Future prospects for regenerated heart using induced pluripotent stem cells.

Induced pluripotent stem cell (iPSC) generation is an epoch-making technology. The potential applications for iPSCs are wide-ranging from in vitro disease models to drug discovery. For regenerative medicine in particular, the technology provides great hope for patients with incurable diseases or potentially fatal disorders such as heart failure (HF). However, the true realization of that promise for HF remains uncertain and moving toward the clinical application of iPSCs needs to be stepwise and careful. The establishment of "safe" iPSCs must be a major premise, while genome integration-free and oncogene-free reprogramming is also necessary. Teratoma formation also remains a risk with undifferentiated iPSCs, but it must not happen in patients' bodies. Thus, regardless of the target organ, the differentiated cells from iPSCs must be purified to exclude any possibility of tumorigenicity. The transplantation strategies used for iPSC-derived cells are very important for the recovery of lost cardiac function. Longer engraftment of transplanted iPSCs-derived cardiomyocytes is essential particularly because their survival could be hampered by ischemia, inflammation, apoptosis, immunological rejection, and other cardiac phenomena. Providing these multistep solutions will open the new frontier of regenerative therapies with iPSCs for patients with severe HF.