Overcoming the Stromal Barrier of the Cornea with a Peptide Conjugate Nano-Assembly to Combat Fungal Keratitis.

Fungal hyphae deeply invade the cornea in fungal keratitis. The corneal stroma hinders the infiltration of antifungal drugs and reduces their bioavailability. Here, this work reports a peptide conjugate nano-assembly that permeates the stroma and kills the pathogen without irritating the ocular cornea. The hydrophilic surface of the nano-assembly ensures deep permeation into the stroma. When encountering a fungal hyphal cell, the nano-assembly disassembles and exposes the α-helical peptide to destroy the fungal membrane, thus inactivating the pathogen. In a rabbit model of fungal keratitis, the nano-assembly exhibits a better therapeutic effect than commercially available natamycin ophthalmic suspension. Peptide conjugates with a nano-assembled structure and assembly-disassembly behavior could serve as the foundation of a new therapy for fungal keratitis.