CM11-integrated gelatin-amniotic membrane contact lens promotes corneal regeneration in rabbits

Persistent corneal epithelial defects (PEDs) and microbial keratitis are significant causes of vision loss, often requiring prolonged treatment. Current therapeutic approaches, primarily topical eye drops, suffer from low drug bioavailability and poor patient adherence, limiting their efficacy. This study addresses these challenges by developing a novel therapeutic contact lens that combines a biocompatible hydrogel with the antimicrobial peptide CM11 to provide sustained drug delivery and promote corneal healing. This approach aims to improve drug residence time and therapeutic outcomes for complex corneal pathologies.

Researchers fabricated three hydrogel scaffolds: gelatin (G), gelatin-amniotic membrane (G-AM), and G-AM-P (gelatin-amniotic membrane with CM11 peptide). These were characterized for optical clarity, porosity, hydrophilicity, elastic modulus, and peptide release dynamics. Antibacterial performance was assessed against Staphylococcus aureus, and cytocompatibility was evaluated using human corneal epithelial cells. In vivo efficacy and safety of G-AM-P were then tested in a rabbit model, utilizing slit-lamp examination, anterior segment optical coherence tomography (AS-OCT), and histopathological analysis to monitor ocular tolerance and healing.

The G-AM-P contact lens demonstrated acceptable optical clarity, significant porosity of ~94%, moderate hydrophilicity (contact angle ≈70°), and an elastic modulus of ~0.55 MPa. Peptide release from G-AM-P was biphasic, characterized by an initial rapid phase followed by a sustained plateau for up to 72 hours. In antibacterial assays, G-AM-P effectively inhibited Staphylococcus aureus with a 15 mm zone of inhibition. Furthermore, the scaffold showed no cytotoxicity on human corneal epithelial cells, maintaining cell viability exceeding 80% after 72 hours. In the rabbit model:

G-AM-P exhibited excellent ocular tolerance, significantly facilitated corneal re-epithelialization, and did not provoke inflammation, neovascularization, or stromal haze.