Antioxidants increase blastocyst cryosurvival and viability post-vitrification

Area of Science:

• Reproductive biology and developmental science.
• Cryobiology and assisted reproductive technologies (ART).

Background:

• Vitrification is a cryopreservation technique used in ART.
• Oxidative stress during vitrification can impair embryo development and viability.
• Antioxidants may mitigate cryo-induced damage.

Purpose of the Study:

• To investigate the effect of a specific antioxidant combination (A3: acetyl-L-carnitine, N-acetyl-L-cysteine, α-lipoic acid) on mouse blastocyst development and viability after vitrification and warming.
• To determine if antioxidants in vitrification/warming solutions improve post-thaw embryo quality and developmental potential.

Main Methods:

• Mouse blastocysts (F1) were vitrified and warmed with or without the A3 antioxidant combination in the solutions.
• Post-warming, embryos were cultured, and their cell number, allocation, apoptosis, and histone acetylation were assessed.
• Viability was evaluated using in vitro outgrowth models and in vivo uterine transfers.

Main Results:

• Vitrification without antioxidants significantly reduced blastocyst cell numbers and increased apoptosis.
• The A3 antioxidant combination in vitrification/warming solutions significantly increased inner cell mass and total cell numbers, and improved outgrowth area.
• Embryo transfer of A3-treated blastocysts resulted in improved fetal weight, crown rump length, and limb development, correlating with higher viability.

Conclusions:

• Vitrification and warming negatively impact mouse blastocyst histone acetylation and viability.
• The A3 antioxidant combination effectively alleviates cryopreservation-induced damage, enhancing embryo developmental potential and viability.
• Antioxidants must be present during the vitrification process to protect against oxidative stress and improve outcomes in ART.