Department of Obstetrics and Gynaecology, University Maternal Hospital, Cologne University, Cologne, Germany.
Center of Translational Medicine, Scientific and Technological Bioresource Nucleus (CEMT- BIOREN), Department of Preclinical Science, Faculty of Medicine, University de La Frontera, Temuco, Chile.
Andrology. 2017 Nov;5(6):1055-1063. doi: 10.1111/andr.12414. Epub 2017 Oct 9.
This review describes 120 years history of technology for cryoprotectant-free cryopreservation of human spermatozoa by direct plunging into liquid nitrogen (vitrification). It is presented an explanation why cryoprotectant-free vitrification for some human ejaculates is better than conventional freezing and vitrification with the presence of cryoprotectants. Special attention is given to the extremely high viability of viruses, bacteria and micoplasmas after cryoprotectant-free cryopreservation in culture medium and even in distilled water. This fact increases the potential risk of disease transmission through liquid nitrogen. It is concretized the concept "asepticity" as obvious parameter for any medical assisted reproduction technology which includes the cooling of cells in liquid nitrogen. It is described the role of nonpermeable compounds of mediums for cryoprotectant-free vitrification: carbohydrates, proteins, lipoproteins, antioxidants. This review summarizes concerned data regarding two groups of different current technologies for cryoprotectant-free vitrification of human spermatozoa: with direct contact of spermatozoa with liquid nitrogen as well as with full isolation of these cells from liquid nitrogen (aseptic technologies).
这篇综述描述了 120 年来人类精子无冷冻保护剂直接浸入液氮（玻璃化）冷冻保存技术的发展历程。本文解释了为什么对于某些人类精液样本，无冷冻保护剂的玻璃化冷冻比传统的冷冻保护剂冷冻和玻璃化冷冻效果更好。特别关注的是，在无冷冻保护剂的冷冻保存下，病毒、细菌和支原体在培养基中甚至在蒸馏水中的存活率极高。这一事实增加了通过液氮传播疾病的潜在风险。将“无菌性”作为任何包括细胞在液氮中冷却的辅助生殖技术的明显参数的概念具体化为现实。本文还描述了培养基中非渗透性化合物在无冷冻保护剂玻璃化中的作用：碳水化合物、蛋白质、脂蛋白、抗氧化剂。本综述总结了关于两组不同的人类精子无冷冻保护剂玻璃化技术的相关数据：一种是精子直接与液氮接触，另一种是精子完全与液氮隔离（无菌技术）。
