Retinal Degeneration Response to Graphene Quantum Dots: Disruption of the Blood–Retina Barrier Modulated by Surface Modification-Dependent DNA Methylation

Graphene quantum dots (GQDs) are used in diverse fields from chemistry-related materials to biomedicines, thus causing their substantial release into the environment. Appropriate visual function is crucial for facilitating the decision-making process within the nervous system. Given the direct interaction of eyes with the environment and even nanoparticles, herein, GQDs, sulfonic acid-doped GQDs (S-GQDs), and amino-functionalized GQDs (A-GQDs) were employed to understand the potential optic neurotoxicity disruption mechanism by GQDs. The negatively charged GQDs and S-GQDs disturbed the response to light stimulation and impaired the structure of the retinal nuclear layer of zebrafish larvae, causing vision disorder and retinal degeneration. Albeit with sublethal concentrations, a considerably reduced expression of the retinal vascular sprouting factor