Advances in Conductive Nanomaterials for Cardiac Arrhythmia and Future Directions in Bioevaluation Strategies.

Cardiac arrhythmia (CA), characterized by irregular heart rhythms, affects nearly 90% of individuals with cardiovascular diseases. Commonly triggered by myocardial infarction (MI) or ion channel dysfunctions, CA is traditionally treated using pacemakers, cardioversion, ablation, and anti-arrhythmic drugs. Recently, emerging strategies like cardiac patches and injectable formulations with conductive nanomaterials (CNMs) have shown promise in restoring cardiac rhythm post-MI. This review explores CNMs-such as gold nanoparticles, carbon nanotubes, and conjugated polymers-that mimic the electrical and mechanical properties of native cardiac tissue. While in vitro studies show encouraging results, translating CNMs to clinical settings faces challenges. Few studies have assessed their safety and efficacy in rodent models, and none in larger animals. This gap stems from the complexity and ethical hurdles of large animal research. To address this, the review advocates using small animal models like zebrafish, Drosophila melanogaster, and Caenorhabditis elegans. These models offer insights into pharmacokinetics, pharmacodynamics, genetic effects, and cardiac parameters such as ejection fraction and cardiac output-data often unattainable in vitro. Such platforms can better evaluate CNMs' safety and efficacy than 2D/3D cultures, accelerating progress toward clinical application.