Fertility Preservation in Childhood Cancer: Endocrine Activity in Prepubertal Human Testis Xenografts Exposed to a Pubertal Hormone Environment.

Survivors of childhood cancer are at risk for long-term treatment-induced health sequelae, including gonadotoxicity and iatrogenic infertility. At present, for prepubertal boys there are no viable clinical options to preserve future reproductive potential. We investigated the effect of a pubertal induction regimen with gonadotrophins on prepubertal human testis xenograft development.

Testicular tissue cryopreservation is the preferred method to preserve spermatogonial stem cells prior to transplantation.

Research Question: Which cryopreservation method better protects reproductive potential: the cryopreservation of a testicular cell suspension (TCS) or the cryopreservation of testicular tissue (TET)?

Design: Two cryopreservation strategies for spermatogonial stem cells (SSCs) were compared in a mouse model: cryopreservation as TET or as TCS. Evaluated outcomes were number of viable cells after thawing, number and length of donor-derived colonies after spermatogonial stem cell transplantation (SSCT), number of litters, litter size and number of donor-derived pups after mating.

Results: Compared with cryopreserving TCS, cryopreservation of TET resulted in significantly higher numbers of viable cells after thawing (TET: 13.

Does co-transplantation of mesenchymal and spermatogonial stem cells improve reproductive efficiency and safety in mice?

Background: Spermatogonial stem cell transplantation (SSCT) is a promising therapy in restoring the fertility of childhood cancer survivors. However, the low efficiency of SSCT is a significant concern. SSCT could be improved by co-transplanting transforming growth factor beta 1 (TGFβ1)-induced mesenchymal stem cells (MSCs).

What is the best protocol to cryopreserve immature mouse testicular cell suspensions?

Research Question: From a clinical perspective, which parameters grant optimal cryopreservation of mouse testicular cell suspensions?

Design: We studied the effect of different cryopreservation rates, the addition of sugars, different vessels and the addition of an apoptotic inhibitor on the efficiency of testicular cell suspension cryopreservation. After thawing and warming, testicular cell suspensions were transplanted to recipient mice for further functional assay. After selecting the optimal cryopreservation procedure, a second experiment compared the transplantation efficiency between the selected freezing protocol and fresh testicular cell suspensions.

Cryopreservation of Human Testicular Tissue by Isopropyl-Controlled Slow Freezing.

Tissue cryopreservation uses very low temperatures to preserve structurally intact living cells in their natural microenvironment. Cell survival is strongly influenced by the biophysical effects of ice during both the freezing and the subsequent thawing. These effects can be controlled by optimizing the fragment size, type of cryoprotectant, and cooling rate.