title: Artificial human corneas: scaffolds for transplantation and host regeneration.
abstract: OBJECTIVE
  To review the development of artificial corneas (prostheses and tissue equivalents) for transplantation, and to provide recent updates on our tissue-engineered replacement corneas.
  
  
  METHODS
  Modified natural polymers and synthetic polymers were screened for their potential to replace damaged portions of the human cornea or the entire corneal thickness. These polymers, combined with cells derived from each of the three main corneal layers or stem cells, were used to develop artificial corneas. Functional testing was performed in vitro. Trials of biocompatibility and immune and inflammatory reactions were performed by implanting the most promising polymers into rabbit corneas.
  
  
  RESULTS
  Collagen-based biopolymers, combined with synthetic crosslinkers or copolymers, formed effective scaffolds for developing prototype artificial corneas that could be used as tissue replacements in the future. We have previously developed an artificial cornea that mimicked key morphologic and functional properties of the human cornea. The addition of synthetic polymers increased its toughness as it retained transparency and low light scattering, making the matrix scaffold more suitable for transplantation. These new composites were implanted into rabbits without causing any acute inflammation or immune response. We have also fabricated full-thickness composites that can be fully sutured. However, the long-term effects of these artificial corneas need to be evaluated.
  
  
  CONCLUSIONS
  Novel tissue-engineered corneas that comprise composites of natural and synthetic biopolymers together with corneal cell lines or stem cells will, in the future, replace portions of the cornea that are damaged. Our results provide a basis for the development of both implantable temporary and permanent corneal replacements.
authors.affiliation: University of Ottawa Eye Institute, University of Ottawa, Ontario, Canada. mgriffith@ohri.ca
authors.forename: May
authors.initials: M
authors.lastname: Griffith
authors.forename: Malik
authors.initials: M
authors.lastname: Hakim
authors.forename: Shigeto
authors.initials: S
authors.lastname: Shimmura
authors.forename: Mitchell A
authors.initials: MA
authors.lastname: Watsky
authors.forename: Fengfu
authors.initials: F
authors.lastname: Li
authors.forename: David
authors.initials: D
authors.lastname: Carlsson
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Doillon
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Nakamura
authors.forename: Erik
authors.initials: E
authors.lastname: Suuronen
authors.forename: Naoshi
authors.initials: N
authors.lastname: Shinozaki
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Nakata
authors.forename: Heather
authors.initials: H
authors.lastname: Sheardown
mesh_terms: D000818:Animals; D001187:Artificial Organs; D003315:Cornea / Q000502:physiology; D016039:Corneal Transplantation; D006801:Humans; D020007:Implants, Experimental; D011817:Rabbits; D012038:Regeneration