title: Sensitivity of human embryonic stem cells to different conditions during cryopreservation.
abstract: Low cell recovery rate of human embryonic stem cells (hESCs) resulting from cryopreservation damages leads to the difficulty in their successful commercialization of clinical applications. Hence in this study, sensitivity of human embryonic stem cells (hESCs) to different cooling rates, ice seeding and cryoprotective agent (CPA) types was compared and cell viability and recovery after cryopreservation under different cooling conditions were assessed. Both extracellular and intracellular ice formation were observed. Reactive oxidative species (ROS) accumulation of hESCs was determined. Cryopreservation of hESCs at 1 °C/min with the ice seeding and at the theoretically predicted optimal cooling rate (TPOCR) led to lower level of intracellular ROS, and prevented irregular and big ice clump formation compared with cryopreservation at 1 °C/min. This strategy further resulted in a significant increase in the hESC recovery when glycerol and 1,2-propanediol were used as the CPAs, but no increase for Me2SO. hESCs after cryopreservation under all the tested conditions still maintained their pluripotency. Our results provide guidance for improving the hESC cryopreservation recovery through the combination of CPA type, cooling rate and ice seeding.
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China. Electronic address: xuyanqing1006@hotmail.com.
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China. Electronic address: zhangliang@ipe.ac.cn.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China. Electronic address: jdxu@ipe.ac.cn.
authors.forename: Jiandong
authors.initials: J
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China. Electronic address: ypwei@ipe.ac.cn.
authors.forename: Yuping
authors.initials: Y
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China. Electronic address: xuxia@ipe.ac.cn.
authors.forename: Xia
authors.initials: X
authors.lastname: Xu
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology; D000066449:Human Embryonic Stem Cells / Q000166:cytology*; D006801:Humans
chemical_list: D003451:Cryoprotective Agents
keywords: Cryopreservation; Ice formation; Reactive oxidative species; Recovery; hESCs