Intraocular-microenvironment responsive fluorescent hydrogels in rhegmatogenous retinal detachment repair

Rhegmatogenous retinal detachment (RRD) is a severe eye condition that can threaten vision without proper treatment. The primary treatment for RRD is vitrectomy, however, the postoperative requirement for a prone position, coupled with unsatisfactory retinal reattachment rates, presents a significant clinical challenge. Recent advancements in technology and material engineering have led to the development of specific biomaterials serving as retinal patches that can seal retinal breaks. Whereas, existing materials still face limitations including the need for specialized implantation instruments and complex surgical operations for certain materials, inadequate conformability to the eyeball due to relatively high material rigidity that impairs sealing performance, and poor biocompatibility. To overcome these difficulties, herein we introduce a novel fluorescent hydrogel composed of 4-arm-PEG-Mal and 4-arm-PEG-SH as a retinal sealant. This innovative material undergoes rapid gelation in response to the weakly alkaline intraocular environment following injury, enabling effective sealing of retinal breaks and the surrounding area. Furthermore, the hydrogel's inherent fluorescent property provides enhanced intraoperative visibility. Evaluated in a rabbit model of retinal detachment, the hydrogel demonstrated efficient therapeutic treatment in promoting RRD repair, while offering significant visual and surgical advantages. In conclusion, the retinal break-sealing hydrogel developed in this work presents a promising new strategy for the treatment of RRD, with considerable potential for clinical translation. • Fluorescence of the hydrogels in the ultraviolet band: The hydrogels can be excited by fluorescence at wavelengths less than 400 nm in the ultraviolet band, and remains transparent under natural light. Thus, it can be excited for fluorescence when the hydrogels need to be observed and remain transparent during the patient's normal life. • Response of the hydrogels in intraocular-microenvironment: In vitro experiments have shown that the hydrogels precursor solution can quickly gelatinize when contact with the intraocular environment, and seal the retina breaks. Thus, vitrectomy can be avoided and complications can be reduced. • Effectiveness of using the hydrogels to seal retinal breaks and treat rhegmatogenous retinal detachment: In the rhegmatogenous retinal detachment model of rabbits, this material effectively closed the retinal breaks and promoted the reattaching of retinal detachment.