Gelatin–epigallocatechin gallate nanoparticles with hyaluronic acid decoration as eye drops can treat rabbit dry-eye syndrome effectively via inflammatory relief

Gelatin–epigallocatechin gallate nanoparticles with hyaluronic acid decoration as eye drops can treat rabbit dry-eye syndrome effectively via inflammatory relief Hsin-Yi Huang,1,2,* Ming-Chen Wang,2,* Zhi-Yu Chen,1 Wen-Ying Chiu,1 Ko-Hua Chen,3,4 I-Chan Lin,4,5 Wei-Chung Vivian Yang,6 Chi-Chang Wu,7 Ching-Li Tseng1,8,9 1Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan; 2Department of Biomedical Engineering, Chung Yuan Christian University, Taoyuan City, Taiwan; 3Department of Ophthalmology, Taipei Veterans General Hospital, Taipei City, Taiwan; 4Department of Ophthalmology, School of Medicine, College of Medicine, Taipei Medical University, Taipei City, Taiwan; 5Department of Ophthalmology, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan; 6PhD Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei City, Taiwan; 7Department of Electronic Engineering, Feng Chia University, Taichung City, Taiwan; 8International PhD Program in Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei City, Taiwan; 9International PhD Program in Cell Therapy and Regenerative Medicine, College of Medicine, Taipei Medical University, Taipei City, Taiwan *These authors contributed equally to this work Introduction: Dry-eye syndrome (DES) is a general eye disease. Eye drops are the common ophthalmological medication. However, the ocular barrier makes it difficult to attain high drug bioavailability. Nanomedicine is a promising alternative treatment for ocular diseases and may increase drug content in the affected eye. Methods: To explore this potential, we constructed nanoparticles (NPs) containing an anti-inflammatory agent for DES treatment. The NPs were made of gelatin–epigallocatechin gallate (EGCG) with surface decoration by hyaluronic acid (HA) and designated “GEH”. The particle size, surface charge, and morphology were evaluated. The in vitro biocompatibility and anti-inflammation effect of nanoparticles were assayed via culturing with human corneal epithelium cells (HCECs) and in vivo therapeutic effect was examined in a DES rabbit’s model. Results: The synthesized GEH NPs had a diameter of approximately 250 nm and were positively charged. A coculture experiment revealed that 20 µg/mL GEH was not cytotoxic to HCECs and that an EGCG concentration of 0.2 µg/mL downregulated the gene expression of IL1B and IL6 in inflamed HCECs. Large amounts of GEH NPs accumulated in the cytoplasm of HCECs and the ocular surfaces of rats and rabbits, indicating the advantage of GEH NPs for ocular delivery of medication. Twice-daily topical treatment with GEH NPs was performed in a rabbit model of DES. The ocular surface of GEH-treated rabbits displayed normal corneal architecture with no notable changes in inflammatory cytokine levels in the cornea lysate. The treatment improved associated clinical signs, such as tear secretion, and fluorescein staining recovered. Conclusion: We successfully produced GEH NPs with high affinity for HCECs and animal eyes. The treatment can be delivered as eye drops, which retain the drug on the ocular surface for a longer time. Ocular inflammation was effectively inhibited in DES rabbits. Therefore, GEH NPs are potentially valuable as a new therapeutic agent delivered in eye drops for treating DES. Keywords: gelatin nanoparticles, epigallocatechin gallate, EGCG, hyaluronic acid, HA, dry-eye syndrome, DES, anti-inflammation