Cardiomyocyte sheet stacking using fibrin enables high-speed construction of three-dimensional myocardial tissue and high transplantation efficiency.

Despite the development of three-dimensional (3D) tissues that promises remarkable advances in myocardial therapies and pharmaceutical research, vascularization is required for the repair of damaged hearts using cardiac tissue engineering. In this study, we developed a method for rapid generation of a 3D cardiac tissue, with extremely high engraftment efficiency, by stacking cardiomyocyte sheets using fibrin as an adhesive. Cell sheets were created by peeling off confluent cultured cells from a culture dish grafted with a polymer that induced surface hydrophilicity in response to low temperatures. The high engraftment rate was attributed to the retention of the adhesive protein. The multistacked vascularized cell sheets prepared using fibrin, when transplanted into the subcutaneous tissue and at myocardial infarction site in rats, yielded a transplanted 3D myocardial tissue. Furthermore, multilayered cardiomyocyte sheets were transplanted twice at 1 week intervals to create a 3D myocardial tissue. Our data suggest that fibrin-based rapidly layered cell sheets can advance tissue-engineered transplantation therapy and should aid the development of next-generation tissue-engineered products in the fields of regenerative medicine and drug screening.