多组分冷冻保护剂导入神经干细胞球的传质模拟

Mass Transfer Simulation of Multiple Cryoprotectants Loading into Neurosphere

基于Maxwell-Stefan方程和两参数模型构建了神经干细胞球多组分保护剂导入模型,并模拟了多组分保护剂导入过程中细胞内外浓度及细胞膜两侧浓差的时空分布。在此基础上系统分析了多组分浓度配比、神经球尺寸、保护剂导入方式对传质渗透过程的影响。结果表明,多组分保护剂导入神经球过程中出现"逆梯度扩散"现象,胞内浓度变化总是滞后于胞外浓度变化,细胞膜两侧浓差呈现先增大后减少的趋势。改变保护剂组分的浓度配比时,不同组分的渗透特性变化规律不同。此外,神经球尺寸对中心处细胞的浓度时空分布影响显著,分步导入和连续导入能够减缓保护剂扩散,降低细胞内外浓差。本研究结果可用于指导神经球冷冻保存的实验研究,优化保护剂导入程序。

A mathematical model based on M-S equations and the 2-P model was developed to describe the multiple cryoprotectant transport behavior in neurosphere. Profiles of concentration in extracellular and intraeellular volume and concentration difference after cryoprotectant addition were calculated. An analysis of influencing factors such as concentration ratio, neurosphere size and loading procedure was conducted. The results show anti-concentration diffusion in the multicomponent mass transfer process. The change of DMSO in extracellular space is faster than that in the intracellular element and concentration difference increases initially and decreases afterwards. Profiles of concentration of cryoprotectant change greatly with the change of concentration ratio. The size of the neurosphere has a significant impact on cryoprotectant concentration near the center of the neurosphere. The multi-step loading and continuous loading procedures can slow down mass diffusion and reduce the concentration difference. The results are of significance for the optimization of cryoprotectant loading procedures.