Department of Experimental Medicine, University Laboratory of Seminology - Sperm Bank, University of Rome "La Sapienza", Rome, Italy,
Adv Exp Med Biol. 2014;791:137-50. doi: 10.1007/978-1-4614-7783-9_9.
Cryopreservation is a technique that can keep sperm alive indefinitely, enabling the conservation of male fertility. It involves the cooling of semen samples and their storage at -196°C in liquid nitrogen. At this temperature all metabolic processes are arrested. Sperm cryopreservation is of fundamental importance for patients undergoing medical or surgical treatments that could induce sterility, such as cancer patients about to undergo genotoxic chemotherapy or radiotherapy, as it offers these patients not only the hope of future fertility but also psychological support in dealing with the various stages of the treatment protocols.Despite its importance for assisted reproduction technology (ART) and its success in terms of babies born, this procedure can cause cell damage and impaired sperm function. Various studies have evaluated the impact of cryopreservation on chromatin structure, albeit with contradictory results. Some, but not all, authors found significant sperm DNA damage after cryopreservation. However, studies attempting to explain the mechanisms involved in the aetiology of cryopreservation-induced DNA damage are still limited. Some reported an increase in sperm with activated caspases after cryopreservation, while others found an increase in the percentage of oxidative DNA damage. There is still little - and contradictory - information on the mechanism of the generation of DNA fragmentation after cryopreservation. More studies are needed to establish the true importance of such damage, especially to improve the results of ART.
冷冻保存是一种可以使精子无限期存活的技术，能够保存男性生育能力。它涉及精液样本的冷却和在-196°C的液氮中储存。在这个温度下，所有的代谢过程都停止了。精子冷冻保存对于接受可能导致不育的医学或手术治疗的患者至关重要，例如即将接受基因毒性化疗或放疗的癌症患者，因为它不仅为这些患者提供了未来生育的希望，而且在处理治疗方案的各个阶段时提供了心理支持。
尽管它对辅助生殖技术（ART）很重要，并且在出生婴儿方面取得了成功，但该程序会导致细胞损伤和精子功能受损。尽管结果存在矛盾，但已有多项研究评估了冷冻保存对染色质结构的影响。一些但不是全部作者发现冷冻保存后精子 DNA 损伤显著。然而，试图解释冷冻保存引起的 DNA 损伤发病机制的研究仍然有限。一些报道称冷冻保存后激活的半胱天冬酶的精子增加，而另一些则发现氧化 DNA 损伤的百分比增加。关于冷冻保存后 DNA 碎片化生成的机制，信息仍然很少，而且相互矛盾。需要更多的研究来确定这种损伤的真正重要性，特别是为了提高 ART 的结果。
