Multifunctional ceria nanozyme with dual anti-fungal/anti-MMP activity for glucocorticoid- associated severe fungal keratitis: A transcriptomics- guided design

Fungal keratitis (FK) poses a significant threat to vision, with a substantial risk of corneal blindness. This risk is markedly amplified by the inappropriate application of glucocorticoids (GCs), yet the underlying pathogenesis remains unclear, and targeted therapeutic strategies are lacking. Through RNA sequencing (RNA-seq), we revealed profound pathological alterations in corneal tissues from FK mice exposed to dexamethasone (DXMS), mainly characterized by robust inflammatory cascades, disrupted collagen turnover, elevated matrix metalloproteinases (MMPs), and excessive oxidative stress. These factors probably contributed to the observed deterioration in DXMS- treated FK mice, evidenced by significantly increased corneal perforation incidence and fungal burden. Guided by these histopathological insights, we designed an integrated therapeutic nanozyme, termed VDCe-NPs. These nanoparticles combined a cerium oxide (CeO 2 ) nanozyme core (providing reactive oxygen species (ROS) scavenging) with anti-fungal agent voriconazole (VRC) and a pan-inhibitor for MMP doxycycline (Doxy). The formed VDCe-NPs exhibited a quasi-spherical morphology with an average diameter of 9.965 ± 1.947 nm, and displayed excellent biocompatibility, potent ROS scavenging, effective anti-fungal potential, and broad-spectrum MMP inhibition. In vivo studies confirmed that VDCe-NPs significantly mitigated DXMS-associated severe FK, with decreased expression of pro-inflammatory cytokines, lowered MMP levels, reduced expression of oxidative stress-related genes and higher expression of antioxidative-related genes. Collectively, these findings not only addressed the key molecular pathological features of GC- associated severe FK, but also established VDCe-NPs as a promising platform for this challenging condition.