Clinical grade iPS cells: need for versatile small molecules and optimal cell sources.

Adult mammals possess limited ability to regenerate their lost tissues or organs. The epoch-making strategy of inducing pluripotency in somatic cells incorporates multiple applications in regenerative medicine. However, concerns about the clinical translation of induced pluripotent stem (iPS) cells still exist because of the occurrence of aberrancies, even in genome integration-free methods. As cellular reprogramming is multi-gene-oriented, versatile, bioactive small molecules could concomitantly modulate the transcriptional machinery and aid the generation of clinical grade iPS cells. The availability of optimal cell sources has additional influence on the clinical translation of iPS cells. Herein we provide a critical overview of methods and cell sources available for iPS cell production. We think the review will be a useful resource for researchers who aim to develop small molecules for speeding up the journey of iPS cells from the laboratory to the clinic.