Wound dressing gel with resisted bacterial penetration and enhanced re-epithelization for corneal epithelial-stromal regeneration

Corneal injury-induced inflammation may result in permanent vision loss. In situ forming adhesive hydrogels offer a promising tissue substitute for repair of partial-thickness corneal wounds, but the uncertainty of biodegradation rate potentially fails to form new tissues in vivo. To overcome this problem, a methacrylated collagen (ColMA) hydrogel is newly developed as a wound dressing to repair partial-thickness corneal defects using a two-stage approach. Such a hydrogel can maintain the viability and adhesion of human corneal epithelial cells (HCECs) as well as promoting their migration in vitro. During surgery, we initially photopolymerized ColMA hydrogel to form a in situ coating at defects. The hydrogel is further designed to be dislodged off after implantation and thus avoid the potential risks from the uncontrollable gel biodegradation. In both rabbit and pig corneal defect models, this collagen hydrogel not only serves as a physical barrier to prevent bacterial penetration and corneal wound dehydration, but also produces nanogranules to highly promote re-epithelization, thereby contributing to the decrease of scar formation and improvement of corneal epithelial-stromal regeneration via reducing myofibroblast activation. This study presents a useful platform system that can be adapted and extended towards the repair of diverse tissues or organs through the addition of bioactive molecules, encouraging the ColMA hydrogel wound dressing to be translated into advanced regenerative therapies.