Experimental study on the vitrification and xenotransplantation of human ovarian tissue

Abstract

Background: Cryopreservation 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. Objective: In this study, we evaluated that serum 17β-oestradiol (E2) may be used as an indicator of vitrified ovarian tissue. Methods: Immunodeficient 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. Results: Serum 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. Conclusion: In vivo serum hormone E2 released by cortical biopsies can be used as a functional marker for xenotransplanted vitrified-warmed human ovarian tissue reserve.

Keywords

• Vitrification-warmed
• Ovarian tissue
• 17β-oestradiol
• Xenotransplantation