Model-based assessment of temperature profiles in slow freezing for human induced pluripotent stem cells

•Developed a hybrid single-cell model for slow freezing of hiPS cells.•Conducted freeze/thaw experiments to obtain the parameter values of the model.•Assessed 16,206 temperature profiles using the hybrid model.•Showed fast-slow-fast cooling as suitable profile in freezing.•Confirmed the power of computer-aided approach for the regenerative therapy field. This work presents a model-based assessment of temperature profiles in slow freezing for human induced pluripotent stem (hiPS) cells. It is based on our single-cell model that can quantify temperature distribution in a vial, cell volume change through transmembrane water transport, and intracellular ice formation during freezing. This mechanistic model was extended to cover the cell survival rate through statistical modeling. Freeze/thaw experiments using hiPS cells provided the necessary parameter values. Given a temperature profile of freezing, the hybrid single-cell model could estimate the cell survival rate and required freezing time as the quality and productivity objectives, respectively. The model was applied to assess 16,206 temperature profiles. The simulation results suggested fast, slow, and fast cooling in the dehydration, nucleation-promoting, and further cooling zones, respectively. The work can be the first step toward establishing a design space of slow freezing of hiPS cells with an awareness of productivity and quality.