High-quality Cardiac Tissue (IMAGE) Kyoto University Caption We obtained high-quality cardiac tissue-like constructs (CTLCs) by cultivating hiPSC-CMs on aligned nanofibers made of biodegradable polymer. We show that multi-layered and elongated CMs could promptly be organized at high density along aligned nanofibers, resulting in upregulated cardiac biomarkers and enhanced cardiac functions. When used for drug assessment, CTLCs were much more robust than the 2D conventional control. We used the CTLCs to simulate the repairing of disconnected and arrhythmia CMs in vitro. When used to repair injured rat hearts, the CTLCs showed excellent operability leading to favorable heart function recovery. Credit Kyoto University iCeMS Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.