Cryosurvival and spermatogenesis after allografting prepubertal mouse tissue: comparison of two cryopreservation protocols.

Although childhood cancer treatments are yielding higher survival rates, sterility remains one of the major side effects. For prepubertal boys there are currently no options to preserve fertility. Testicular tissue banking together with subsequent grafting may become a possible strategy in the future. In the present study, we compared two cryopreservation protocols using prepubertal murine testicular tissue. Fresh and cryopreserved testicular tissue was grafted subcutaneously on the back of immune-deficient mice for at least 3 months. Prepubertal murine tissue recovered well after cryopreservation with both ethylene glycol (EG) and dimethylsulfoxide (DMSO). While in fresh murine allografts, spermatozoa were observed in 23% of the tubules; in both the DMSO and the EG groups, 32% of the seminiferous tubules contained spermatozoa. However, with DMSO the structure of the seminiferous tubules was better preserved.