Cryopreservation of human induced pluripotent stem cells by using a new CryoLogic vitrification method.

Human induced pluripotent stem cells (hiPSCs) have the properties of differentiation potential and unlimited self-renewal. Developing efficient and highly safe methods to preserve hiPSCs is important due to they have demonstrated tremendous promise in disease etiology, drug discovery, and regenerative medicine applications. Traditionally, open systems for cell cryopreservation, such as conventional slow freezing and vitrification methods, were widespread application in the storage and transportation of hiPSCs. However, these two methods have such problems of low recovery rate and the risk of cross-contamination. Recently, closed systems for cell cryopreservation, such as CryoLogic Vitrification Method (CVM), were introduced to store and transport embryos. In this study, we developed a new friendly CVM by loading a small piece of hiPSCs colonies in the vitrification solution to the hook of Fiberplug to increase the cooling rate. To warm them, the CVM Fiberplug was immersed directly in a 37 °C warming solution for 1 min, and hiPSCs were then transferred to mTeSR1 medium. The result revealed that the new CVM had a high recovery rate and maintained the stemness and differentiation potential of hiPSCs. Our new CVM not only provide a safe way for hiPSCs preservation but also has a high survival rate in the storage of hiPSCs.