Assessment of gelatin-epigallocatechin gallate nanoparticles with hyaluronic acid coating for treating dry eye associated keratopathy in rats

Keratoconjunctivitis sicca (KCS) is a common ocular disease in dogs characterized by inflammation of the cornea and conjunctiva. This study investigates the effectiveness of gelatin-epigallocatechin gallate nanoparticles with hyaluronic acid coating (GEH NPs) and various artificial tears in treating KCS led keratopathy in a rat model. Eighteen female Sprague-Dawley rats, aged 6 to 8 weeks were randomly assigned to 6 groups of 3. All rats except the Sham group underwent unilateral exorbital and infraorbital lacrimal gland excisions to induce KCS. The treatment groups included a KCS group without treatment, a GEH group treated with GEH NPs, and 3 groups receiving different artificial tears. Clinical examinations, including slit-lamp biomicroscopy, optical coherence tomography (OCT), and ocular surface analyser-VET (OSA-VET) were conducted preoperatively at 1 and 2 weeks postoperatively. For treating KCS associated keratopathy, the GEH NPs showed superior outcomes and consistently ranked among the strongest treatment options in most aspects evaluated, including reduced corneal irregularity, improved tear film stability, and lower fluorescein scores, indicating better corneal integrity. Additionally, the GEH group displayed the least inflammatory cell infiltration and maintained a healthier epithelial structure, further underscoring its protective effects. GEH was administered twice daily while other treatment groups were administrated 3 times daily, highlighting its efficacy even with a lower dosing frequency. The artificial tears demonstrated variable benefits on KCS led keratopathy across different evaluations. GEH NPs exhibited excellent protective effects and therapeutic potential on dry eye associated keratopathy based on this study.