Barbosa Bianca Barreto, Evangelista Inara Tayná Alves, Soares Airton Renan Bastos, Leão Danuza Leite, Pereira Ricardo José Garcia, Domingues Sheyla Farhayldes Souza
Laboratório de Biotecnologia e Medicina de Animais da Amazônia, Universidade Federal do Pará, Castanhal, PA, Brasil.
Programa de Pós-graduação em Saúde e Produção Animal na Amazônia, Universidade Federal Rural da Amazônia, Belém, PA, Brasil.
Anim Reprod. 2023 May 22;20(2):e20220096. doi: 10.1590/1984-3143-AR2022-0096. eCollection 2023.
Sperm cryopreservation is an important tool for genetic diversity management programs and the conservation of endangered breeds and species. The most widely used method of sperm conservation is slow freezing, however, during the process, sperm cells suffer from cryoinjury, which reduces their viability and fertility rates. One of the alternatives to slow freezing is vitrification, that consist on rapid freezing, in which viable cells undergo glass-like solidification. This technology requires large concentrations of permeable cryoprotectants (P- CPA's) which increase the viscosity of the medium to prevent intracellular ice formation during cooling and warming, obtaining successful results in vitrification of oocytes and embryos. Unfortunately, this technology failed when applied to vitrification of sperm due to its higher sensitivity to increasing concentrations of P-CPAs. Alternatively, a technique termed 'kinetic sperm vitrification' has been used and consists in a technique of permeant cryoprotectant-free cryopreservation by direct plunging of a sperm suspension into liquid nitrogen. Some of the advantages of kinetic vitrification are the speed of execution and no rate-controlled equipment required. This technique has been used successfully and with better results for motility in human (50-70% motility recovery), dog (42%), fish (82%) and donkey (21.7%). However, more studies are required to improve sperm viability after devitrification, especially when it comes to motility recovery. The objective of this review is to present the principles of kinetic vitrification, the main findings in the literature, and the perspectives for the utilization of this technique as a cryopreservation method.
精子冷冻保存是遗传多样性管理计划以及濒危品种和物种保护的一项重要工具。最广泛使用的精子保存方法是慢速冷冻，然而，在此过程中，精子细胞会遭受冷冻损伤，这会降低它们的活力和受精率。慢速冷冻的替代方法之一是玻璃化冷冻，它包括快速冷冻，在此过程中活细胞会经历类似玻璃的固化。这项技术需要高浓度的渗透性冷冻保护剂（P-CPA），这会增加培养基的粘度，以防止在冷却和升温过程中细胞内形成冰晶，在卵母细胞和胚胎的玻璃化冷冻中取得了成功。不幸的是，由于精子对P-CPA浓度增加的敏感性更高，这项技术应用于精子玻璃化冷冻时失败了。另外，一种称为“动态精子玻璃化冷冻”的技术已被使用，它是一种通过将精子悬液直接投入液氮进行无渗透性冷冻保护剂冷冻保存的技术。动态玻璃化冷冻的一些优点是执行速度快且不需要速率控制设备。这项技术已成功应用，在人类（活力恢复率为50-70%）、狗（42%）、鱼（82%）和驴（21.7%）的精子活力方面取得了更好的效果。然而，需要更多研究来提高解冻后精子的活力，尤其是在活力恢复方面。这篇综述的目的是介绍动态玻璃化冷冻的原理、文献中的主要发现以及将该技术用作冷冻保存方法的前景。
