不同浓度冷冻保护剂乙二醇在人扩张囊胚玻璃化冷冻中的应用

目的研究不同浓度冷冻保护剂乙二醇(ethlene glycol,EG)在人扩张囊胚玻璃化冷冻中的应用。方法不同浓度EG 15%,30%,40%,联合15%二甲基亚砜(dimethylsulphoxide,DMSO),0.5 mol/L蔗糖(sucrose),采用两步法,利用改制半麦管为冷冻载体,玻璃化冷冻人扩张囊胚。比较解冻后囊胚存活率,扩张率及孵出率;并比较微吸管吹吸、辅助孵化针刺破胞膜辅助脱水及未辅助脱水对冷冻扩张囊胚的影响。结果由1原核(pronucleus, PN)发育而来的扩张囊胚玻璃化冷冻解冻后囊胚存活率15%EG组明显高于30%及40%EG组(P<0.05)。由2PN 发育成的扩张囊胚玻璃化冷冻解冻后囊胚孵出率15%EG组明显高于30%及40%EG组(P<0.05)。在冷冻过程中给予人工辅助脱水组解冻后囊胚孵出率明显高于未辅助脱水组(P<0.05)。微吸管吹吸组与辅助孵化针刺破胞膜辅助脱水组囊胚孵出率差异无显著性(P>0.05)。结论15%EG为人扩张囊胚玻璃化冷冻中有效和合适浓度。玻璃化冷冻中给予人工辅助脱水,能提高解冻后囊胚的发育潜能。

Vitrification of human expanded blastocyst using three different concentration of ethylene glycol

Objective The aim of the study is to analyse three different concentration of ethylene glycol(EG)in vitrification of human expanded blastocysts. Methods With a two - step protocol, human expanded blastcysts was vitrified in vitrification solution consisting of three different concentration of ethylene glycol (15%,30%,40%), 15% dimethylsulphoxide (DMSO) and 0.5 mol/L sucrose with the Henri - Straw carrier. After thawing of expanded blastocysts, the survival rates, re - expanded rates and hatching rates were compared. Another aim of study is to evaluate the difference between two artificially shrunk methods using pipetting, or the use of a glass micro - needle and compare with control group. Results The survival rates after thawing of human expanded blastocyst origin from 1PN in the 15% EG group was significantly higher than that in the 30%, 40% EG group, and the same results was found in 2PN group. The hatching rates in 15% EG group was significantly higher compared with 30% and 40% EG group, respectively(P<0.05) . The hatching rates in artificially shringkage group was significantly higher than control group(P<0.05), but no significant difference was found between two artificially shrunk methods(P>0.05) .Conclusion The result suggest that the effective, appropriate concentration of EG is 15% in vitrification of human expanded blastocysts. After artificially shringkage, the potential of development of human expanded blastocysts will be improved.