M2 macrophage-derived extracellular vesicles ameliorate Benzalkonium Chloride-induced dry eye.

Dry eye disease (DED) is a common ocular condition affecting a significant portion of the global population, yet effective treatment options remain elusive. This study investigates the therapeutic potential of M2 macrophage-derived extracellular vesicles (M2-EVs) in a mouse model of DED. The DED model was established using 0.2% benzalkonium chloride (BAC) eye drops, applied twice daily for a week. Post induction, the mice were categorized into 5 groups: PBS, Sodium Hyaluronate (HA, 0.1%), Fluoromethalone (FM, 0.1%), M0-EVs, and M2-EVs. The efficacy of M2-EVs was assessed through tear production, corneal fluorescein staining and HE staining. RNA sequencing (RNA-seq) was employed to investigate the mechanisms underlying the therapeutic effects of M2-EVs in DED. Notably, the M2-EVs treated group exhibited the highest tear secretion, indicating improved tear film stability and reduced corneal surface damage. Histological analysis revealed better corneal structure organization in the M2-EVs group, suggesting enhanced ocular surface repair and corneal preservation. Furthermore, M2-EVs treatment significantly decreased pro-inflammatory cytokine levels and showed unique enrichment of genes related to retinal development. These findings suggest that M2-EVs could serve as a promising noninvasive therapeutic approach for human DED, targeting ocular surface inflammation.