Recent progress in induced pluripotent stem cell-derived cardiac cell sheets for tissue engineering.

The past decade has witnessed remarkable development in tissue engineering technologies and stem cells. Our lab has developed a novel technology - "cell sheet technology" for tissue engineering. After the confluent cells are cultured on an innovative temperature-responsive culture dish, the cells can be harvested as an intact sheet by lowering temperature. We have successfully created multiple cell sheet-based tissues for therapies of a vast variety of diseases, in particular, myocardial diseases. On the other side, the discovery of human induced pluripotent stem cells (hiPSC) enables stable production of defined tissue-specific cell types and thus makes it possible to regenerate tissues or even organs for clinical application and in vitro drug screening/disease modeling. Recently, we have combined cell sheet technology and hiPSC-derived cardiac cells for fabrication of functional human cardiac tissues. This review summarizes ongoing challenges in this field and our progresses in solving issues, such as large scale culture of hiPSC-derived cardiac cells, elimination of undifferentiated iPSCs to decrease the risk of tumor formation as well as myocardial tissue fabrication technologies.