Efficient derivation and banking of clinical-grade human embryonic stem cell lines in accordance with Japanese regulations

Introduction: We recently established clinical-grade human embryonic stem cell (hESC) line KthES11 in accordance with current good manufacturing practice standards in Japan. Despite this success, the establishment efficiency was very low at 7.1% in the first period.Methods: To establish clinical-grade hESC lines, we used xeno-free chemically defined medium StemFit AK03N with the LM-E8 fragments instead of feeder cells. The protocol was then optimized, especially in the early culture phase.Results: We established five hESC lines (KthES12, KthES13, KthES14, KthES15, and KthES16) with 45.5% efficiency. All five hESC lines showed typical hESC-like morphology, a normal karyotype, pluripotent state, and differentiation potential for all three germ layers. Furthermore, we developed efficient pro-cedures to prepare master cell stocks for clinical-grade hESC lines and an efficient strategy for quality control testing.Conclusions: Our master cell stocks of hESC lines may contribute to therapeutic applications using hu-man pluripotent stem cells in Japan and other countries.(c) 2022, The Japanese Society for Regenerative Medicine. Production and hosting by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).