Ali Mohamed Mohamed Shehata
Women Hospital, Faculty of Medicine, University of Cologne. Kerpener Straße 62, 50937 Cologne, Germany.
Iran J Reprod Med. 2015 Oct;13(10):633-44.
Spermatozoa cryopreservation is used for the management of infertility and some other medical conditions. The routinely applied cryopreservation technique depends on permeating cryoprotectants, whose toxic effects have raised the attention towards permeating cryoprotectants-free vitrification technique.
To compare between the application of slow cryopreservation and vitrification on human spermatozoa.
This was an experimental controlled study involving 33 human semen samples, where each sample was divided into three equal parts; fresh control, conventional slow freezing, and permeating cryoprotectants-free vitrification. Viability and mitochondrial membrane potential (MMP) of control and post-thawing spermatozoa were assessed with the sperm viability kit and the JC-1 kit, respectively, using fluorescence-activated cell sorting analysis.
Significant reduction of the progressive motility, viability and MMP was observed by the procedure of freezing and thawing, while there was not any significant difference between both cryopreservation techniques. Cryopreservation resulted in 48% reduction of the percentage of viable spermatozoa and 54.5% rise in the percentage of dead spermatozoa. In addition, high MMP was reduced by 24% and low MMP was increased by 34.75% in response to freezing and thawing. Progressive motility of spermatozoa was correlated significantly positive with high MMP and significantly negative with low MMP in control as well as post-thawing specimens (r=0.8881/ -0.8412, 0.7461/ -0.7510 and 0.7603/ -0.7839 for control, slow and vitrification respectively, p=0.0001).
Although both cryopreservation techniques have similar results, vitrification is faster, easier and associated with less toxicity and costs. Thus, vitrification is recommended for the clinical application.
精子冷冻保存用于治疗不孕症及其他一些医疗状况。常规应用的冷冻保存技术依赖于渗透性冷冻保护剂，其毒性作用已引发对无渗透性冷冻保护剂玻璃化技术的关注。
比较慢速冷冻保存和玻璃化技术在人类精子上的应用效果。
这是一项实验对照研究，涉及33份人类精液样本，每份样本均分为三个相等部分：新鲜对照、传统慢速冷冻和无渗透性冷冻保护剂玻璃化。分别使用精子活力试剂盒和JC-1试剂盒，通过荧光激活细胞分选分析评估对照及解冻后精子的活力和线粒体膜电位（MMP）。
冷冻和解冻过程导致精子的前向运动能力、活力和MMP显著降低，而两种冷冻保存技术之间无显著差异。冷冻保存导致活精子百分比降低48%，死精子百分比升高54.5%。此外，冷冻和解冻后，高MMP降低了24%，低MMP升高了34.75%。对照样本以及解冻后样本中，精子的前向运动能力与高MMP显著正相关，与低MMP显著负相关（对照、慢速冷冻和玻璃化技术的r值分别为0.8881/-0.8412、0.7461/-0.7510和0.7603/-0.7839，p = 0.0001）。
尽管两种冷冻保存技术结果相似，但玻璃化技术更快、更简便，且毒性和成本更低。因此，推荐玻璃化技术用于临床应用。
