Reproductive Medicine Center, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.
Reprod Biol Endocrinol. 2010 May 11;8:42. doi: 10.1186/1477-7827-8-42.
Cryopreservation of isolated follicles may be a potential option to restore fertility in young women with cancer, because it can prevent the risks of cancer transmission. Several freezing protocols are available, including slow-rate freezing, open-pulled straws vitrification (OPS) and solid-surface vitrification (SSV, a new freezing technique). The purpose of our study was to investigate the effects of these freezing procedures on viability, ultrastructure and developmental capacity of isolated rat follicles.
Isolated follicles from female Sprague-Dawley rats were randomly assigned to SSV, OPS and slow-rate freezing groups for cryopreservation. Follicle viability assessment and ultrastructural examination were performed after thawing. In order to study the developmental capacity of thawed follicles, we performed in vitro culture with a three-dimensional (3D) system by alginate hydrogels.
Our results showed that the totally viable rate of follicles vitrified by SSV (64.76%) was slightly higher than that of the OPS group (62.38%) and significantly higher than that of the slow-rate freezing group (52.65%; P < 0.05). The ultrastructural examination revealed that morphological alterations were relatively low in the SSV group compared to the OPS and slow-rate freezing groups. After in vitro culture within a 3D system using alginate hydrogels, we found the highest increase (28.90 +/- 2.21 microm) in follicle diameter in follicles from the SSV group. The estradiol level in the SSV group was significantly higher than those in the OPS and slow-rate freezing groups at the end of a 72-hr culture period (P < 0.05).
Our results suggest that the SSV method is an appropriate and convenient method for cryopreservation of isolated rat follicles compared with the conventional slow-rate freezing method and the OPS method.
冷冻保存分离的卵泡可能是一种潜在的选择，以恢复年轻女性癌症患者的生育能力，因为它可以防止癌症传播的风险。有几种冷冻方案可供选择，包括慢速冷冻、开放式吸管玻璃化（OPS）和固-液玻璃化（SSV，一种新的冷冻技术）。我们的研究目的是研究这些冷冻程序对分离的大鼠卵泡活力、超微结构和发育能力的影响。
从雌性 Sprague-Dawley 大鼠中分离的卵泡被随机分配到 SSV、OPS 和慢速冷冻组进行冷冻保存。解冻后进行卵泡活力评估和超微结构检查。为了研究解冻卵泡的发育能力，我们使用藻酸盐水凝胶进行了三维（3D）系统的体外培养。
我们的结果表明，SSV 冷冻的卵泡总存活率（64.76%）略高于 OPS 组（62.38%），显著高于慢速冷冻组（52.65%；P<0.05）。超微结构检查显示，SSV 组的形态改变与 OPS 和慢速冷冻组相比相对较低。在使用藻酸盐水凝胶的 3D 系统中进行体外培养后，我们发现 SSV 组的卵泡直径增加最高（28.90 +/- 2.21 微米）。在 72 小时培养期结束时，SSV 组的雌二醇水平明显高于 OPS 和慢速冷冻组（P<0.05）。
与传统的慢速冷冻法和 OPS 法相比，我们的结果表明 SSV 方法是一种合适且方便的分离大鼠卵泡冷冻保存方法。
