Biologically derived soft conducting hydrogels using heparin-doped polymer networks

Area of Science:

• Biomaterials Science
• Materials Chemistry
• Bioelectronics

Background:

• Flexible electronics are crucial for biointerfaces, but existing materials are too stiff compared to native tissues.
• Electronically excitable tissues require compliant materials for effective integration.

Purpose of the Study:

• To develop novel ultracompliant hydrogel networks with hybrid electronic/ionic conductivity.
• To create a biointerface material that matches the mechanical properties of soft, excitable tissues.

Main Methods:

• Utilized photo-cross-linkable heparin-methacrylate hydrogels as templates.
• Fabricated in situ polymerized polyaniline structures within heparin hydrogels.
• Characterized the electrical impedance and mechanical storage moduli of the resulting dual networks.

Main Results:

• Heparin/polyaniline hydrogel dual networks demonstrated low impedance (Z = 4.17 Ω at 1 kHz) and ultracompliant storage moduli (G' = 900 ± 100 Pa).
• Material conductivity is tunable based on polyaniline's oxidation state and microstructure.
• The hydrogels supported murine myoblast attachment, proliferation, and differentiation without surface modification.

Conclusions:

• Heparin/polyaniline hydrogel networks possess suitable physical properties for electronic biointerfaces.
• These materials effectively bridge the mechanical mismatch between electronic components and soft tissues.
• The developed hydrogels show promise for applications in electronically active biointerfaces and regenerative medicine.