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纳米低温保存技术很可能是新一代低温保存技术的发展方向,但未见将纳米颗粒应用于卵母细胞玻璃化保存的报道。本文将不同粒径的羟基磷灰石纳米颗粒添加到冷冻保护剂中,使用Cryotop法对第二次减数分裂中期(MⅡ期)的猪卵母细胞进行玻璃化保存,结果表明纳米颗粒的添加提高了猪MⅡ期的卵母细胞的低温保存存活率,但纳米颗粒的粒径影响不显著。采用超快速测温装置测量低温保护剂的降温速率,并采用差示扫描量热仪(DSC)测量冷冻保护剂的熔融焓,发现纳米颗粒的添加并不能加速溶液的降温速率,而是降低了冷冻过程及复温过程中反玻璃化产生的冰晶量,由于冰晶量减少,从而可能降低了细胞内外冰晶对细胞的机械损伤。
Nano-cryogenic preservation technology is likely to be a new generation of cryogenic preservation technology, but no application of nanoparticles in oocyte vitrification has been reported. In this paper, hydroxyapatite nanoparticles with different particle sizes were added into the cryoprotectant. Cryotop method was used to vitrify the porcine oocytes during the second metaphase (MII stage). The results showed that the addition of nanoparticles Increased the survival rate of porcine MⅡ oocytes at low temperature, but the effect of nanoparticle size was not significant. The ultra-fast temperature measurement device was used to measure the cooling rate of the cryoprotectant. The enthalpy of fusion of the cryoprotectant was measured by differential scanning calorimetry (DSC). It was found that the addition of nanoparticle did not accelerate the solution cooling rate, but decreased The amount of ice crystals produced by de-vitrification during the freezing process and the rewarming process may reduce the mechanical damage to the cells caused by ice crystals inside and outside the cell due to the reduction in the amount of ice crystals.