Artificial Lamellar Cornea Based On Poly(ethylene Glycol) And Poly(acrylic Acid)

Abstract

Purpose: : To design an artificial lamellar cornea capable of supporting re-epithelialization and implantation without staged procedures or a donor corneal carrier.

Methods: : A mechanically strong and nutrient-permeable hydrogel composed of an interpenetrating network of poly(ethylene glycol) and poly(acrylic acid) (PEG/PAA) was cast with a diameter of 7-mm and raised central button of 3-mm in diameter. After sterilization through autoclaving, the hydrogel was treated with chemical crosslinkers EDC and NHS to covalently bind bovine collagen Type I and bovine fibronectin to the hydrogel surface. For in vitro experiments, immortalized human corneal epithelial cells were seeded on top of the artificial cornea at a density of 2.5 x 10^4 cells/mL and cultured for two weeks. Molded hydrogels without epithelial cells were implanted into a stromal pocket in enucleated rabbit eyes created with the Keramed RoboTome Cornea Pocket Maker.

Results: : The surface-modified hydrogel supported a confluent growth of human corneal epithelial cells in culture. Cells stained positively for cytokeratin 3, indicating their corneal epithelial phenotype. The artificial cornea could be manipulated to fit into an 8-mm uniform circular stromal pocket created at a depth of 300 µm, such that the raised central button fit within the trephined anterior cornea.

Conclusions: : An artificial lamellar cornea has been designed with a PEG/PAA hydrogel that possesses high mechanical strength and nutrient permeability, and has the potential to support re-epithelialization.

Keywords: keratoprostheses • cornea: epithelium • cornea: stroma and keratocytes