A simple, cross-linked collagen tissue substitute for corneal implantation

Area of Science:

• Biomaterials Science
• Ophthalmology
• Tissue Engineering

Background:

• Corneal transplantation faces challenges due to donor scarcity and rejection.
• Developing synthetic or bio-engineered corneal substitutes is crucial for addressing these limitations.

Purpose of the Study:

• To develop a simple, optically clear corneal substitute using cross-linked collagen.
• To evaluate the biocompatibility and efficacy of this collagen substitute in animal models.

Main Methods:

• Porcine type I collagen was cross-linked using EDC/NHS chemistry.
• The collagen solution was molded, cured, and implanted via lamellar keratoplasty in rabbits and minipigs.
• Post-implantation evaluation included clinical, confocal, topographic, and histopathologic assessments over six months.

Main Results:

• The cross-linked collagen substitute exhibited superior optical clarity (refractive index 1.35) compared to human corneas.
• Implants demonstrated excellent biocompatibility with minimal haze (1/24) and no adverse reactions over six months.
• The material promoted corneal cell, nerve, and tear film regeneration, restoring touch sensitivity and maintaining corneal thickness.

Conclusions:

• Water-soluble carbodiimides effectively stabilize collagen for fabricating corneal matrix substitutes.
• This straightforward cross-linking method facilitates the production of corneal substitutes for transplantation.
• The developed material presents a viable option for addressing cornea shortages and for emergency corneal repair.