Histologic and ultrastructural evaluation of fresh and frozen-thawed human ovarian xenografts in nude mice

Quality and functionality of human ovarian tissue after cryopreservation using an original slow freezing procedure

“…Preservation of microvessel integrity during the freezing/thawing process is a key factor for successful neovascularization of the ovarian transplant, and indispensable for the survival of ovarian follicles [30,46]. In our study, the histology of the vascular system in thawed tissues appeared well-preserved without any morphological sign of cryodamage.…”

Blastocyst Development After Cryopreservation and Subcutaneous Transplantation of Mouse Ovarian Tissue

“…Primordial follicles are abundant and may be resistant to ischemia, as they normally develop within an avascular epithelium and a relatively hypoxic environment (9). A number of angiogenic factors were expressed in transplanted ovarian tissue (10). In addition, most primordial follicles are present in the periphery and are first to benefit from revascularization.…”

“…Oktay et al also developed human primordial follicles to the antral stage after transplantation under kidney capsule of nude mice (14,15). Both the ovary and renal capsules are rich in angiogenic factors, such as vascular endothelial growth factor (VEGF) and fibroblast growth factor, which further enhance survival and revascularization (1,3,10). But, as noted in the Introduction, grafts under the renal capsule made ovum retrieval difficult, leading us to investigate subcutaneous transplantation as an alternative.…”

Human oocyte and ovarian tissue cryopreservation and its application

“…It appears that the main obstacles to successful restoration of fertility from frozenthawed ovarian cortex are adhesions and the massive ischemic damage to follicles until neovascularization develops [95]. Most follicles which survive cryopreservation undergo ischemic loss during the time required for neovascularization [97].…”