L-proline(2.00 mol/L)---新一代抗凍劑

可用於VS中，取代部分DMSO, EG
減少其對胚胎或卵毒性

(15% DMSO and 15% EG without L-proline)--->(7.5%DMSO+10%EG+2mg/L L-proline)
oocyte survival rate 89%--->93%

http://www.cmj.org/article.asp?issn=0366-6999;year=2016;volume=129;issue=16;spage=1963;epage=1968;aulast=Zhang

Chin Med J (Engl). 2016 20th Aug;129(16):1963-1968. doi: 10.4103/0366-6999.187846.

Cryobiological Characteristics of L-proline in Mammalian Oocyte Cryopreservation.

Zhang L1, Xue X2, Yan J1, Yan LY3, Jin XH1, Zhu XH1, He ZZ2, Liu J4, Li R3, Qiao J3.

Author information

Abstract

BACKGROUND:

L-proline is a natural, nontoxic cryoprotectant that helps cells and tissues to tolerate freezing in a variety of plants and animals. The use of L-proline in mammalian oocyte cryopreservation is rare. In this study, we explored the cryobiological characteristics of L-proline and evaluated its protective effect in mouse oocyte cryopreservation.

METHODS:

The freezing property of L-proline was detected by Raman spectroscopy and osmometer. Mature oocytes obtained from 8-week-old B6D2F1 mice were vitrified in a solution consisting various concentration of L-proline with a reduced proportion of dimethyl sulfoxide (DMSO) and ethylene glycol (EG), comparing with the control group (15% DMSO and 15% EG without L-proline). The survival rate, 5-methylcytosine (5-mC) expression, fertilization rate, two-cell rate, and blastocyst rate in vitro were assessed by immunofluorescence and in vitro fertilization. Data were analyzed by Chi-square test.

RESULTS:

L-proline can penetrate the oocyte membrane within 1 min. The osmotic pressure of 2.00 mol/L L-proline mixture is similar to that of the control group. The survival rate of the postthawed oocyte in 2.00 mol/L L-proline combining 7.5% DMSO and 10% EG is significantly higher than that of the control group. There is no difference of 5-mC expression between the L-proline combination groups and control. The fertilization rate, two-cell rate, and blastocyst rate in vitro from oocyte vitrified in 2.00 mol/L L-proline combining 7.5% DMSO and 10% EG solution are similar to that of control.

CONCLUSIONS:

It indicated that an appropriate concentration of L-proline can improve the cryopreservation efficiency of mouse oocytes with low concentrations of DMSO and EG, which may be applicable to human oocyte vitrification.