Water-transport and intracellular ice formation of human adipose-derived stem cells during freezing

The key to optimizing the cryopreservation strategy of human adipose-derived stem cells (hADSCs) is to identify the biophysical characteristics during freezing. Systematic freezing experiments were conducted under a cryo-microscope system to investigate the cryoinjury mechanism for hADSCs at different cooling rates. By simultaneously fitting morphological change data to the water-transport equation at 5, 10 and 20 °C/min, the plasma membrane hydraulic conductivity, Lpg, and activation energy, ELp, were determined. Moreover, the optimal cooling rate was also predicted by using mathematical model methods. Additionally, the surface-catalyzed nucleation (SCN) parameters were calculated by fitting in numerical models, Ω0SCN and k0SCN were determined at cooling rates of 30, 45 and 60 °C/min. These results may provide potential application value for cryopreservation of hADSCs.