Electrical Impedance Monitoring of C2C12 Myoblast Differentiation on an Indium Tin Oxide Electrode

Application of bioelectrical impedance detection techniques: Cells and tissues

Pathological conditions in organisms often arise from various cellular or tissue abnormalities, including dysregulation of cell numbers, infections, aberrant differentiation, and tissue pathologies such as lung tumors and skin tumors. Thus, developing methods for analyzing and identifying these biological abnormalities presents a significant challenge. While traditional bioanalytical methods such as flow cytometry and magnetic resonance imaging are well-established, they suffer from inefficiencies, high costs, complexity, and potential hazards. To address these challenges, bioelectrical impedance detection technology, which leverages the electrical properties of biological cells and tissues to extract relevant biomedical information, has garnered considerable attention in the field of biological detection due to its affordability, convenience, non-invasiveness, and label-free nature. This article first provides a brief introduction to the principles of bioelectrical impedance and related detection techniques, as well as the equivalent circuit models and numerical simulation models developed at the cellular and tissue levels. Next, this article delves into the applications of bioelectrical impedance technology at the cellular level, including recent advancements in cell counting, classification, concentration detection, differentiation, and infection, thereby enriching previous literature reviews from a multicellular perspective. In addition, this article highlights the applications of bioelectrical impedance technology in relevant tissues including muscle, skin, lungs, and so on. Finally, the article explores the future opportunities and challenges of bioelectrical impedance detection and analysis technology, focusing on interdisciplinary research areas and data-driven intelligent analysis, offering researchers broader research directions and perspectives.

Electrical impedance sensing in stem cell research: Insights, applications, and future directions

The exceptional differentiation abilities of stem cells make them ideal candidates for cell replacement therapies. Considering their great potential, researchers should understand how stem cells interact with other cell types. The production of high-quality differentiated cells is crucial for favorable treatment and makes them an ideal choice for clinical applications. Label-free stem cell monitoring approaches are anticipated to be more effective in this context, as they ensure quality of differentiation while preserving the therapeutic potential. Electric cell-substrate impedance sensing (ECIS) is a nonintrusive technique that enables cell quantification through continuous monitoring of adherent cell behavior using electronic transcellular impedance measurements. This technique also facilitates the study of cell growth, motility, differentiation, drug effects, and cell barrier functions. Therefore, numerous studies have identified ECIS as an effective method for monitoring stem cell quality and differentiation. In this review, we discuss the current understanding of ECIS's achievements in examining cell behaviors and the potential applications of ECIS arrays in preclinical stem cell research. Moreover, we highlight our present knowledge concerning ECIS's contributions in examining cell behaviors and speculate about the future uses of ECIS arrays in preclinical stem cell research. This review also aims to stimulate research on electrochemical biosensors for future applications in regenerative medicine.

Biocompatibility and Electrical Stimulation of Skeletal and Smooth Muscle Cells Cultured on Piezoelectric Nanogenerators

Nanogenerators are interesting for biomedical applications, with a great potential for electrical stimulation of excitable cells. Piezoelectric ZnO nanosheets present unique properties for tissue engineering. In this study, nanogenerator arrays based on ZnO nanosheets are fabricated on transparent coverslips to analyse the biocompatibility and the electromechanical interaction with two types of muscle cells, smooth and skeletal. Both cell types adhere, proliferate and differentiate on the ZnO nanogenerators. Interestingly, the amount of Zn ions released over time from the nanogenerators does not interfere with cell viability and does not trigger the associated inflammatory response, which is not triggered by the nanogenerators themselves either. The local electric field generated by the electromechanical nanogenerator–cell interaction stimulates smooth muscle cells by increasing cytosolic calcium ions, whereas no stimulation effect is observed on skeletal muscle cells. The random orientation of the ZnO nanogenerators, avoiding an overall action potential aligned along the muscle fibre, is hypothesised to be the cause of the cell-type dependent response. This demonstrates the need of optimizing the nanogenerator morphology, orientation and distribution according to the potential biomedical use. Thus, this study demonstrates the cell-scale stimulation triggered by biocompatible piezoelectric nanogenerators without using an external source on smooth muscle cells, although it remarks the cell type-dependent response.

Aluminium Oxide Thin-Film Based In Vitro Cell-Substrate Sensing Device for Monitoring Proliferation of Myoblast Cells

We demonstrate cell-substrate interaction on aluminium oxide thin-film in metal-insulator-metal structure followed by the change in dielectric characteristics of Al₂O₃ as a function of progression of cellular growth. The theoretical calculation of the fabricated biosensor reveals that the changes in the intrinsic elemental parameters are mainly attributed to the cell-induced behavioural changes.

Arsenic Stimulates Myoblast Mitochondrial Epidermal Growth Factor Receptor to Impair Myogenesis

Arsenic exposure impairs muscle metabolism, maintenance, progenitor cell differentiation, and regeneration following acute injury. Low to moderate arsenic exposures target muscle fiber and progenitor cell mitochondria to epigenetically decrease muscle quality and regeneration. However, the mechanisms for how low levels of arsenic signal for prolonged mitochondrial dysfunction are not known. In this study, arsenic attenuated murine C2C12 myoblasts differentiation and resulted in abnormal undifferentiated myoblast proliferation. Arsenic prolonged ligand-independent phosphorylation of mitochondrially localized epidermal growth factor receptor (EGFR), a major driver of proliferation. Treating cells with a selective EGFR kinase inhibitor, AG-1478, prevented arsenic inhibition of myoblast differentiation. AG-1478 decreased arsenic-induced colocalization of pY845EGFR with mitochondrial cytochrome C oxidase subunit II, as well as arsenic-enhanced mitochondrial membrane potential, reactive oxygen species generation, and cell cycling. All of the arsenic effects on mitochondrial signaling and cell fate were mitigated or reversed by addition of mitochondrially targeted agents that restored mitochondrial integrity and function. Thus, arsenic-driven pathogenesis in skeletal muscle requires sustained mitochondrial EGFR activation that promotes progenitor cell cycling and proliferation at the detriment of proper differentiation. Collectively, these findings suggest that the arsenic-activated mitochondrial EGFR pathway drives pathogenic signaling for impaired myoblast metabolism and function.

INK-JET PRINTED STRETCHABLE SENSORS FOR CELL MONITORING UNDER MECHANICAL STIMULI: A FEASIBILITY STUDY

Impedance-based sensors represent a promising tool for cell monitoring to improve current invasive biological assays. A novel research field is represented by measurements performed in dynamic conditions, monitoring cells (e.g., myocytes) for which the mechanical stimulus plays an important role for promoting maturation. In this picture, we applied printed and stretchable electronics principles, developing a system able to evaluate cells adhesion during substrate cyclic strain. Cytocompatible and stretchable sensors were ink-jet printed using carbon-based ink on crosslinked poly([Formula: see text]-caprolactone) electrospun mats. Moreover, a customized stretching device was produced, with a complete user interface to control testing condition, validated in order to correlate impedance changes with myoblasts — i.e., myocytes precursors — adhesion. Overall system sensitivity was evaluated using three different cell concentrations and DAPI imaging assay was performed to confirm myoblast adhesion. Preliminary results showed the possibility to correlate an average increase of impedance magnitude of 1[Formula: see text]k[Formula: see text] every 15,000 cells/cm2 seeded, suggesting the possibility to discriminate between different cell concentrations, with a sensitivity of 80[Formula: see text]m[Formula: see text]/(cells/cm2). In conclusion, the present system might be generalized in the development of future applications, including the differentiation process of cardiac myocytes with the aid of mechanical stimuli.

Cell-based biosensors: Recent trends, challenges and future perspectives

Existing at the interface of biology and electronics, living cells have been in use as biorecognition elements (bioreceptors) in biosensors since the early 1970s. They are an interesting choice of bioreceptors as they allow flexibility in determining the sensing strategy, are cheaper than purified enzymes and antibodies and make the fabrication relatively simple and cost-effective. And with advances in the field of synthetic biology, microfluidics and lithography, many exciting developments have been made in the design of cell-based biosensors in the last about five years. 3D cell culture systems integrated with electrodes are now providing new insights into disease pathogenesis and physiology, while cardiomyocyte-integrated microelectrode array (MEA) technology is set to be standardized for the assessment of drug-induced cardiac toxicity. From cell microarrays for high-throughput applications to plasmonic devices for anti-microbial susceptibility testing and advent of microbial fuel cell biosensors, cell-based biosensors have evolved from being mere tools for detection of specific analytes to multi-parametric devices for real time monitoring and assessment. However, despite these advancements, challenges such as regeneration and storage life, heterogeneity in cell populations, high interference and high costs due to accessory instrumentation need to be addressed before the full potential of cell-based biosensors can be realized at a larger scale. This review summarizes results of the studies that have been conducted in the last five years toward the fabrication of cell-based biosensors for different applications with a comprehensive discussion on the challenges, future trends, and potential inputs needed for improving them.

Electrochemical Impedance Characterization of Cell Growth on Reduced Graphene Oxide–Gold Nanoparticles Electrodeposited on Indium Tin Oxide Electrodes

The improved binding ability of graphene–nanoparticle composites to proteins or molecules can be utilized to develop new cell-based assays. In this study, we fabricated reduced graphene oxide–gold nanoparticles (rGO-AuNP) electrodeposited onto a transparent indium tin oxide (ITO) electrode and investigated the feasibility of the electrochemical impedance monitoring of cell growth. The electrodeposition of rGO–AuNP on the ITO was optically and electrochemically characterized in comparison to bare, rGO-, and AuNP-deposited electrodes. The cell growth on the rGO–AuNP/ITO electrode was analyzed via electrochemical impedance measurement together with the microscopic observation of HEK293 cells transfected with a green fluorescent protein expression vector. The results showed that rGO–AuNP was biocompatible and induced an increase in cell adherence to the electrode when compared to the bare, AuNP-, or rGO-deposited ITO electrode. At 54 h cultivation, the average and standard deviation of the saturated normalized impedance magnitude of the rGO–AuNP/ITO electrode was 3.44 ± 0.16, while the value of the bare, AuNP-, and rGO-deposited ITO electrode was 2.48 ± 0.15, 2.61 ± 0.18, and 3.01 ± 0.25, respectively. The higher saturated value of the cell impedance indicates that the impedimetric cell-based assay has a broader measurement range. Thus, the rGO–AuNP/ITO electrode can be utilized for label-free and real-time impedimetric cell-based assays with wider dynamic range.

A real-time monitoring platform of myogenesis regulators using double fluorescent labeling

Real-time, quantitative measurement of muscle progenitor cell (myoblast) differentiation is an important tool for skeletal muscle research and identification of drugs that support skeletal muscle regeneration. While most quantitative tools rely on sacrificial approach, we developed a double fluorescent tagging approach, which allows for dynamic monitoring of myoblast differentiation through assessment of fusion index and nuclei count. Fluorescent tagging of both the cell cytoplasm and nucleus enables monitoring of cell fusion and the formation of new myotube fibers, similar to immunostaining results. This labeling approach allowed monitoring the effects of Myf5 overexpression, TNFα, and Wnt agonist on myoblast differentiation. It also enabled testing the effects of surface coating on the fusion levels of scaffold-seeded myoblasts. The double fluorescent labeling of myoblasts is a promising technique to visualize even minor changes in myogenesis of myoblasts in order to support applications such as tissue engineering and drug screening.