Highly Conductive, Stretchable, and Cell-Adhesive Hydrogel by Nanoclay Doping

Area of Science:

• Materials Science
• Biomedical Engineering
• Neuroscience

Background:

• Advanced brain-machine interfaces require conductive materials that emulate tissue characteristics.
• Existing materials often lack the necessary combination of conductivity, stretchability, and biocompatibility.

Purpose of the Study:

• To engineer a multinetwork hydrogel with tissue-mimicking properties for seamless brain-machine interfaces.
• To achieve high electrical conductivity, exceptional stretchability, and a tissue-like elastic modulus.

Main Methods:

• Utilized an in-scaffold polymerization approach with Laponite nanoclay as a support for secondary polymer networks.
• Synthesized poly(ethylene-3,4-diethoxy thiophene) within the Laponite scaffold.
• Coated the conductive hydrogel with adhesive peptides and dextran sulfate.

Main Results:

• Achieved an electrical conductivity of 26 S m^-1 and stretchability of 800% with a 15 kPa elastic modulus.
• Demonstrated that Laponite significantly enhances conductivity without compromising stretchability.
• Showcased successful attachment, proliferation, and neuronal differentiation of human induced pluripotent stem cells on the hydrogel surface.
• Confirmed compatibility with extrusion printing for fabricating neurostimulating electrodes.

Conclusions:

• The developed conductive hydrogel offers a unique combination of properties essential for advanced neuroprosthetics.
• The in-scaffold polymerization method provides a versatile platform for creating biomimetic conductive materials.
• This material holds significant promise for developing next-generation, tissue-mimetic neurostimulating electrodes.