Human iPS Cell-Derived Cardiac Tissue Sheets: a Platform for Cardiac Regeneration.

OPINION STATEMENT: Stem cell therapy is a promising therapeutic option for severe cardiac diseases that are resistant to conventional therapies. To overcome the unsatisfactory results of most clinical researches on stem cell injections to an injured heart, we are developing bioengineered cardiac tissue grafts using pluripotent stem cell-derived cardiomyocytes and vascular cells. We have validated the functional benefits of mouse embryonic stem cell-derived and human induced pluripotent stem cell-derived cardiac tissue sheets (CTSs) in a rat myocardial infarction model. We further showed enhanced functional recovery and engraftment efficiency leading to de novo myocardium upon transplanting thick multi-layered CTSs that had gelatin hydrogel microspheres between the layers. We anticipate that the combination of pluripotent stem cell biology and tissue engineering will contribute to future stem cell therapies for severe heart diseases.