Antioxidants and Antifreeze Proteins in Cryopreservation/Vitrification

With the demand for cryopreservation of gametes, embryos, and ovarian tissue ever increasing, it is important to maintain research into how such processes can be further optimized. Here, we consider how antioxidants (AOX) and antifreeze proteins (AFP) can play a role in human ART. Specific antioxidants have the capacity to significantly reduce the oxidative stress associated with both culture and cryopreservation and have been demonstrated to confer benefit to both vitrification and slow freezing of gametes and embryos. By their nature, antifreeze proteins reduce the capacity of ice crystals to form and have also been shown to improve outcomes associated with the cryopreservation of gametes, embryos, and ovarian tissue. Consequently, the inclusion of AOX and AFP in cryopreservation procedures holds great promise clinically. Here, we consider which AOX and AFP have been used to date and discuss the significance of utilizing more than individual AOX to maximize their functions. Further, the combined effects of AOX and AFP on reproductive cells and tissues have not yet been investigated and could therefore represent a new frontier in cryobiology for assisted conception.