Fluorescent nanodiamond and gold nanoparticle hybrid-embedded contact lenses for multifunctional ocular therapy.

Ultraviolet (UV) irradiation, bacterial keratitis, and corneal neovascularization (CNV) are major threats to ocular health and can lead to irreversible vision loss. Effective and multifunctional clinical treatments are therefore urgently needed. Contact lenses represent a promising platform for ocular therapy. However, conventional contact lenses provide limited protection and lack multifunctional therapeutic properties. In this study, chitosan-stabilized gold nanoparticles (Au-CS NPs) were synthesized using a simple approach and further assembled them with negatively charged fluorescent nanodiamonds (FNDs) to form Au-CS@FND nanohybrids. These particles exhibited excellent UV absorption, antibacterial activity, and photothermal conversion efficiency. Incorporation of Au-CS@FNDs into contact lenses (termed A-CLs) endowed the lenses with multifunctional protective properties, including UV shielding and prevention of corneal infection. Moreover, the A-CLs effectively inhibited vascular endothelial cell growth through the photothermal effect of Au nanoparticles, thereby suppressing CNV. To the best of our knowledge, this is the first demonstration of gold and diamond nanoparticles being used as contact lens additives for therapeutic purposes. Our findings suggest that the A-CLs offers a unique and clinically translatable strategy to protect against UV damage, bacterial keratitis, and CNV-associated vision loss.