A biomimetic cryoprotectant preserves extracellular vesicles bioactivity for intravenous administration and...

Extracellular vesicles (EVs) have emerged as promising vehicles for drug delivery and disease therapy owing to their intrinsic biocompatibility and capacity to transfer functional biomolecules. However, limitations in current storage technologies, including structural degradation and bioactivity loss during long-term freezing, and the incompatibility of conventional cryoprotectants such as DMSO and glycerol with intravenous administration, pose major barriers to clinical translation. Herein, we developed DDAS, a biomimetic cryoprotectant formulation, rationally designed through generative artificial intelligence (GAI)-assisted prioritization of physiologically relevant candidates from the Human Metabolome Database. DDAS comprises dextran, albumin, and sialic acid, which were selected for their synergistic stabilization and inherent biocompatibility. Compared with standard preservation media, DDAS markedly improved EVs stability during prolonged cryopreservation and repeated freeze-thaw cycles, effectively preserving vesicle morphology, particle concentration, and cargo protein functionality while reducing aggregation and membrane damage. Notably, DDAS exhibited negligible cytotoxicity and excellent biocompatibility, enabling direct intravenous administration without re-isolation or washing. Importantly, stem cell-derived EVs preserved in DDAS fully retained their therapeutic activity in vivo, significantly attenuating inflammation and accelerating wound repair upon systemic administration. Together, this study develops and validates DDAS, a practical, clinically feasible biomimetic cryoprotectant assisted by GAI. DDAS enables the long‑term preservation of EVs with intact functionality and significantly enhances the therapeutic efficacy of stem cell EVs in wound healing, ultimately unlocking their full clinical potential.