Faradaic Pixels for Precise Hydrogen Peroxide Delivery to Control M-Type Voltage-Gated Potassium Channels

Area of Science:

• Bioelectronics
• Redox Signaling
• Materials Science

Background:

• Hydrogen peroxide (H2O2) is crucial in physiological redox signaling.
• Biological pathways sensitive to H2O2 offer opportunities for bioelectronic device development.
• Controlling reactive oxygen species (ROS) levels is key for targeted biological modulation.

Purpose of the Study:

• To present a microfabricated device for controlled H2O2 generation and delivery.
• To investigate the use of poly(3,4-ethylenedioxythiophene) (PEDOT) as a cathode for H2O2 production.
• To demonstrate the modulation of H2O2-sensitive ion channels using the developed device.

Main Methods:

• Fabrication of a concentric pixel device with a peroxide-evolving cathode (PEDOT) and an anode ring.
• Utilizing faradaic reactions for controlled H2O2 generation and decomposition.
• Benchmarking device performance using electrochemical and optical assays, coupled with modeling.
• Prototyping by modulating Kv7.2/7.3 channels in Xenopus laevis oocytes.

Main Results:

• The device successfully generates localized and tunable gradients of H2O2 and oxygen.
• PEDOT selectively catalyzes the oxygen reduction reaction to produce H2O2.
• Demonstrated modulation of H2O2-sensitive Kv7 ion channels, highlighting the platform's potential.
• Validated the device's efficacy in a single-cell model.

Conclusions:

• The developed microfabricated device offers precise control over H2O2 delivery.
• PEDOT is a viable material for H2O2 delivery systems in organic bioelectronics.
• This technology paves the way for ROS-based bioelectronic applications and therapeutic strategies.