Anchoring polyethylene glycol to the ocular surface by phenylboronic acid functionalization: Implications for fabrication of long-acting artificial tears

Artificial tears, generally formulated with lubricant polymers, constitute the mainstay of therapy for dry eye. However, the short ocular retention of currently available artificial tears necessitated frequent dosing and resulted in poor patient compliance. Binding lubricant polymers to ocular sialic acid was recently recognized as a feasible approach to fabricate long-acting artificial tears. Based on the well-established complexation between phenylboronic acid (PBA) and sialic acid, we hypothesize PBA functionalities can be harnessed to anchor lubricant polymers to ocular surface. Herein, we took polyethylene glycol (PEG) as a representative lubricant polymer and demonstrated PBA functionalized PEG can bind the ocular surface in vitro with human corneal and conjunctival epithelial cells and ex vivo with rabbit cornea and conjunctiva. Meanwhile, the PBA functionalized PEG showed good cytocompatibility. Given the wide applicability of PBA functionalization, our study provides a promising avenue for developing long-acting artificial tears in the future.