Raman imaging showing the impact of repeated temperature cycling on cryopreserved human iPSC viability
Description
Human induced pluripotent stem cells (hiPSCs) are an attractive cell source for regenerative medicine. For its widespread use as a starting material, a robust storage and distribution system in the frozen state is necessary. For this system, managing transient warming during storage and transport is essential, but how transient warming affects cells and the mechanisms involved are not yet fully understood. This study examined the influence of temperature cyclings (from -80 deg to -150 deg) on cryopreserved hiPSCs using a custom-made cryo Raman microscope to assess viability. Raman spectroscopy indicated the disappearance of mitochondrial cytochrome signals after thawing. A reduction in the mitochondrial membrane potential was detected using flow cytometry. The performance indices indicated a decrease in attachment effciency with an increase in the number of temperature cycles. This decrease was observed in the temperature cycle range above the glass transition temperature of the cryoprotectant. Raman observations captured an increase in the signal intensity of intracellular dimethyl sulfoxide (DMSO) during temperature cycles. Based on these results, the authors proposed a schematic illustration for cellular responses to temperature fluctuations, suggesting that temperature fluctuations above the glass- transition temperature trigger the movement of DMSO, leading to cytochrome c oxidation, mitochondrial damage, and caspase-mediated cell death. This enhances our understanding of the key events during cryopreservation and informs the development of quality control strategies for hiPSC storage and transport.
Release date
2026-11-02
Updated date
-
License
CC BY 4.0
Kind
Image data
based on Experiment
Number of Datasets
5
( Image datasets: 5,
Quantitative data datasets: 0 )
Masahiro Kino-Oka
, The University of Osaka
, Department of Biotechnology, Graduate School of Engineering
, Department of Biotechnology, Graduate School of Engineering