Stepped vitrification technique for human ovarian tissue cryopreservation.
Ellen Cristina Rivas Leonel1,2, Ariadna Corral3, Ramon Risco3,4
1Pôle de Recherche en Gynécologie, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Avenue Mounier 52, bte B1.52.02, 1200, Brussels, Belgium.
Scientific Reports
|December 29, 2019
Summary
Stepped vitrification (SV) for human ovarian tissue cryopreservation showed follicle degeneration. High dimethyl sulfoxide (DMSO) concentrations caused cell toxicity, indicating the method needs adaptation for successful ovarian tissue preservation.
Area of Science:
- Reproductive Biology
- Cryobiology
- Tissue Engineering
Background:
- Stepped vitrification (SV) aims to improve cryopreservation by reducing ice crystal formation and cryoprotectant toxicity.
- Human ovarian tissue cryopreservation is crucial for fertility preservation.
Purpose of the Study:
- To evaluate the efficacy of stepped vitrification (SV) for human ovarian tissue cryopreservation.
- To investigate the causes of follicle degeneration observed after SV.
Main Methods:
- Human ovarian cortex samples were subjected to a stepped vitrification protocol using an automated freezer.
- Cryoprotectant perfusion was assessed using X-ray computed tomography.
- Ice crystal formation was analyzed by freeze-substitution.
- Cellular toxicity was evaluated using transmission electron microscopy.
Main Results:
- Histological evaluation revealed significant follicle degeneration after 24 hours of in vitro culture post-warming.
- Ultrastructural analysis showed signs of dimethyl sulfoxide (DMSO) toxicity, including mitochondrial damage and chromatin alterations.
- No ice crystal formation was detected, and cryoprotectant perfusion was deemed normal.
Conclusions:
- The stepped vitrification protocol, as applied, failed to preserve human ovarian tissue follicles due to excessive dimethyl sulfoxide (DMSO) toxicity.
- Adaptations to reduce cryoprotectant concentrations are necessary to improve the success of this cryopreservation method for ovarian tissue.
