Preservation of mouse ovarian tissue follicle morphology and ultra-structure after vitrifying in biotechnological protocols

Background: The aim of the present study was to characterize the morphological and ultrastractural of mouse ovarian tissue with different cryoprotectant solution. Objective: Aim of this study, is to demonstrae an improved convetional vitrification method on mouse ovarian tissue using different concentrations of ethylene glycol (EG) and/or dimetyl sulfoxide (DMSO) and EG. Materials and methods: Mouse ovarian tissue dissected and were randomly assigned to three groups: control, conventional vitrification (CV) and toxicity test. Then ovaries were vitrified by 5%, 10% EG or DMSO CV1-CV4, 5%, 10% EG plus DMSO CV5-CV6 and EG plus DMSO in climbing concentrations CV7. The effect of cryoprotectant solutions on ovarian tissue were evaluated by histological examination hematotoxillin & eosin stain, H&E, viability assessment trypan blue stain and ultrastructural analyses transmission electron microscopy, TEM. Results: Ovarian tissue frozen in CV7 solution showed a higher percentage of morphologically normal follicles or viable follicles than other cryoprotectant solutions P < 0.05. Ultrastructural analysis of ovarian tissue showed that less damage was observed in CV7 and it was very similar to the control group. Conclusion: Vitrification of ovarian tissue with optimal cryoprotectant solutions such as EG plus DMSO is the most effective for preserving the structural efficiency of ovarian follicles.