Beyond Transconductance: Cell-Polymer Coupling Determines Fidelity in Action Potential Recording via...

Area of Science:

• Bioelectronics
• Materials Science
• Cellular Electrophysiology

Background:

• Organic bioelectronic transistors offer biocompatibility and softness for studying cellular electrophysiology.
• Current device benchmarking focuses on electrical properties, neglecting crucial interfacial factors for signal fidelity.
• Poly(g2T-TT) is a promising organic mixed ionic-electronic conductor for Organic Electrochemical Transistors (OECTs).

Purpose of the Study:

• To evaluate p(g2T-TT)-based OECTs for recording action potentials (APs) from human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).
• To compare the signal transduction fidelity of p(g2T-TT) with P3HT-based Electrolyte-Gated Field-Effect Transistors (EGOFETs).
• To investigate the role of interfacial properties in bioelectronic signal transduction.

Main Methods:

• Fabrication and testing of p(g2T-TT)-based OECTs for AP recording from hiPSC-CMs.
• Comparison of AP waveforms recorded by p(g2T-TT) OECTs and P3HT EGOFETs.
• Immunofluorescence imaging to assess cell-device adhesion.

Main Results:

• AP signal transduction was observed with p(g2T-TT) OECTs, but waveforms lacked expected morphology.
• P3HT-based EGOFETs recorded APs with higher fidelity compared to p(g2T-TT) OECTs.
• Improved cell adhesion was observed on P3HT compared to p(g2T-TT), indicating weaker cell-device coupling for p(g2T-TT).

Conclusions:

• High electrical performance and biocompatibility alone do not guarantee high-fidelity AP signal transduction.
• Interfacial properties, particularly cell-device coupling, are critical determinants of bioelectronic transduction fidelity.
• Rational design of polymers and platforms focusing on interfacial characteristics is essential for reliable in vitro and in vivo cellular electrophysiology.