Topical hyaluronic acid (HA) formulations have been extensively employed for managing various ocular diseases, but their therapeutic efficacy is severely compromised by rapid precorneal clearance due to a dense, negatively charged sialic acid-rich glycocalyx. To address this, we report a corneal surface engineering strategy that involves the metabolic incorporation of bioorthogonal azide groups onto the corneal epithelium. This covalent "docking" layer enables site-specific, Click chemistry-mediated immobilization of anionic HA, thereby significantly enhancing its ocular surface retention in vitro and in vivo. First, an alkyne-bearing molecule (DBCO) was labelled with a fluorescent probe (Cy5) to produce DBCO-Cy5. Sequential incubation of human corneal epithelial cells (HCECs) with an unnatural azide-bearing sugar (AAM) and DBCO-Cy5 enhanced the Cy5 retention by more than 10-fold. Then, HA was covalently labelled with DBCO at different conjugation ratios (HA-DBCO), and these conjugates showed negligible cytotoxicity. HA-DBCO binding to AAM-pretreated cells was time- and concentration-dependent; a higher degree of substitution substantially improved the reaction efficiency. Meanwhile, the covalent conjugation of HA to the cell surface did not affect HCEC proliferation but enhanced cell migration. The proof-of-concept was also validated in a mouse model of dry eye disease. AAM was ocularly delivered via a cationic liposome, resulting in the predominant deposition of azide in the corneal epithelium of mice. Subsequent dosing of HA-DBCO induced the in vivo bioorthogonal reaction that enhanced HA retention (up to 6 h) by 2.5-fold compared to the control without AAM pretreatment. The prolonged corneal retention enhanced the therapeutic efficacy at a reduced dosing frequency. This approach offers a clinically translatable strategy to improve the efficacy of topical HA-based therapies for ocular diseases.
Enhanced corneal retention of hyaluronic acid via a metabolic glycoengineering-based in vivo bioorthogonal reaction.
发布日期:2026/10/27 13:43:27

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