卵子冷冻

Oocyte cryopreservation, also known as egg freezing, is now a reality in the specialty of reproductive endocrinology and infertility. It has opened many new and exciting avenues of treatment options for assisting the infertile population but also has new applications for women wishing to preserve their fertility for medical indications or personal reasons.

卵母细胞冻存，也称卵子冷冻，现在已经成为生殖内分泌学和不育这一专业领域的现实。它已经成为帮助不孕不育人口的一个很多新的和令人兴奋的治疗选择，而且在妇女希望因医药适应症或个人原因而保持其生育能力方面有新的应用。

The Egg Freezing Process

卵子冷冻流程

Progress in egg freezing remained stagnant because early trials of egg freezing used suboptimal freeze/thaw protocols, which did not address the structural differences between oocytes and embryos. The intent of most freezing protocols is to achieve simultaneous exchange of intracellular water with protective solutions in a limited amount of time, under special lab conditions, without causing injury to the target tissue. Since the human egg is the largest cell in the body and is composed mostly of water, the formation of ice during freezing can disrupt the egg’s internal microscopic contents and its outer membrane. Therefore cryoprotectants, which act as “antifreeze solution" are used to dehydrate the water and replace it with the protective solution to reduce internal ice formation.

卵子冷冻进展维持停滞状态因为早期的卵子冷冻试验使用次优的冷冻/解冻协议，它没有说明卵母细胞和胚胎的结构性差异。多数冷冻卵子的协议的目的是在有限的时间、在特殊的实验室条件下，没有引起目标组织伤害的情形下，用保护的方法达到同步交换细胞内水分的目的。既然人类的卵子是体内最大的细胞，而且大部分是由水组成的，卵子冷冻过程中冰的形成囊破坏卵子内部的极小物质及其外部的膜。因此冷冻保护剂作为“反解冻解决方案”用来脱水，并减少内部的冰的形成。
It is a known fact that osmosis causes an exchange of the egg’s inner cell water with cryoprotectant fluids by diffusion across the egg membrane. To facilitate the transference of the fluids, a delicate balance of the solution’s concentration, the time exposure to the solutions and the temperature of the culture system are needed to achieve optimal levels of water replacement. However, the dilemma is that these cryoprotectants tend to be cytotoxic and as such they may damage the egg if exposure is too long at “high” temperatures (4 to 37 degrees Celcius). So the science of egg freezing (cryobiology) is all about compromise: how to remove water as quickly as possible, without damaging the egg.

已知的事实是渗透作用引起卵子内部细胞的水与扩散过卵子膜而与冷冻保护剂中的液体进行交换。为了便利液体的转移，精致的方法集中平衡、时间与培育系统的温度要用来达到最优的水替换水平。然而，困境是这些冷冻保护剂倾向于成为细胞毒素，因此如果暴露在高温（摄氏4°-37°）下时间过长，就会破坏卵子。因此卵子冷冻科学（低温生物学）是由以下因素构成的：如何尽快地在不破坏卵子的情况下去掉水。