School of Veterinary Medicine, Kitasato University, Aomori, 034-8628, Japan.
Kyoto R&D Laboratory, Mitsubishi Paper Mills Limited, Kyoto, 617-8666, Japan.
Cryobiology. 2019 Jun;88:9-14. doi: 10.1016/j.cryobiol.2019.04.008. Epub 2019 Apr 26.
Several closed vitrification devices that avoid contact with liquid nitrogen have been reported. Recently, based on the Kitasato Vitrification System (KVS), we developed the Closed-KVS, which is a closed vitrification device. The KVS is an open vitrification device that can absorb excess vitrification solution. In this study, we performed two experiments to evaluate the efficacy of the Closed-KVS as a vitrification device for the cryopreservation of mouse embryos at the blastocyst and two-cell stage. In the first experiment, the blastocysts were vitrified using either the Closed-KVS or the KVS (control device). The survival, re-expansion, and hatching rates were not significantly different between embryos vitrified using the Closed-KVS and those vitrified using the KVS. In the second experiment, we evaluated the embryonic development of the two-cell stage embryos vitrified using the Closed-KVS. There were no significant differences in the survival, blastocyst formation, or hatching rates between vitrified or non-vitrified embryos. Additionally, we evaluated the cooling and warming rates of these devices using a numerical simulation method. The cooling rates of the Closed-KVS were similar regardless of whether the outer cap was pre-cooled and were lower than those of the KVS. However, the warming rates of the Closed-KVS (irrespective of cap pre-cooling) were the same as those of the KVS (612,000 °C/min). In summary, the Closed-KVS is a novel closed vitrification device for the cryopreservation of mouse embryos at the blastocyst and two-cell stage.
已有几种避免与液氮接触的封闭玻璃化设备被报道。最近，我们基于 Kitasato 玻璃化系统（KVS）开发了封闭 KVS，这是一种封闭的玻璃化设备。KVS 是一种开放式玻璃化设备，可以吸收多余的玻璃化溶液。在这项研究中，我们进行了两项实验，以评估封闭 KVS 作为玻璃化设备用于冷冻保存囊胚和两细胞期小鼠胚胎的效果。在第一个实验中，使用封闭 KVS 或 KVS（对照设备）对囊胚进行玻璃化处理。使用封闭 KVS 玻璃化处理的胚胎与使用 KVS 玻璃化处理的胚胎的存活率、再扩张率和孵化率没有显著差异。在第二个实验中，我们评估了使用封闭 KVS 玻璃化处理的两细胞期胚胎的胚胎发育情况。玻璃化或未玻璃化胚胎的存活率、囊胚形成率或孵化率没有显著差异。此外，我们使用数值模拟方法评估了这些设备的冷却和升温速率。封闭 KVS 的冷却速率与外盖是否预冷无关，且均低于 KVS。然而，封闭 KVS（无论帽预冷）的升温速率与 KVS 相同（612,000°C/min）。综上所述，封闭 KVS 是一种用于冷冻保存囊胚和两细胞期小鼠胚胎的新型封闭玻璃化设备。
