Introduction: Due to remarkable advances in cancer treatments, we are witnessing a growing population of long-term survivors of childhood malignancies. However, fertility in adult life may be severely impaired by gonadotoxic therapies. The infertility problem among this population is unique, and fertility preservation is a goal not yet achieved. Since prepubertal boys cannot produce spermatozoa, banking of testicular tissue prior to gonadotoxic treatment is considered one of the most promising methods in order to restore future fertility for this population. The objective of this study was to compare cryopreservation efficacy of human testicular tissue by two methods: Uncontrolled Slow Freeze and Controlled Slow Freeze, in order to evaluate cell recovery and viability.
Methods: Human testicular tissues were cryopreserved using controlled and uncontrolled slow-freezing. The frozen tissues were thawed, fixed in 4% PFA, and embedded in paraffin. Six micron sections were stained with H&E, immunohistochemical analysis using antibodies against OCT4 and subjected to histological evaluation. Fresh testicular tissue was used as a control.
Results: Histological analysis demonstrated no significant differences in tissue architecture, structural integrity and cellular morphology between fresh and cryopreserved fragments.
Conclusions: The results of this study demonstrate preserved tissue architecture, structural integrity and cellular morphology of the seminiferous tubules with normal spermatogenesis after testicular tissue cryopreservation. These results confirmed the feasibility of both controlled and uncontrolled slow-freezing cryopreservation methods for testicular tissue cryopreservation and significantly promote the potential future utilization of cryopreserved testicular tissue in fertility restoration for pre-pubertal boys undergoing gonadotoxic cancer treatments.
