In situ forming collagen-PEG hydrogel as a matrix therapy for corneal defects: 2 month in vivo response

Abstract

Purpose : Corneal injuries and subsequent scarring collectively represent a major global human health challenge, affecting millions of people worldwide. We have previously shown that in situ-forming PEG-collagen hydrogels supported epithelial wound closure by 1 week after treatment. Here we aim to evaluate the longer-term benefits of the hydrogel on corneal epithelial layer maturation and stromal scarring, 2 months after treatment.

Methods : Lamellar keratectomies were performed in rabbit corneas followed application of the in situ forming collagen-PEG hydrogel followed by bandage contact lens and partial tarsorraphy placement which were both removed on day 7. The healing and curvature of the treated cornea was monitored by OCT and photography, along with corneal thickness and intraocular pressure (IOP). Two months after the injury, the corneas were fixed for immunohistochemical analysis.

Results : Multi-layered epithelialization with normal morphology and cytokeratin 3 expression was observed at 2 months. Alpha smooth muscle actin expressed was reduced compared to injured, untreated corneas. The hydrogels were partially observed in the central corneal suggesting degradation and near-complete stromal remodeling. Corneal nerves were observed through beta-tubulin expression in the area of the stroma where the gel was placed. Corneal thickness and IOP were measured to be within normal limits by post-op month 1 and after.

Conclusions : The in situ-forming collagen-PEG hydrogel supports normal epithelial wound healing and stromal remodeling return to baseline corneal thickness by two months.

This is a 2021 ARVO Annual Meeting abstract.