# Ultrasmall Copper-Based Nanozyme Eye Drops for Effective Antioxidative Therapy of Ocular Surface Diseases

## TL;DR

Researchers developed copper-based nanozyme eye drops that effectively reduce oxidative stress and inflammation in corneal diseases.

## Contribution

A new eco-friendly synthesis of ultrasmall Cu5.4O nanoparticles for antioxidant and anti-inflammatory eye drops is introduced.

## Key findings

- Cu5.4O nanoparticles effectively scavenge hydrogen peroxide and reduce intracellular ROS in corneal cells.
- Cu5.4O NP eye drops are biocompatible and provide protection against oxidative corneal damage in mice.
- The nanozyme formulation promotes epithelial regeneration and reduces inflammation in oxidative damage models.

## Abstract

Developing an effective strategy to mitigate the excessive
production
of reactive oxygen species (ROS) caused by diverse factors is crucial
for preventing ocular surface diseases. However, due to the inherent
characteristics of ocular barriers, the therapeutic efficacy of conventional
eye drops remains unsatisfactory. Copper-based nanozymes are known
for their enzyme-mimetic ROS scavenging abilities. In this study,
we report a simple, ecofriendly, one-step synthesis of ultrasmall
copper Cu5.4O nanoparticles (NPs) as antioxidant and anti-inflammatory
nanozymes in eye drop formulations. The Cu5.4O NPs showed
strong hydrogen peroxide (H2O2) scavenging ability
and reduced intracellular ROS in corneal cells in vitro. In vitro hemolysis studies and in vivo assessments of ocular biocompatibility confirmed that Cu5.4O NP eye drops are safe for application as nanomedicines in ophthalmic
formulations. Moreover, in the H2O2-induced
corneal oxidative damage model in mice, Cu5.4O NP eye drops
effectively scavenged ROS and reduced inflammation, thereby providing
protection against oxidative damage and facilitating epithelial regeneration.
Collectively, the capabilities of Cu5.4O NP-based eye drops
offer valuable insights into developing new treatment strategies for
ROS-mediated corneal diseases and support the use of nanomaterials
in clinical applications.