A lacrimal duct drug delivery system based on photo-induced hydrogel for dry eye and allergic conjunctivitis therapy

To design an ocular drug delivery system is challenging due to the limited space of the ocular surface and high sensitivity of the cornea. Here, we developed a lacrimal duct drug delivery system, which was non-invasive and could cause no foreign body sensation. Based on hydrogels, our drug-loaded lacrimal plugs had ideal and adjustable properties of mechanical characteristics, swelling ratio and degradation rates. They also showed better biocompatibility and the feasibility of loading various drugs to treat different ocular diseases, compared to the commonly-used plug products. Our drug-loaded lacrimal plugs exhibited sustained and stable drug releasing profiles both in vitro and in vivo for up to three months. To test the therapeutic effect, FK506 loaded plugs and cyclosporine A loaded plugs were used to treat the rat allergic conjunctivitis model and rabbit dry eye model, respectively, which both demonstrated satisfactory long-term efficacy. This study illustrated a lacrimal plug drug delivery system with the potential application in the long-term treatments of a variety of ocular surface diseases.