A Cell-Sparing Electric Field Stimulation Technique for High-Throughput Screening of Voltage-Gated Ion Channels

Voltage-gated ion channels mediate electrical dynamics in excitable tissues and are an important class of drug targets. Channels can gate in sub-millisecond timescales, show complex manifolds of conformational states, and often show state-dependent pharmacology. Mechanistic studies of ion channels typically involve sophisticated voltage-clamp protocols applied through manual or automated electrophysiology. Here, we develop all-optical electrophysiology techniques to study activity-dependent modulation of ion channels, in a format compatible with high-throughput screening. Using optical electrophysiology, we recapitulate many voltage-clamp protocols and apply to Nav1.7, a channel implicated in pain. Optical measurements reveal that a sustained depolarization strongly potentiates the inhibitory effect of PF-04856264, a Nav1.7-specific blocker. In a pilot screen, we stratify a library of 320 FDA-approved compounds by binding mechanism and kinetics, and find close concordance with patch clamp measurements. Optical electrophysiology provides a favorable tradeoff between throughput and information content for studies of NaV channels, and possibly other voltage-gated channels.

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Bioelectronics-on-a-chip for cardio myoblast proliferation enhancement using electric field stimulation

Biomaterials Research ◽

10.1186/s40824-020-00195-2 ◽

2020 ◽

Vol 24 (1) ◽

Author(s):

Ángel Aragón ◽

María Cebro-Márquez ◽

Eliseo Perez ◽

Antonio Pazos ◽

Ricardo Lage ◽

...

Keyword(s):

Cell Culture ◽

Electric Field ◽

Cell Density ◽

Electric Circuit ◽

Field Stimulation ◽

Culture Chamber ◽

Culture Dish ◽

Electric Field Stimulation ◽

Myoblast Proliferation ◽

A Cell

Abstract Background Cardio myoblast generation from conventional approaches is laborious and time-consuming. We present a bioelectronics on-a-chip for stimulating cells cardio myoblast proliferation during culture. Method The bioelectronics chip fabrication methodology involves two different process. In the first step, an aluminum layer of 200 nm is deposited over a soda-lime glass substrate using physical vapor deposition and selectively removed using a Q-switched Nd:YVO4 laser to create the electric tracks. To perform the experiments, we developed a biochip composed of a cell culture chamber fabricated with polydimethylsiloxane (PDMS) with a glass coverslip or a cell culture dish placed over the electric circuit tracks. By using such a glass cover slip or cell culture dish we avoid any toxic reactions caused by electrodes in the culture or may be degraded by electrochemical reactions with the cell medium, which is crucial to determine the effective cell-device coupling. Results The chip was used to study the effect of electric field stimulation of Rat ventricular cardiomyoblasts cells (H9c2). Results shows a remarkable increase in the number of H9c2 cells for the stimulated samples, where after 72 h the cell density double the cell density of control samples. Conclusions Cell proliferation of Rat ventricular cardiomyoblasts cells (H9c2) using the bioelectronics-on-a-chip was enhanced upon the electrical stimulation. The dependence on the geometrical characteristics of the electric circuit on the peak value and homogeneity of the electric field generated are analyzed and proper parameters to ensure a homogeneous electric field at the cell culture chamber are obtained. It can also be observed a high dependence of the electric field on the geometry of the electrostimulator circuit tracks and envisage the potential applications on electrophysiology studies, monitoring and modulate cellular behavior through the application of electric fields.

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Fluorescence Imaging of Electrically Stimulated Cells

CrossRef Listing of Deleted DOIs ◽

10.1177/1087057103258546 ◽

2003 ◽

Vol 8 (6) ◽

pp. 660-667 ◽

Cited By ~ 15

Author(s):

Paul Burnett ◽

Janet K. Robertson ◽

Jeffrey M. Palmer ◽

Richard R. Ryan ◽

Adrienne E. Dubin ◽

...

Keyword(s):

Membrane Potential ◽

Ion Channels ◽

Ion Channel ◽

High Throughput ◽

Pharmacological Intervention ◽

Voltage Gradient ◽

Channel Activity ◽

Voltage Gated ◽

Voltage Gated Ion Channels ◽

Gated Ion Channels

Designing high-throughput screens for voltage-gated ion channels has been a tremendous challenge for the pharmaceutical industry because channel activity is dependent on the transmembrane voltage gradient, a stimulus unlike ligand binding to G-protein-coupled receptors or ligand-gated ion channels. To achieve an acceptable throughput, assays to screen for voltage-gated ion channel modulators that are employed today rely on pharmacological intervention to activate these channels. These interventions can introduce artifacts. Ideally, a high-throughput screen should not compromise physiological relevance. Hence, a more appropriate method would activate voltage-gated ion channels by altering plasma membrane potential directly, via electrical stimulation, while simultaneously recordingthe operation of the channel in populations of cells. The authors present preliminary results obtained from a device that is designed to supply precise and reproducible electrical stimuli to populations of cells. Changes in voltage-gated ion channel activity were monitored using a digital fluorescent microscope. The prototype electric field stimulation (EFS) device provided real-time analysis of cellular responsiveness to physiological and pharmacological stimuli. Voltage stimuli applied to SK-N-SH neuroblastoma cells cultured on the EFS device evoked membrane potential changes that were dependent on activation of voltage-gated sodium channels. Data obtained using digital fluorescence microscopy suggests suitability of this system for HTS.

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Bioelectronics-on-a-chip for cardio myoblast proliferation enhancement using electric field stimulation.

10.21203/rs.3.rs-35992/v2 ◽

2020 ◽

Author(s):

Angel Aragon ◽

María Cebro-Márquez ◽

Eliseo Perez ◽

Antonio Pazos ◽

Ricardo Lage ◽

...

Keyword(s):

Cell Culture ◽

Electric Field ◽

Cell Density ◽

Electric Circuit ◽

Field Stimulation ◽

Culture Chamber ◽

Culture Dish ◽

Electric Field Stimulation ◽

Myoblast Proliferation ◽

A Cell

Abstract Background: Cardio myoblast generation from conventional approaches is laborious and time-consuming. We present a bioelectronics on-a-chip for stimulating cells cardio myoblast proliferation during culture. Method: The bioelectronics chip fabrication methodology involves two different process. In the first step, an aluminum layer of 200 nm is deposited over a soda-lime glass substrate using physical vapor deposition and selectively removed using a Q-switched Nd:YVO4 laser to create the electric tracks. To perform the experiments, we developed a biochip composed of a cell culture chamber fabricated with polydimethylsiloxane (PDMS) with a glass coverslip or a cell culture dish placed over the electric circuit tracks. By using such a glass cover slip or cell culture dish we avoid any toxic reactions caused by electrodes in the culture or may be degraded by electrochemical reactions with the cell medium, which is crucial to determine the effective cell-device coupling. Results: The chip was used to study the effect of electric field stimulation of Rat ventricular cardiomyoblasts cells (H9c2). Results shows a remarkable increase in the number of H9c2 cells for the stimulated samples, where after 72 hours the cell density double the cell density of control samples. Conclusions: Cell proliferation of Rat ventricular cardiomyoblasts cells (H9c2) using the bioelectronics-on-a-chip was enhanced upon the electrical stimulation. The dependence on the geometrical characteristics of the electric circuit on the peak value and homogeneity of the electric field generated are analyzed and proper parameters to ensure a homogeneous electric field at the cell culture chamber are obtained. It can also be observed a high dependence of the electric field on the geometry of the electrostimulator circuit tracks and envisage the potential applications on electrophysiology studies, monitoring and modulate cellular behavior through the application of electric fields

Download Full-text