title: Degradation studies and biological behavior on an artificial cornea material.
abstract: OBJECTIVE
  Patients with dry eye syndrome, Stevens-Johnson syndrome, or recurrent transplant rejections are unsuitable to receive a keratoprosthesis. The present work aims at developing a highly biocompatible keratoprosthesis that could be successfully implanted in such patients.
  
  
  METHODS
  Glass-reinforced hydroxyapatite (GRHA) was used to construct this new artificial cornea. To grant the device an adequate porosity, a porogen agent was added in the following percentages: 10, 30, and 50%. Samples were physicochemically analyzed in terms of density, porosity, roughness, degradation, and surface imaging. Biological relevance was assessed by cell culture, MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrasodium bromide) assays, and cell imaging.
  
  
  RESULTS
  Samples B (30% porogen) and C (50% porogen) were found to be the most porous and also had the roughest topography. Degradation studies showed that under simulated physiologic conditions, no mass loss was found. Conversely, under acidic conditions, a significant mass loss was found. The biological performance of these samples was satisfactory when cultured with human fibroblasts. The MTT assay revealed that samples B and C had greater propensity to cell invasion and proliferation than that of the other tested materials. Cell imaging demonstrated that fibroblasts organized around the pore edges before colonizing it.
  
  
  CONCLUSIONS
  A material with physicochemical and biological characteristics close to an ideal artificial cornea has been fabricated. The GRHA cornea containing 30% porogen is the most promising substitute material due to the biological performance, adequate porosity, and low degradation propensity.
authors.affiliation: CEMUC, Departamento de Engenharia Metalúrgica e dos Materiais, Faculdade de Engenharia, Universidade do Porto, Portugal.livia@fe.up.pt
authors.forename: Lívia
authors.initials: L
authors.lastname: Santos
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Ferraz
authors.forename: Yuki
authors.initials: Y
authors.lastname: Shirosaki
authors.forename: Maria Ascensão
authors.initials: MA
authors.lastname: Lopes
authors.forename: Maria Helena
authors.initials: MH
authors.lastname: Fernandes
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Osaka
authors.forename: José Domingos
authors.initials: JD
authors.lastname: Santos
mesh_terms: D001187:Artificial Organs; D002478:Cells, Cultured; D003315:Cornea; D015352:Dry Eye Syndromes / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008768:Methylmethacrylates; D016062:Porosity
chemical_list: D008768:Methylmethacrylates