Rapid desiccation and on-disc rehydration of extracellular vesicles for non-cryogenic preservation

Storage options for extracellular vesicles (EVs) remain limited, constraining their clinical and research applications. Conventional low-temperature freezing (-80 °C), although the established standard, requires substantial resources and presents logistical challenges. Here, we report an AridEx (Ambient Retention in Disc of Extracellular vesicles) approach for efficient room-temperature storage and recovery of EVs. AridEx leverages isothermal vitrification principles to preserve EVs, utilizing an electrospun trehalose-dextranol matrix as a xeroprotectant. The xeroprotectant matrix, combined with highly gas-permeable membranes, was integrated into a centrifugal microfluidic device, enabling the rapid desiccation of EV samples under mild vacuum conditions. The dried samples were stored directly on the disc at ambient temperature and subsequently recovered on demand via on-disc rehydration and EV isolation. AridEx achieved preservation efficacy equivalent to that at -80 °C, preserving EV particle counts and surface proteins during ambient storage periods of at least 6 months. In a pilot clinical study, AridEx-preserved plasma retained consistent biomarker signals for accurate cancer diagnosis. This compact and cartridge-based platform is manufacturable and could offer a sustainable alternative to low-temperature sample storage for diagnostic applications.