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.

Stimulus‐Responsive Hydrogels as Drug Delivery Systems for Inflammation Targeted Therapy

“…Several kinds of photosensitive agents, such as diazobenzene (Azo) and spiropyrane, could change the hydrogel network from hydropho- Reproduced with permission. [248] Copyright 2022, John Wiley & Sons. b) UV-triggered HA-based hydrogel to accelerate wound healing.…”

“…Chen and co‐workers developed a in situ forming hydrogel to serve as a novel absorbable lacrimal plug for the alleviation of dry eye, which is a common chronic disease with complex pathogenesis. [ 248 ] They used methacrylate‐modified silk fibroin (SFMA) as the hydrogel matrix and, to achieve the noninvasive monitor, NIR‐triggered indocyanine green (ICG) was prepared as fluorescence tracer NPs (FTN). The SFMA/FTN hydrogel solution was injected into the canaliculi, exposed to the blue light, the liquid quickly transformed into hydrogel and formed a shape‐match plug to block the lacrimal passage.…”

“…Light-responsive hydrogels. a) Visible-induced hydrogel to alleviate dry eye and could be monitored by NIR due to the presence of ICG.Reproduced with permission [248]. Copyright 2022, John Wiley & Sons.…”

Recent Advances in Hydrogels for the Diagnosis and Treatment of Dry Eye Disease

“…Mild dry eye can often be relieved through the use of lubricating eye drops. However, for patients with moderate and severe dry eye, a lacrimal plug is used to block lacrimal canaliculi to prolong lacrimal retention for long-term treatment [ 144 ]. Xu et al [ 145 ] prepared a PVA/KGM/SA composite (PKS-2) hydrogel from konjac glucomannan (KGM), sodium alginate (SA), and PVA by calcium hydroxide crosslinking, which can be used as a potential material for lacrimal duct obstruction.…”

Regenerative cerium oxide nanozymes alleviate oxidative stress for efficient dry eye disease treatment

“…), the ROS level will grow sharply, and the balance between ROS and antioxidant enzymes will be disrupted [ 4 , 18 ]. Subsequently, pathological changes will appear in the cornea, conjunctiva and lacrimal gland, followed by tear film hyperosmolarity and decreased stability, inducing the occurrence of DED [ 19 , 20 ]. Therefore, developing new therapies that possess anti-oxidative and anti-inflammatory capabilities by attenuating excessive ROS on the ocular surface is highly desirable in DED treatment [ 21 ].…”