Amination-mediated nano eye-drops with enhanced corneal permeability and effective burst release for acute glaucoma treatment

[Display omitted] •A strategy based on nanocapsule amination is proposed for treating acute glaucoma.•Highly aminated-chitosan coatings bestow nanocarrier with a novel functional niche.•Rational biomaterials design enhances corneal permeation and drug bioavailability.•Effective burst release from nanocarriers can alleviate acute ocular hypertension.•Nano eye-drop is a better topical formulation than conventional antiglaucoma drop. The development of topical formulations with advanced functions to overcome the poor and sluggish permeability/bioavailability of traditional eye drops into interior of the eye is significantly important for efficient management of acute intraocular diseases. For the first time, we herein exploit the amination level effects of chitosan coatings for facilitating a fast penetration of ceria nanocapsules (NCs) through the corneal barriers followed by triggering an effective burst release of pilocarpine in a controlled manner. Specifically, high amination level can help to improve the permeability of the ceria NCs through corneal cell layers by ∼ 43 folds while endowing the carriers with the most effective burst release performance. In an experimental rabbit model of acute glaucoma, a single dose topical instillation of pilocarpine-loaded chitosan-coated ceria NCs could effectively reduce the extremely high intraocular pressures to normal, prevent damage of endothelium (precluding ∼ 98.7 % cell death), open the angle closure, and inhibit retinal degeneration (impeding ∼ 98 % of retinal axon loss) at 4 h post-treatment. These findings show a great promise for the development of nano eye-drops for efficient management of acute glaucoma and other acute diseases that need prompt treatments.