Potential to modulate corneal epithelial repair via nitric oxide-releasing glycosaminoglycans

Bioactive wound therapies that protect injured tissue, promote regeneration, and prevent infection would represent a promising alternative to traditional passive treatments. In this study, nitric oxide (NO)-releasing glycosaminoglycans (GAGs) were synthesized and evaluated for their therapeutic potential in corneal wound healing. Low and high molecular weight hyaluronic acid (HA) and chondroitin sulfate (CS) derivatives of different sulfation patterns were synthesized and characterized with respect to NO release, antibacterial activity, cytotoxicity, and effects on human corneal epithelial cell proliferation and migration. A three-dimensional corneal tissue scratch closure model was subsequently used to assess in vitro barrier restoration. A derivative consisting of CS with prolonged NO release and low molecular weight HA with intermediate NO-release kinetics were identified as the most promising materials. The HA derivative enhanced epithelial migration even during later timepoints of the migration assays. A carboxymethylcellulose (CMC) gel formulation containing the HA derivative further promoted cell migration. In corneal tissue models, treatment with both the free and CMC-formulated NO-releasing HA enhanced restoration. Barrier recovery, as measured by transepithelial electrical resistance, confirmed restoration of tissue integrity post-wounding, concomitant with a cytokine milieu associated with pro-wound healing. Overall, NO-releasing, low molecular weight HA in a CMC gel formulation represents a promising bioactive strategy for promoting corneal wound repair.