University System of Maryland

University of Shanghai for Science and Technology

Weijie Li

Baolin Liu

Qin Qi

Bin Jiang

Yanbin Qin

Zhixin Li

Xiaoming He

Jing Shen

Hongli Yan

A method, system and device for programmed cell freezing is disclosed. The method includes: S1, acquiring a cooling rate k and a temperature distribution function T=a×h+b×h+c of a heat preservation chamber containing liquid nitrogen; S2, controlling a cell preservation tube to lower in the chamber at a speed of v=(k−b)/2ah, and acquiring temperatures Tand Tinside and outside the tube at a same time and at a same height in real time during the lowering of the tube; S3, determining whether a difference Δt between Tand Texceeds a preset temperature difference threshold, if yes, proceeding to S4, and if no, proceeding to S2 until the tube reaches a position corresponding to a preset temperature T; and S4, controlling the cell preservation tube to stop until the difference Δt between Tand Tis less than or equal to the temperature difference threshold, and continuing S2.

Method, system and device for programmed cell freezing

Human induced pluripotent stem cells (hiPSCs) possess tremendous potential for tissue regeneration and banking hiPSCs by cryopreservation for their ready availability is crucial to their widespread use. However, contemporary methods for hiPSC cryopreservation are associated with both limited cell survival and high concentration of toxic cryoprotectants and/or serum. The latter may cause spontaneous differentiation and introduce xenogeneic factors, which may compromise the quality of hiPSCs. Here, sand from nature is discovered to be capable of seeding ice above −10° C., which enables cryopreservation of hiPSCs with no serum, minimized cryoprotectant, and high cell survival. Furthermore, the cryopreserved hiPSCs retain high pluripotency and functions judged by the pluripotency marker expression, cell cycle analysis, and capability of differentiation into the three germ layers. This unique sand-mediated cryopreservation method may greatly facilitate the convenient and ready availability of high-quality hiPSCs and probably many other types of cells/tissues for the emerging cell-based translational medicine.

System, device, and method for cell cryopreservation via sand-mediated ice seeding

Growing community of inventors

Shanghai, China

Weijie Li