Fractal form PEDOT/Au assemblies as thin-film neural interface materials

Area of Science:

• Neural Engineering
• Materials Science
• Biomedical Engineering

Background:

• Electrically conducting polymers are crucial for neural interfaces, enabling electrical and ionic charge transfer for cell stimulation.
• Topographically functionalized or neuromorphic materials can guide axon growth and improve in vitro neuroelectrode interfacing.

Purpose of the Study:

• To develop a novel method for creating conducting polymer/gold assemblies for neural engineering applications.
• To investigate the electrochemical and topographical properties of these assemblies.
• To evaluate their potential in promoting neural cell growth and function.

Main Methods:

• A combinational sputter and spin coating technique was used to form multilayered poly(3,4-ethylenedioxythiophene)/gold (PEDOT/Au) substrates.
• Electrochemical conditioning was employed to create fractal-like gold assemblies.
• Electrochemical properties (charge storage capacity, impedance) and neurite outgrowth in a mixed ventral mesencephalon cell population were assessed.

Main Results:

• Multilayered PEDOT/Au substrates exhibited enhanced electrochemical properties dependent on layer number.
• Electrochemical conditioning resulted in fractal-like gold assemblies, significantly altering film characteristics.
• PEDOT/Au assemblies displayed unique topography, high charge storage capacity (34.9 ± 2.6 mC cm⁻²), and low impedance (30 ± 2 Ω at 1 kHz).
• These assemblies promoted neurite outgrowth and increased the neurons/astrocytes ratio in vitro.

Conclusions:

• The developed PEDOT/Au assemblies possess advantageous electrochemical and topographical features for neural interfaces.
• These biomimetic neuromorphic materials show potential for enhancing neural interfacing and promoting neural regeneration.
• The findings indicate PEDOT/Au assemblies as promising candidates for engineering advanced, electrically conductive neural interface systems.