditional therapies may have limited tumour targeting and adverse side effects. Recent breakthroughs have induced a transformative shift in the strategies employed against cervical cancer. biocompatible herbal nanoparticles and metallic particles made of gold, silver, and iron have become promising friends in the effort to fight against this serious disease and understand the possibility of these nanoparticles for targeted medication administration. this review article delves into the latest advancements in cervical cancer research. The safety and fabrication of these nanomaterials and their remarkable efficacy against cervical tumour spots are addressed. This review study, in short, provides an extensive introduction to the fascinating field of metallic and herbal nanoparticles in cervical cancer treatment. The information that has been examined points to a bright future in which women with cervical cancer may experience fewer side effects, more effective therapy, and an improved quality of life. This review holds promise and has the potential to fundamentally reshape the future of cervical cancer treatment by addressing urgent issues and unmet needs in the field.

Phenotypic Characterization of 2D and 3D Prostate Cancer Cell Systems Using Electrical Impedance Spectroscopy

Prostate cancer is the second leading cause of death in men. A challenge in treating prostate cancer is overcoming cell plasticity, which links cell phenotype changes and chemoresistance. In this work, a microfluidic device coupled with electrical impedance spectroscopy (EIS), an electrode-based cell characterization technique, was used to study the electrical characteristics of phenotype changes for (1) prostate cancer cell lines (PC3, DU145, and LNCaP cells), (2) cells grown in 2D monolayer and 3D suspension cell culture conditions, and (3) cells in the presence (or absence) of the anti-cancer drug nigericin. To validate observations of phenotypic change, we measured the gene expression of two epithelial markers, E-cadherin (CDH1) and Tight Junction Protein 1 (ZO-1). Our results showed that PC3, DU145, and LNCaP cells were discernible with EIS. Secondly, moderate phenotype changes based on differences in cell culture conditions were detected with EIS and supported by the gene expression of CDH1. Lastly, we showed that EIS can detect chemoresistant-related cell phenotypes with nigericin drug treatment. EIS is a promising label-free tool for detecting cell phenotype changes associated with chemoresistance. Further development will enable the detection and characterization of many other types of cancer cells.

Electrical Characterization and Analysis of Single Cells and Related Applications

Biological parameters extracted from electrical signals from various body parts have been used for many years to analyze the human body and its behavior. In addition, electrical signals from cancer cell lines, normal cells, and viruses, among others, have been widely used for the detection of various diseases. Single-cell parameters such as cell and cytoplasmic conductivity, relaxation frequency, and membrane capacitance are important. There are many techniques available to characterize biomaterials, such as nanotechnology, microstrip cavity resonance measurement, etc. This article reviews single-cell isolation and sorting techniques, such as the micropipette separation method, separation and sorting system (dual electrophoretic array system), DEPArray sorting system (dielectrophoretic array system), cell selector sorting system, and microfluidic and valve devices, and discusses their respective advantages and disadvantages. Furthermore, it summarizes common single-cell electrical manipulations, such as single-cell amperometry (SCA), electrical impedance sensing (EIS), impedance flow cytometry (IFC), cell-based electrical impedance (CEI), microelectromechanical systems (MEMS), and integrated microelectrode array (IMA). The article also enumerates the application and significance of single-cell electrochemical analysis from the perspectives of CTC liquid biopsy, recombinant adenovirus, tumor cells like lung cancer DTCs (LC-DTCs), and single-cell metabolomics analysis. The paper concludes with a discussion of the current limitations faced by single-cell analysis techniques along with future directions and potential application scenarios.

Concepts, electrode configuration, characterization, and data analytics of electric and electrochemical microfluidic platforms: a review

Microfluidic cytometry (MC) and electrical impedance spectroscopy (EIS) are two important techniques in biomedical engineering. Microfluidic cytometry has been utilized in various fields such as stem cell differentiation and cancer metastasis studies, and provides a simple, label-free, real-time method for characterizing and monitoring cellular fates. The impedance microdevice, including impedance flow cytometry (IFC) and electrical impedance spectroscopy (EIS), is integrated into MC systems. IFC measures the impedance of individual cells as they flow through a microfluidic device, while EIS measures impedance changes during binding events on electrode regions. There have been significant efforts to improve and optimize these devices for both basic research and clinical applications, based on the concepts, electrode configurations, and cell fates. This review outlines the theoretical concepts, electrode engineering, and data analytics of these devices, and highlights future directions for development.

Dielectrophoretic and Electrical Impedance Differentiation of Cancerous Cells Based on Biophysical Phenotype

Here, we reported a study on the detection and electrical characterization of both cancer cell line and primary tumor cells. Dielectrophoresis (DEP) and electrical impedance spectroscopy (EIS) were jointly employed to enable the rapid and label-free differentiation of various cancer cells from normal ones. The primary tumor cells that were collected from two colorectal cancer patients, cancer cell lines (SW-403, Jurkat, and THP-1), and healthy peripheral blood mononuclear cells (PBMCs) were trapped first at the level of interdigitated microelectrodes with the help of dielectrophoresis. Correlation of the cells dielectric characteristics that was obtained via electrical impedance spectroscopy (EIS) allowed evident differentiation of the various types of cell. The differentiations were assigned to a “dielectric phenotype” based on their crossover frequencies. Finally, Randles equivalent circuit model was employed for highlighting the differences with regard to a series group of charge transport resistance and constant phase element for cancerous and normal cells.

Autoregressive parametric modeling combined ANOVA approach for label-free-based cancerous and normal cells discrimination

Label free based methods received huge interest in the field of bio cell characterizations because they do not cause any cell damage nor contribute any change in its compositions. This work takes a close outlook of cancerous cells discrimination from normal cells utilizing parametric modeling approach. Autoregressive (AR) modeling technique is used to fit the measured optical transmittance profiles of both cancer and normal cells. The transmitted light intensity, when passes through the cells, gets affected by their intercellular compositions and membrane properties. In this study, four types of cells: lung-cancerous and normal, liver-cancerous and normal, were suspended in their corresponding medium and their transmission characteristics were collected and processed. The AR coefficients of each type of the cell were analyzed with the statistical technique called Analysis of variance (ANOVA), which provided the significant coefficients. The poles extracted from the significant coefficients resulted in an improved demarcation for normal and cancer cells. These outcomes can be further utilized for cell classification using statistical tools.

Electrical Impedance Spectroscopy for Monitoring Chemoresistance of Cancer Cells

Electrical impedance spectroscopy (EIS) is an electrokinetic method that allows for the characterization of intrinsic dielectric properties of cells. EIS has emerged in the last decade as a promising method for the characterization of cancerous cells, providing information on inductance, capacitance, and impedance of cells. The individual cell behavior can be quantified using its characteristic phase angle, amplitude, and frequency measurements obtained by fitting the input frequency-dependent cellular response to a resistor-capacitor circuit model. These electrical properties will provide important information about unique biomarkers related to the behavior of these cancerous cells, especially monitoring their chemoresistivity and sensitivity to chemotherapeutics. There are currently few methods to assess drug resistant cancer cells, and therefore it is difficult to identify and eliminate drug-resistant cancer cells found in static and metastatic tumors. Establishing techniques for the real-time monitoring of changes in cancer cell phenotypes is, therefore, important for understanding cancer cell dynamics and their plastic properties. EIS can be used to monitor these changes. In this review, we will cover the theory behind EIS, other impedance techniques, and how EIS can be used to monitor cell behavior and phenotype changes within cancerous cells.

A theoretical study on real time monitoring of single cell mitosis with micro electrical impedance tomography

Real time monitoring of cell division, mitosis, at the single cell level, has value for many biomedical applications; such as developing optimal cancer treatments that target the cell division process. The goal of this theoretical study is to explore the feasibility of using Micro Electrical Impedance Tomography (MEIT) for real time monitoring of mitosis in a single cell, through imaging. MEIT employs a micro (single cell) scale electrode cage with electrodes placed around the cell. The electrodes deliver subsensory current and the consequential voltages on the electrodes are measured. An inverse image reconstruction algorithm uses the electric data from the electrodes to generate a map of electrical conductivity distribution in the chamber, which is the image. EIT is a well-known medical imaging technology that is simple to use but lacks good resolution. Therefore, it is not a-priori obvious that EIT has sufficient resolution to monitor single cell mitosis. To accomplish the goal of this study we have developed a mathematical model of MEIT of single cell mitosis, in which an in silico experiment provided the data for the MEIT image reconstruction. This theoretical study shows that MEIT can detect the outlines of the dividing cell during the various stages of mitosis (metaphase, anaphase and telophase) and, therefore, has potential as a technology for real time monitoring of single cell mitosis.