Current status of myocardial regeneration and cell transplantation.

Recent studies have shown that cardiomyocytes can be induced to differentiate from several types of stem cells. Techniques to purify and transplant stem-cell-derived cardiomyocytes have also been developed, and the transplanted cells have been demonstrated to reside in the recipient hearts for long periods. Recently, cardiomyocyte cell sheets enabling transplantation of viable tissue have been reported. Promising results have also been obtained using cytokines to mobilize stem cells in vivo as a potential treatment for heart failure. However, a number of hurdles remain in the quest to treat heart failure by cell transplantation without the need for a donor at the preclinical stage. In the next phase, the field needs to develop innovations to specifically differentiate cardiomyocytes from stem cells, to purify cardiomyocytes from contaminating cells in a cell mixture using a high-throughput method, and to establish and maintain artificial regenerated tissue using tissue engineering for transplantation.