Fabrication of nanozyme thixotropic anionic hydrogel for treating fungal keratitis by Dectin-1/p38 pathway

Fungal keratitis (FK) is a major cause of corneal blindness, particularly in China, where treatment is often limited by systemic side effects and antifungal drug resistance. We propose a nanozyme (carbon nanotube (CNT))-based anionic hydrogel coating (NHC) loaded with itraconazole (IZ) (NTH@CNT/IZ) as a treatment for FK to overcome these challenges. This formulation was designed to enhance ocular drug delivery, improve antifungal efficacy, and reduce inflammation. In vitro assays against Aspergillus fumigatus demonstrated potent antifungal activity, including significant reductions in colony-forming units and biofilm formation at 50 µg/mL. Cell viability tests using ARPE-19 cells revealed high biocompatibility, with no observed morphological alterations or apoptosis, despite increased ROS and DNA proliferative activity. Importantly, NTH@CNT/IZ markedly downregulated inflammatory mediators-Dectin-1, IL-1β, and TNF-α-and inhibited phosphorylation of p38 MAPK, indicating suppression of the Dectin-1/p38 MAPK signaling pathway. In vivo results further confirmed its therapeutic potential, showing reduced corneal fungal burden and inflammation, along with effective penetration through the corneal epithelium, overcoming mucosal and fungal barriers. Together, these findings highlight NTH@CNT/IZ as a promising localized treatment strategy for fungal keratitis, offering targeted antifungal action and immune modulation to improve clinical outcomes and preserve ocular integrity. KEY POINTS: Nanozyme hydrogel for ocular health In vitro antifungal efficacy.