Transduction of cell-penetrating peptides into induced pluripotent stem cells.

Induced pluripotent stem (iPS) cells have recently been generated by Yamanaka's group, and then followed by others. iPS cells are expected to have clinical applications including an important role in regenerative medicine. This study focused on the cell-penetrating peptides (CPPs) for differentiation or functional application of iPS cells, because several transduction domains can deliver a large size-independent variety of molecules into cells. Two CPPs, Texas Red-R8 and Rhodamine-TAT, were generated as representative CPPs and these CPPs were tested to determine their ability to penetrate the membrane of iPS cells. Both CPPs were transduced in iPS cells through macropinocytosis classified in endocytosis within 2 h in a manner consistent with many other cells, and no cytotoxicity and influence on their undifferentiated state was observed. In conclusion, CPPs can be utilized for their differentiation or functional application in iPS cells.