Collagen-phosphorylcholine interpenetrating network hydrogels as corneal substitutes

Area of Science:

• Biomaterials Science
• Ophthalmology
• Tissue Engineering

Background:

• Corneal diseases necessitate advanced regenerative therapies.
• Existing treatments face limitations in efficacy and safety.
• Biointeractive materials offer promising solutions for corneal repair.

Purpose of the Study:

• To fabricate and characterize a novel biointeractive collagen-phospholipid corneal substitute.
• To evaluate the mechanical, optical, and biological properties of the engineered hydrogel.
• To assess the in vivo efficacy of the corneal substitute for tissue regeneration.

Main Methods:

• Fabrication of interpenetrating polymeric networks from crosslinked collagen and poly(ethylene glycol) diacrylate-MPC.
• Assessment of mechanical strength, enzymatic/UV degradation resistance, and optical properties (refractive index, transmission, backscatter).
• In vivo implantation into mini-pigs to evaluate corneal tissue, tear film, and nerve regeneration over 12 months.

Main Results:

• The collagen-MPC hydrogels exhibited enhanced mechanical strength and stability against degradation.
• The substitute promoted corneal cell and nerve in-growth, retaining collagen's biointeractive properties.
• Optical and permeability properties were comparable or superior to human corneas.
• Twelve-month implantation showed regeneration of corneal tissue, tear film, and nerves.
• Substitution with recombinant human collagen yielded a fully synthetic, disease-free implant.

Conclusions:

• The developed collagen-phospholipid corneal substitute is a promising biomaterial for corneal regeneration.
• It offers superior mechanical and optical characteristics while promoting native tissue integration.
• The potential for a fully synthetic, safe, and effective corneal implant is demonstrated.