High molecular weight hyper-branched PCL-based thermogelling vitreous endotamponades

Area of Science:

• Ophthalmology
• Polymer Science
• Biomaterials

Background:

• Current vitreous endotamponades have limitations including elevated intraocular pressure, vision loss, cataracts, and required removal surgery.
• Next-generation vitreous endotamponades are being developed, with in-situ gelling supramolecular hydrogels showing promise.

Purpose of the Study:

• To develop and evaluate novel hyper-branched amphiphilic copolymers as transparent, biodegradable vitreous endotamponades.
• To assess the efficacy and safety of these thermogels in a rabbit eye model.

Main Methods:

• Synthesis of hyper-branched amphiphilic copolymers via polyaddition of polyethylene glycol, polypropylene glycol, poly(ε-caprolactone)-diol, and glycerol with hexamethylene diisocyanate.
• Injection of thermogel sols into rabbit eyes, observing spontaneous gelation at physiological temperatures.
• Evaluation of biocompatibility, retinal function, inflammation, and clearance mechanisms.

Main Results:

• Hyper-branched thermogels demonstrated effective vitreous tamponade function with excellent biocompatibility.
• Optimal hyper-branching maintained retinal function with minimal atrophy and inflammation.
• The thermogel was cleared naturally via hydrogel erosion, negating the need for surgical removal.

Conclusions:

• Hyper-branched thermogels represent a novel and effective vitreous endotamponade, overcoming limitations of current standards.
• These materials offer improved biocompatibility and biodegradability for intraocular applications.
• The findings expand polymer architecture possibilities for in-vivo therapeutic use beyond linear constructs.