Experimental Study on the Vitrification and Xenotransplantation of Human Ovarian Tissue

BackgroundCryopreservation of ovarian tissue is a promising method for preserving fertility. Transmission electron microscopy (TEM) is an evaluation system for cryo-injury during the cooling and warming process which is very laborious and needs to be optimized.ObjectiveIn this study, we evaluated that serum 17β-oestradiol (E2) may be used as an indicator of vitrified ovarian tissue.MethodsImmunodeficient nude mice were used as hosts for xenografting of vitrified-warmed human ovarian tissues. A total of 54 mice were divided into two group: vitrified ovarian xenotransplant (VOX) group (n ​= ​45) and non-transplant control group (n ​= ​9). The transplanted mice were grouped into vitrified/warmed grafted-4 weeks (VOX-4w, n ​= ​15), vitrified/warmed grafted-6weeks (VOX-6w n ​= ​15) and vitrified/warmed grafted-12 weeks (VOX-12w n ​= ​15) according to the time after transplantation.The viable and functional recovery of grafted ovarian tissue was assessed by light microscopy, transmission electron microscopy, and hormone (E2) assays.ResultsSerum E2 concentration was significantly higher in VOX-6w (group (21.07 ​pg/ml) than that of VOX-12w group (15.59 ​pg/ml). VOX-12w group showed a lower value (12.61 ​pg/ml) for E2 concentration. The trend for E2 concentration was consistent with the morphological identification of the grafts.ConclusionIn vivo serum hormone E2 released by cortical biopsies can be used as a functional marker for xenotransplanted vitrified-warmed human ovarian tissue reserve.