High-speed mechano-active multielectrode array for investigating rapid stretch effects on cardiac tissue

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Cellular Electrophysiology

Background:

• Investigating mechano-electric coupling (MEC) in cardiac cells requires systems that mimic in-vivo strain patterns while monitoring electrical activity.
• Existing experimental setups often lack the capability for dynamic strain application and simultaneous electrophysiological recording.

Purpose of the Study:

• To develop and validate a novel experimental system for assessing MEC in engineered cardiac tissues.
• To investigate the influence of dynamic mechanical strain on cardiac impulse conduction.

Main Methods:

• A motor-less device, the mechano-active multielectrode-array (MaMEA), was engineered using polydimethylsiloxane (PDMS) substrates.
• The MaMEA incorporates dielectric actuators (DEAs) for controlled uniaxial strain and ion-implanted gold electrodes for electrical recording.
• Bioengineered cardiomyocyte strands were subjected to dynamic strain cycles (up to 18 s⁻¹) to measure impulse conduction.

Main Results:

• Cardiac impulse conduction demonstrated a linear dependence on static strain, consistent with cable theory.
• Unexpectedly, strain rate was found to have no significant impact on cardiac impulse conduction.
• The MaMEA system enables high-throughput MEC investigations under spatially patterned mechanical perturbations.

Conclusions:

• The MaMEA device provides a robust platform for studying MEC in cardiac tissues under physiologically relevant conditions.
• Findings highlight the distinct roles of static strain and strain rate in modulating cardiac electrophysiology.
• This technology facilitates systematic, high-throughput analysis of MEC, advancing our understanding of cardiac mechanics and electrical function.