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.