Penetrative Ionic Organic Molecular Cage Nanozyme for the Targeted Treatment of Keratomycosis.

Abstract

Keratomycosis, caused by pathogenic fungi, is an intractable blinding eye disease. Corneal penetration is an essential requirement for conventional antifungal medications to address keratomycosis. Due to the distinctive anatomical and physiological structure of the cornea, the therapeutic efficacy is hampered by the inadequate penetration capacity. Despite the emergence of diverse antifungal drug delivery systems and advanced antifungal nanomaterials, it has remained challenging to achieve corneal penetration over the past decade. This study fabricates a penetrative ionic organic molecular cage-based nanozyme (OMCzyme) for treating keratomycosis. The synthesis of OMCzyme involved two steps. Initially, the ionic OMC is synthesized by a [2+3] cycloimination reaction of triformylphloroglucinol and 2,3-diaminopropionic acid. Subsequently, OMCzyme is fabricated by coordination of Fe2⁺ with carboxyl anions and phenolic hydroxyls in the organic cage, and further deposition of silver nanoparticles on the surface of OMC-Fe complex. The as-prepared OMCzyme demonstrates excellent water dispersion, peroxidase-like activity, in vitro and in vivo biocompatibility, and corneal penetration. Notably, the nanozyme displays targeted antifungal activity, effectively combating Fusarium solani with negligible cytotoxicity toward human corneal epithelial cells. The hybrid mimic is further demonstrated to be effective in treating keratomycosis in mice, indicating the potential of OMCzyme for curing fungal infectious diseases.