[Frontiers in Bioscience 14, 3326-3337, January 1, 2009]

Bioengineered corneas for transplantation and in vitro toxicology

Christopher R. McLaughlin1,2, Ray J-F Tsai3 , Malcolm A. Latorre1,4, May Griffith1,2

1University of Ottawa Eye Inst, 501 Smyth Road, Ottawa, ON K1H 8L6, Canada, 2Dept. of Cellular and Molecular Medicine, Univ. of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada, 3Taipei Eye Center, Taipei Medical University, Taipei, Taiwan, 4 Dept. of Physics, Univ. of Ottawa, 150 Louis Pasteur, Ottawa ON,  K1N 6N5, Canada

TABLE OF CONTENTS

1. Abstract
2. Introduction
2.1. The cornea as a target organ for repair and regeneration
2.2. Corneal substitutes for in vitro testing
3. Corneal substitutes for transplantation
3.1. Completely synthetic corneal replacements: keratoprostheses
3.2. Keratoprostheses with cell coverage
3.3. Self-assembled corneal substitutes
3.4. Biomimetic corneal implants
4. In situ repair and enhancement of weak corneas
5. Tissue engineered scaffolds for delivery of corneal stem and progenitor cells
6. In vitro corneal models
6.1. Tissue engineered full thickness models
6.2. Innervated corneal model
7. Conclusion
8. Acknowledgements
9. References

1. ABSTRACT

Bioengineered corneas have been designed to replace partial or the full-thickness of defective corneas, as an alternative to using donor tissues. They range from prosthetic devices that solely address replacement of the cornea's function, to tissue engineered hydrogels that permit regeneration of host tissues. In cases where corneal stem cells have been depleted by injury or disease, most frequently involving the superficial epithelium, tissue engineered lamellar implants reconstructed with stem cells have been transplanted. In situ methods using ultraviolet A (UVA) crosslinking have also been developed to strengthen weakened corneas. In addition to the clinical need, bioengineered corneas are also rapidly gaining importance in the area of in vitro toxicology, as alternatives to animal testing. More complex, fully innervated, physiologically active, three-dimensional organotypic models are also being tested.