Investigation of silicone hydrogel contact lenses functionalized with hollow silica nanoparticles for drug loading

Abstract

In recent years, hydrogel contact lenses used as ocular drug-delivery platforms have received extensive attention in the medical field. However, they suffer from limited drug-loading capacity and rapid release profiles, typically achieving complete release within 1–2 hours, which makes it difficult to maintain long-term therapeutic efficacy. Additionally, conventional hydrogel contact lenses exhibit insufficient oxygen permeability, and long-term wear of drug-loaded lenses may lead to corneal hypoxia and increase the risk of ocular surface infections. In this study, a novel silicone hydrogel corneal contact lens loaded with hollow silica nanoparticles (HSN-SCL) was prepared using an immersion method. Levofloxacin was used as a model drug to evaluate the drug-loading capacity and release behavior of the HSN-SCL. The results showed that the drug-loading capacity of HSN-SCL reached 253.2 µg per lens with a nanoparticles content of 2 wt%. Meanwhile, the lenses exhibited an oxygen permeability of 98 Barrer while maintaining stable water content and mechanical properties. Therapeutically meaningful drug delivery was achieved under in vitro conditions. Cytotoxicity tests indicated no obvious adverse effects. These results suggest that HSN-SCL lenses can enhance drug loading while maintaining essential lens properties, providing guidance for nanoparticle-functionalized hydrogel design.