Enhanced exosomes for fertility protection against chemotherapy-induced ovarian damage

Exosome-based therapies are emerging as promising tools in regenerative medicine and tissue protection. In this study, we engineered exosomes by mimicking paracrine signaling between umbilical cord-derived mesenchymal stem cells (UC-MSCs) and granulosa cells to mitigate chemotherapy-induced ovarian toxicity. Enhanced exosomes were evaluated in vitro, in vivo, and ex vivo using human granulosa cells, cyclophosphamide-treated mice, and cultured ovarian tissues from humans and rats. Enhanced exosomes demonstrated protective effects compared with chemotherapy-only controls. Molecular analyses revealed increased pro-proliferative and anti-apoptotic gene expression and reduced apoptotic markers following treatment. In vivo, enhanced exosome administration was associated with 70% higher primordial follicle counts and a two-fold increase in combined primordial and primary follicles relative to CTX controls. Primary follicle numbers were markedly elevated ( > 20-fold vs CTX). In breeding studies, pup numbers increased from 1 in CTX-treated mice to 7 in enhanced exosome-treated mice in the first mating, and pregnancies were observed in later breeding rounds only in the enhanced group. Enhanced exosomes also modulated ATP-binding cassette transporter expression. In human ovarian tissue ex vivo, treatment resulted in a two-fold increase in AMHR2 expression. These findings support engineered exosomes as a potential platform for oncofertility preservation and mitigation of chemotherapy-associated gonadotoxicity.