title: Biological response of laser macrostructured and oxidized titanium alloy: an in vitro and in vivo study.
abstract: OBJECTIVE
  To assess both the in vitro and in vivo biological response of a laser modified surface in an integrated manner. A combined innovative approach applies lasers to macrostructure as well as to oxidize the surface of titanium alloy implants.
  
  
  METHODS
  A Nd:YAG marking and ArF excimer lasers were used for macrostructuring and UV-oxidizing the surface of Ti6Al4V discs, respectively. Human fetal osteoblastic cell culture and a sheep tibia model were used to assess the cell response and the osseogeneration capability of as-machined, laser macrostructured and laser macrostructured and oxidized surfaces.
  
  
  RESULTS
  In vitro: Laser macrostructuration alone did not promote cell response. Cellular proliferation was enhanced by the additional UV laser oxidation. In vivo: A greater significant percentage of bone-implant contact was obtained for both laser treated surfaces compared to machine-turned control samples, three months after implantation, in spite of the low cellular response for macrostructured samples. The use of sheep model for six months appears to be less adequate for a comparison because of the high level of bone integration in all samples. In spite of the often reported positive effect of titanium oxidation on the triggering of faster osseointegration, in this experiment the additional UV laser oxidation did not lead to a significant in vivo improvement.
  
  
  CONCLUSIONS
  Laser macrostructuration of titanium alloy surfaces appears to promote bone apposition and may therefore constitute a promising surface modification strategy. In animal models, the natural process of titanium surface oxidation, because of physiologic fluids, alters properties observed in vitro with cells.
authors.affiliation: Department of Applied Physics, E.T.S.I. Industriales, University of Vigo, Spain.
authors.forename: María Dolores
authors.initials: MD
authors.lastname: Paz
authors.forename: J Iñaki
authors.initials: JI
authors.lastname: Álava
authors.forename: Leire
authors.initials: L
authors.lastname: Goikoetxea
authors.forename: Stefano
authors.initials: S
authors.lastname: Chiussi
authors.forename: Idoia
authors.initials: I
authors.lastname: Díaz-Güemes
authors.forename: Jesus
authors.initials: J
authors.lastname: Usón
authors.forename: Francisco
authors.initials: F
authors.lastname: Sánchez
authors.forename: Betty
authors.initials: B
authors.lastname: León
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000737:chemistry* / Q000494:pharmacology* / Q000528:radiation effects; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D007834:Lasers; D008422:Materials Testing; D010006:Osteoblasts / Q000187:drug effects / Q000502:physiology*; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology; D010084:Oxidation-Reduction; D012756:Sheep; D013977:Tibia / Q000166:cytology* / Q000254:growth & development* / Q000601:surgery; D014025:Titanium / Q000737:chemistry* / Q000494:pharmacology* / Q000528:radiation effects
chemical_list: D018786:Bone Substitutes; D014025:Titanium