Bowl-shaped Janus mesoporous silica nanomotors: active drug delivery and oxygen modulation for boosting bacterial keratitis treatment

Bacterial keratitis is a primary cause of corneal blindness, with its clinical treatment hampered by inadequate drug penetration into the deep corneal stroma and the growing emergence of antibiotic resistance. Corneal collagen cross-linking (CXL), a promising non-antibiotic strategy relying on riboflavin (RF) photosensitization and UV-induced stromal stiffening, is limited by poor bioavailability and diminished efficacy in infection-induced hypoxic microenvironments. Herein, we fabricate a self-propelled nanomotor system based on bowl-shaped Janus mesoporous SiO2 nanoparticles via ZIF-8-templated in situ masking, for active ocular drug delivery and spatiotemporal oxygen modulation. The nanomotors possess an open hemispherical architecture with abundant mesopores for efficient RF loading; catalase (CAT) is asymmetrically anchored on their outer surface via regioselective functionalization, forming a Janus structure that enables spatially controlled catalysis and directional propulsion. In antibiotic-resistant lesions, CAT catalyzes endogenous H2O2 to generate O2, driving autonomous nanomotor motion while alleviating hypoxia. This propulsion boosts trans-corneal penetration and stromal drug delivery, and sustained RF release combined with localized oxygenation restores CXL efficacy under hypoxia. This work thus presents a microenvironment-responsive nanoplatform with well-defined structure that integrates active drug delivery and oxygen modulation, overcoming key therapeutic barriers in bacterial keratitis and holding great translational potential for precision ocular nanomedicine.