Evaluation of the Potential of a Fast-Curing Polymer Bioadhesive Hydrogel for Corneal Defect Repair

Corneal defects are a major cause of vision loss and require rapid, biocompatible, and effective sealing methods to restore ocular integrity and prevent infection. Current clinical adhesives, such as cyanoacrylate and fibrin glue, are limited by problems such as poor biocompatibility and inadequate stability. This study presents the design and evaluation of a fast-curable polymer bioadhesive hydrogel, a corneal glue formulated for efficient sealing of corneal defects. Hydrogels were synthesized from natural and synthetic polymers, including polyvinyl alcohol (PVA), sodium alginate (SA), and carboxymethyl cellulose (CMC), optimized for rapid gelation (~45 s), robust adhesion (~15 kPa), and mechanical strength (tensile strength ~0.35 MPa and storage modulus G' indicating strong elastic behavior). Physicochemical and rheological properties, including swelling behavior and optical transparency (>90% transmittance across 400-700 nm), were characterized, including gelation time, swelling behavior, and mechanical strength. In vitro biocompatibility was assessed using human corneal epithelial cells to evaluate cytotoxicity and cell adhesion. Ex vivo studies on human cadaveric corneas with full-thickness defects measured adhesive strength and sealing efficacy through burst pressure (~38 mmHg) and leakage tests, with comparisons to commercial fibrin and cyanoacrylate adhesives. The optimized corneal glue exhibited fast curing, robust adhesion, high water retention with minimal swelling, favorable viscoelastic properties, and excellent cytocompatibility effectively sealing corneal defects in ex vivo models. These results highlight its potential as a promising fast-curable bioadhesive for corneal wound repair and ocular surface restoration.