Umbilical Cord Mesenchymal Stem Cells and Their Extracellular Vesicles Attenuate Cryopreservation-induced Ovarian Injury via the Suppression of Ferroptosis in an In Vitro Culture System

Ovarian tissue cryopreservation is a vital fertility preservation technique. However, cryopreservation-induced injury significantly limits its efficacy in frozen-thawed ovarian tissue transplantation. This study investigated the therapeutic potential of umbilical cord mesenchymal stem cells (UC-MSCs) and their derived extracellular vesicles (MSC-EVs) for repairing cryopreservation-induced ovarian injury via ferroptosis in an in vitro culture system. RNA sequencing revealed ferroptosis as a key regulatory pathway in cryopreserved ovarian tissue. This was characterized by downregulation of GPX4, upregulation of ACSL4, elevated Fe 2+ levels, glutathione depletion, and enhanced lipid peroxidation. UC-MSCs and MSC-EVs effectively suppressed ferroptosis, restored GPX4 expression, and reduced lipid peroxidation, mirroring the effects of the ferroptosis inhibitor ferrostatin-1. In an in vitro culture system, UC-MSCs and MSC-EVs enhanced follicular survival and angiogenesis, while reducing apoptosis. Transplantation experiments demonstrated improved graft vascularization, hormone secretion, and oocyte retrieval in treated groups. Notably, MSC-EVs demonstrated comparable efficacy to UC-MSCs, suggesting their potential as a nanoscale therapeutic strategy. These findings elucidate ferroptosis as a critical mechanism in cryopreservation-induced injury and highlight UC-MSCs and MSC-EVs as promising therapeutic agents for improving ovarian tissue cryopreservation outcomes. This study presents the therapeutic potential of umbilical cord mesenchymal stem cells (UC-MSCs) and their derived extracellular vesicles (MSC-EVs) for repairing cryopreservation-induced ovarian injury via ferroptosis in an in vitro culture system. By suppressing ferroptosis, MSC-EVs emerge as effective nanoscale and cell-free therapeutic candidates, significantly enhancing ovarian tissue cryopreservation outcomes. These findings provide critical mechanistic insights and establish a novel nanobiotechnological strategy to improve ovarian tissue transplantation, thereby bridging the interface between regenerative medicine and advanced biomaterials.