Epigallocatechin gallate cooperated with hydrogel encapsulation enables high-performance cryopreservation of mouse ovaries

Cryopreservation and transplantation of ovarian tissue have emerged as promising techniques for preserving fertility in prepubescent girls and cancer patients who cannot postpone treatment. However, this technology faces several challenges. In particular, conventional methods often fail to mitigate serious oxidative stress issues and cytotoxic damage caused by cryoprotectants, which can affect transplant outcomes. To overcome this bottleneck, a new strategy was proposed here, a new cryoprotectant formula (12% ethylene glycol+12% propylene glycol +0.5 M sucrose+75 μM epigallocatechin gallate) was developed and combined with hydrogel encapsulation to optimize ovarian cryopreservation. This approach avoids the utilization of DMSO and reduces the concentration of penetrating cryoprotectant by 20%. The findings indicate that this strategy significantly reduced oxidative damage, fibrosis degree, and tissue apoptosis during cryopreservation and enhanced the quality of cryopreserved mouse ovaries. Furthermore, in vivo and in vitro tests assessing ovarian and oocyte quality further validate the safety and reliability of this research protocol. This study is anticipated to provide a new strategy for female fertility preservation through ovarian cryopreservation.