Dual-Pronged Strategy on Autoimmune Uveitis by Topical Application of Bioactive Carbon Dots from Natural Herbs

Uveitis is a leading cause of vision loss in the working-age population, yet conventional hormone therapy often comes with numerous side effects. Here, we present a noninvasive topical treatment strategy using HSCDs─a bioactive carbon dot derived from plant-based components─as eye drops for autoimmune uveitis. We developed these carbon dots with strong scavenging capacity against reactive oxygen and nitrogen species (RONS) and the ability to penetrate from the ocular surface into the retina. In an experimental autoimmune uveitis (EAU) mouse model, this treatment demonstrated dual-pronged therapeutic effects by alleviating oxidative stress, inhibiting microglial M1 activation via the Nrf2/HO-1 pathway, and reducing the inflammatory reactivity of retinal vascular endothelial cells, while restoring retinal vascular homeostasis, thereby ameliorating uveitis. Additionally, a biosafety assessment confirmed that HSCDs possess favorable biocompatibility and immunological safety. Collectively, our work establishes these carbon dots as a safe and effective topical nanotherapeutic for autoimmune uveitis.