Maturation of Human iPSC-derived Cardiac Microfiber with Electrical Stimulation Device.

This paper describes an electrical stimulation system for maturing microfiber-shaped cardiac tissue (cardiac microfibers, CMFs). The system enables stable culturing of CMFs with electrical stimulation by placing the tissue between electrodes. The electrical stimulation device provides a uniform an electric field covering whole CMFs within the stimulation area and can control the beating of the cardiac microfibers. In addition, CMFs under electrical stimulation with different frequencies are examined to evaluate the maturation levels by their sarcomere lengths, electrophysiological characteristics, and gene expression. Sarcomere elongation (14% increase compared to control) is observed at day 10, and a significant upregulation of electrodynamic properties such as GJA1 and KCNJ2 (max 4-fold increase compared to control) is observed at day 30. These results suggest that electrically stimulated cultures can accelerate the maturation of microfiber-shaped cardiac tissues compared to those without electrical stimulation. This model would contribute to the pathological research of unexplained cardiac diseases and pharmacologic testing by stably constructing matured CMFs. This article is protected by copyright. All rights reserved.