Induced Pluripotent Stem Cells for Clinical Use

Abstract

Induced pluripotent stem cells (iPSCs) are expected to be a novel cell source for regenerative medicine. Although iPSCs represented a significant breakthrough, there were many initial obstacles for their clinical use such as exogenous sequence insertions, inefficient cell reprogramming, tumorigenic properties, and animal-derived culture components. However, much progress has been made in iPSC generation since their development. The first human trial of iPSC-derived cell transplantation was conducted in September 2014, in which iPSC-derived retinal pigment epithelial cells were transplanted to a patient with macular degeneration. Because multiple clinical trials using iPSCs are expected in the near future, preparation of guidelines for generating and selecting iPSC lines suitable for clinical application is a pressing issue. For clinical use of iPSCs, many examinations for evaluating iPSC lines must be conduct‐ ed before transplantation. Different combinations of reprogramming factors, gene derivation vehicles, and types of donor cells can affect the quality of iPSCs, and guidelines for selecting the most appropriate iPSC lines for clinical use are under development. Furthermore, development of time-and cost-effective selection methods is essential for expanding iPSC transplantation therapy. In this chapter, we review methods for preparing human iPSCs before clinical use and the issues that are important for defining standard‐ ization of clinical-grade iPSCs.