为了对细胞的最优化低温保存方案提供理论预测,考虑细胞内溶液为非理想溶液,建立了一个新的胞内冰晶成核与生长模型.与基于修正的Mazur方程的理想溶液模型相比,新模型进一步耦合了Fahy的水输运方程与冰晶成核、扩散控制的冰晶生长理论.使用改进后的胞内冰模型详细研究了以甘油为低温保护剂的老鼠卵细胞的冷冻过程.通过比较分析两种模型下降温速率、初始甘油浓度对胞内溶液体积、胞内冰晶体积份额等的影响,我们得出较低的降温速率下,两种模型预测的结果具有比较显著的差异,而高降温速率条件下,两种模型预测的结果一致.
To predict the optimal cryopreservation protocol for biological cells, a new intracellular ice formation model was developed by incorporating the nonideality into the intracellular solution. Compared with the ideal solution model based on the modified Mazur's water transport equation, the new model further coupled Fahy's water transport equation, ice nucleation, and the diffusion-limited ice growth theory. The new model was then used to study the freezing process of mouse oocyte in the presence of glycerol as a cryoprotective agent. Through the comparative analysis of the influence of cooling rate and initial glycerol concentration on the intracellular solution volume and the crystallized volume fraction under these two models, it was found that the predictions by these two models had significant difference at low cooling rate, while they are consistent at high cooling rate.