ZIF-L as a protective coating of native extracellular vesicles enabling long-term storage at aqueous ambient condition

• Strategy stabilizes native extracellular vesicles (EVs) without cryogenic storage. • ZIF-L coating enables long-term aqueous storage of EVs with intact bioactivity. • EDTA-triggered ZIF-L decoating preserves EVs’ structural and functional integrity. • ZIF-L-protected apoptotic EVs retain osteogenic potential after 30-day storage. Native apoptotic extracellular vesicles (apoEVs) exhibit versatile regulatory functions and represent a promising new therapeutic class. However, their fragile lipid bilayer membrane presents significant challenges for long-term storage. In this study, the possibility of metal–organic frameworks as protective coating for apoEVs has been investigated comprehensively. Briefly, the apoEVs from RAW264.7 cells have been isolated as the model EVs to perform the leaf-like zeolitic imidazolate framework (ZIF-L) coating through one-pot synthesis. By several characterizations, it has been proven that the apoEVs were totally coated by ZIF-L nanorod clusters within 2 h via biomimetic mineralization. Meanwhile, the ZIF-L shells could be completely removed by ethylenediaminetetraacetic acid (EDTA) in 90 min without affecting the apoEVs properties including morphology, size, zeta potential and surface biomarker. In addition, the apoEVs encapsulated with ZIF-L showed no significant difference in bioactivity compared to freshly isolated apoEVs after storage in aqueous ambient condition for 30 days, including protein profiles, in vivo distribution, in vitro uptake by recipient cells and regulation of their osteogenesis. Overall, these findings validate ZIF-L encapsulation as a robust preservation method that maintains apoEVs bioactivity across storage durations, providing a cue for addressing critical challenges in therapeutic vesicle stabilization.