Among the currently available strategies for sperm freezing, vitrification may be considered as the leading alternative to conventional cryopreservation. Nevertheless, a direct comparison of both techniques with respect to the iatrogenic sperm DNA damage has not been performed yet. As such, this study was focused to assess the static and dynamic behavior of human sperm DNA damage following thawing of cryopreserved or vitrified spermatozoa. Semen samples were obtained from fifty donors with a normal spermiogram, and divided into four aliquots. The first aliquot represented the neat sample. In the second aliquot the seminal plasma was discarded, and the resulting sperm pellet was resuspended in PBS. The third fraction was used for slow freezing and the fourth fraction was subjected to vitrification. Each set of samples was incubated at 37 °C for 24 h and sperm DNA damage (SDF) was assessed using the chromatin-dispersion test following 0 h, 2 h, 4 h and 24 h of incubation. When comparing the rate of DNA fragmentation (r-SDF) at 2 h, significant differences were observed between the PBS group, cryopreserved (p .000) or vitrified semen (p .015). Furthermore, the sperm longevity comparison using Kaplan–Meier survival curves revealed significant differences between cryopreservation and vitrification (p .000). Our data suggest that exposure of spermatozoa to low temperatures, independently of the chosen freezing protocol, leads to a higher susceptibility of sperm DNA towards damage. This damage is nevertheless lower following vitrification in comparison to traditional cryopreservation. As vitrification leads to a smaller proportion of spermatozoa with DNA damage, we may recommend its use in reproductive techniques which rely on a longer sperm survival, such as artificial insemination.

在目前可用的精子冷冻策略中，玻璃化冷冻可能被认为是传统冷冻保存的主要替代方案。然而，尚未对两种技术在医源性精子 DNA 损伤方面进行直接比较。因此，本研究的重点是评估冷冻保存或玻璃化精子解冻后人类精子 DNA 损伤的静态和动态行为。精液样本来自五十名精子图正常的捐献者，并分成四份。第一个等分试样代表纯样品。在第二个等分试样中，弃去精浆，将得到的精子沉淀物重新悬浮在 PBS 中。第三部分用于缓慢冷冻，第四部分进行玻璃化。每组样品在 37°C 下孵育 24 小时，并在孵育 0 小时、2 小时、4 小时和 24 小时后使用染色质分散试验评估精子 DNA 损伤（SDF）。当比较 2 小时的 DNA 片段化率 (r-SDF) 时，PBS 组之间观察到显着差异，冷冻保存（p .000) 或玻璃化精液 ( p .015)。此外，使用 Kaplan-Meier 存活曲线的精子寿命比较揭示了冷冻保存和玻璃化冷冻之间的显着差异 ( p < .000)。我们的数据表明，将精子暴露在低温下，与所选的冷冻方案无关，会导致精子 DNA 对损伤的敏感性更高。然而，与传统的冷冻保存相比，玻璃化冷冻后的这种损害较低。由于玻璃化冷冻导致 DNA 损伤的精子比例较小，因此我们可能建议将其用于依赖较长精子存活时间的生殖技术，例如人工授精。