为获得较优的脐带血干细胞(cord blood cells,CBCs)冷冻保存效果,引入非晶态物理学玻璃化方法,进行冻存、解冻的理论和实验分析.模拟计算以Karlsson模型为基础,结果显示,近似实现脐带血干细胞玻璃化的降温速率、复温速率应分别不低于400℃/min和500℃/min;在此速率下采用两步法冷冻脐带血干细胞,冻存前后对样品细胞计数,浓度分别为1.0、1.5和1.75 mol/L的3种二甲基亚砜(Dimethyl Sulphoxide,DMSO)保护剂溶液,其快速冷冻脐带血的存活率对应为(86.8±2.5)%、(90.6±5.4)%和(87.5±3.4)%,即不低于80%的脐带血干细胞保持外壁光滑、形态完整,保存后具有较高的存活率.与平衡慢速冷冻法获得的60%存活率相比,降温速率、复温速率应分别不低于400℃/min和500℃/min的快速冷冻将大大提高脐带血干细胞的存活率.
Vitrification technique of amorphous phys cedure for cord blood cells (CBCs). The Karlsson's ics was introduced to model was used to c develope a ompute the cleation and crystal growth during the cooling and rewarming processes. Experimen cryopreservation procell dehydration, nutal study of umbilical cord blood (UCB) cryopreservation was pursued with two-step method. Theoretical analysis showed that survival rates not less than 80% were achieved when the cooling rate and rewarming rate were not lower than 400 ℃/min and 500 ℃/min, respectively. Experimental results showed that after quick-freezing cryopreservation, the survival rates of the three samples, whose DMSO concentration were 1.0, 1.5 and 1.75 mol/L respectively, were (86.8±2.5) %, (90.6±5.4)% and (87.5±3.4)% correspondingly. Compared with 60% survival rate obtained by slow-freezing croypreservation methods, the quick-freezing method remarkably increased the survival rate of CBCs.