Advancements in fertility preservation strategies for pediatric male cancer patients: a review of cryopreservation and transplantation of immature testicular tissue

Recently, there has been increasing emphasis on the gonadotoxic effects of cancer therapy in prepubertal boys. As advances in oncology treatments continue to enhance survival rates for prepubertal boys, the need for preserving their functional testicular tissue for future reproduction becomes increasingly vital. Therefore, we explore cutting-edge strategies in fertility preservation, focusing on the cryopreservation and transplantation of immature testicular tissue as a promising avenue. The evolution of cryopreservation techniques, from controlled slow freezing to more recent advancements in vitrification, with an assessment of their strengths and limitations was exhibited. Detailed analysis of cryoprotectants, exposure times, and protocols underscores their impact on immature testicular tissue viability. In transplantation strategy, studies have revealed that the scrotal site may be the preferred location for immature testicular tissue grafting in both autotransplantation and xenotransplantation scenarios. Moreover, the use of biomaterial scaffolds during graft transplantation has shown promise in enhancing graft survival and stimulating spermatogenesis in immature testicular tissue over time. This comprehensive review provides a holistic approach to optimize the preservation strategy of human immature testicular tissue in the future.

Impact of Temperature and Time Interval Prior to Immature Testicular-Tissue Organotypic Culture on Cellular Niche

Cryopreservation of immature-testicular-tissue (ITT) prior to gonadotoxic treatment, while experimental, is the only recommended option for fertility preservation in prepubertal boys. The handling and manipulation of ITT before cryopreservation could influence the functionality of cells during fertility restoration, which this study explored by evaluating cellular niche and quality of mouse ITT subjected to various temperatures and time durations in vitro. ITT from 6-day-old mice were handled at ultraprofound-hypothermic, profound-hypothermic, and mild-warm-ischemic temperatures for varying time periods prior to 14-day organotypic culture. Viability, functionality, synaptonemal complex and chromatin remodeling markers were assessed. Results have shown that cell viability, testosterone level, and in vitro proliferation ability did not change when ITT were held at ultraprofound-hypothermic-temperature up to 24 h, whereas cell viability was significantly reduced (P < 0.01), when held at profound-hypothermic-temperature for 24 h before culture. Further, cell viability and testosterone levels in cultured cells from profound-hypothermic group were comparable to corresponding ultraprofound-hypothermic group but with moderate reduction in postmeiotic cells (P < 0.01). In conclusion, holding ITT at ultraprofound-hypothermic-temperature is most suitable for organotypic culture, whereas short-term exposure at profound-hypothermic-temperature may compromise postmeiotic germ cell yield post in vitro culture. This data, albeit in mouse model, will have immense value in human prepubertal fertility restoration research.

Fertility Preservation in Pubertal and Pre-Pubertal Boys with Cancer

Children diagnosed with cancer continue to have improved survival due to advances in effective treatment options. Increased attention is therefore now focused on quality of life issues once they are cured. Fertility preservation is of paramount concern since gonadotoxic treatments, especially radiation and chemotherapy, often impair future fertility. The importance of family counseling and having an informed discussion about the potential for treatment to impair fertility and the options available for fertility preservation is crucial. However, fertility preservation in prepubertal boys is challenging, but not impossible. Experimental methods are being investigated including cryopreservation of immature testicular tissue, xenografting, and in vitro germ cell maturation. Despite the success and relative ease of sperm banking, barriers exist and affect the number of patients offered treatment. Education and awareness of the possibilities can overcome these barriers. In this way we will continue to preserve young patients' future fertility and quality of life.

Biopolymer gels as a basis of cryoprotective medium for testicular tissue of rats

Cryopreservation of testis tissue is a promising approach to save fertility in prepubertal boys under going gonadotoxic cancer therapies. The using biopolymers as a basis of cryoprotective medium can be effective for the optimization of cryopreservation protocols of immature testicular tissue. The research purpose was to determine morphological parameters and metabolic activity of seminiferous tubules of immature rat testes under exposure to cryoprotective solution (DMSO) based on collagen or fibrin gels (CG or FG) as one of the first stages of developing the cryopreservation protocol. It was found that 30-min exposure of tissue samples to CG and FG with 0.6 M DMSO did not impair the spermatogenic epithelium and metabolic activity of the cells (MTT test and total lactate dehydrogenase activity). The use of FG at the time of exposure of 45 min did not lead to significant changes in the metabolic activity in contrast to other groups. The findings could be used to substantiate and develop the effective techniques for cryopreservation of immature seminiferous tubules.