In Situ Forming Hydrogel as a Tracer and Degradable Lacrimal Plug for Dry Eye Treatment

Abstract Lacrimal plug is an effective and widely therapeutic strategy to treat dry eye. However, almost all commercialized plugs are fixed in a certain design and associated with many complications, such as spontaneous plug extrusion, epiphora, and granuloma and cannot be traced in the long‐term. Herein, a simple in situ forming hydrogel is developed as a tracer and degradable lacrimal plug to achieve the best match with the irregular lacrimal passages. In this strategy, methacrylate‐modified silk fibroin (SFMA) is served as a network, and a self‐assembled indocyanine green fluorescence tracer nanoparticle (FTN) is embedded as an indicator to develop the hydrogel plug using visible photo‐crosslinking. This SFMA/FTN hydrogel plug has excellent biocompatibility and biodegradability, which can be noninvasively monitored by near‐infrared light. In vivo tests based on dry eye rabbits show that the SFMA/FTN hydrogel plug can completely block the lacrimal passages and greatly improve the various clinical indicators of dry eye. These results demonstrate that the SFMA/FTN hydrogel is suitable as an injectable and degradable lacrimal plug with a long‐term tracking function. The work offers a new approach to the development of absorbable plugs for the treatment of dry eye.