Orozco Cabral Joseph A, Lee Pei-Chih, Wang Shangping, Wang Yizhou, Zhang Yong, Comizzoli Pierre, Elliott Gloria D
Department of Mechanical Engineering and Engineering Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA.
Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC 20008, USA.
Bioengineering (Basel). 2023 Aug 24;10(9):1000. doi: 10.3390/bioengineering10091000.
Although drying techniques are exciting alternatives to cryopreservation, it remains challenging to maintain tightly controlled temperatures and humidity levels during storage of dried products. The objective of this study was to determine if the addition of choline acetate to trehalose solution could enable a wider range of storage conditions for preservation of nuclei from fully grown oocytes, by allowing temporary humidity excursions (>44% relative humidity) that may lead to crystallization of trehalose and loss of DNA integrity. Using domestic cat germinal vesicle oocytes as a model, we characterized the recovery as well as the integrity of samples after microwave-assisted dehydration. Exposure to choline acetate alone did not impair the germinal vesicle's DNA integrity and only had a negative impact on the chromatin configuration. Choline acetate addition enabled us to reach lower moisture contents after 25 min of microwave-assisted drying. Sample recovery after rehydration was also better in the presence of choline acetate. The integrity of the germinal vesicle's DNA was not affected, while the chromatin configuration was impaired by the presence of choline acetate during dehydration. Importantly, choline acetate addition helped to maintain an amorphous state (absence of detrimental crystallization) during excursion from ideal humidity conditions.
尽管干燥技术是冷冻保存的令人兴奋的替代方法，但在干燥产品储存期间维持严格控制的温度和湿度水平仍然具有挑战性。本研究的目的是确定在海藻糖溶液中添加醋酸胆碱是否能够通过允许可能导致海藻糖结晶和DNA完整性丧失的临时湿度波动（相对湿度>44%），为保存完全成熟卵母细胞的细胞核提供更广泛的储存条件。以家猫生发泡卵母细胞为模型，我们对微波辅助脱水后样品的回收率和完整性进行了表征。单独暴露于醋酸胆碱不会损害生发泡的DNA完整性，仅对染色质构型有负面影响。添加醋酸胆碱使我们在微波辅助干燥25分钟后能够达到更低的水分含量。在有醋酸胆碱存在的情况下，复水后的样品回收率也更好。生发泡DNA的完整性不受影响，而脱水过程中醋酸胆碱的存在会损害染色质构型。重要的是，添加醋酸胆碱有助于在偏离理想湿度条件期间维持无定形状态（无有害结晶）。
