Bioactive peptides-incorporated photo-crosslinking hydrogel for suture-free repair of corneal injuries

The development of new biomaterials for suture-free repair of corneal stromal injuries holds promise, especially given the shortage of donor corneas and the limitations of current tissue adhesives. Here, we developed a biocompatible hydrogel via ultrafast in situ photo-crosslinking between di-o-nitrobenzyl-modified Arg-Gly-Asp (RGD) peptide and carboxymethyl chitosan. This hydrogel exhibits shape adaptability, high transparency, and robust bioadhesion, making it suitable for suture-free corneal repair. In vitro experiments confirm that the hydrogel promotes corneal epithelial cell migration. In a rabbit model of penetrating corneal injury, the hydrogel achieves rapid sealing within 60 s while maintaining anterior chamber integrity. In a deep corneal defect model, it effectively seals the stromal wound and supports corneal regeneration, enhancing epithelial barrier restoration with upregulated expression of zonula occludens-1 (ZO-1) and cytokeratin 3 (CK3). Moreover, incorporation of the neuropeptide CGRP into the hydrogel reduces stromal fibrosis, as indicated by decreased expression of α-smooth muscle actin (α-SMA) and vimentin. This bioactive peptides-integrated photo-crosslinking hydrogel represents a promising alternative for suture-free repair of severe corneal injuries and offers a new, effective strategy for clinical corneal wound management.