title: Bioactive, nanostructured Si-substituted hydroxyapatite coatings on titanium prepared by pulsed laser deposition.
abstract: OBJECTIVE
  The aim of this work was to deposit silicon-substituted hydroxyapatite (Si-HAp) coatings on titanium for biomedical applications, since it is known that Si-HAp is able to promote osteoblastic cells activity, resulting in the enhanced bone ingrowth.
  
  
  METHODS
  Pulsed laser deposition (PLD) method was used for coatings preparation. For depositions, Si-HAp targets (1.4 wt % of Si), made up from nanopowders synthesized by wet method, were used.
  
  
  RESULTS
  Microstructural and mechanical properties of the produced coatings, as a function of substrate temperature, were investigated by scanning electron and atomic force microscopies, X-ray diffraction, Fourier transform infrared spectroscopy, and Vickers microhardness. In the temperature range of 400-600°C, 1.4-1.5 µm thick Si-HAp films, presenting composition similar to that of the used target, were deposited. The prepared coatings were dense, crystalline, and nanostructured, characterized by nanotopography of surface and enhanced hardness. Whereas the substrate temperature of 750°C was too high and led to the HAp decomposition. Moreover, the bioactivity of coatings was evaluated by in vitro tests in an osteoblastic/osteoclastic culture medium (α-Modified Eagle's Medium).
  
  
  CONCLUSIONS
  The prepared bioactive Si-HAp coatings could be considered for applications in orthopedics and dentistry to improve the osteointegration of bone implants.
authors.affiliation: Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere, 100-00133, Rome, Italy.
authors.forename: Julietta V
authors.initials: JV
authors.lastname: Rau
authors.affiliation: Università di Roma "Niccolò Cusano", Via Don Carlo Gnocchi, 3-00166, Rome, Italy.|Dipartimento di Ingegneria dell'Impresa, Università di Roma "Tor Vergata", UdR INSTM-"Roma Tor Vergata", Via del Politecnico, 1-00133, Rome, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Cacciotti
authors.affiliation: Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, 00016, Monterotondo Scalo (RM), Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Laureti
authors.affiliation: Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Via del Fosso del Cavaliere, 100-00133, Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Fosca
authors.affiliation: Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, 00016, Monterotondo Scalo (RM), Italy.
authors.forename: Gaspare
authors.initials: G
authors.lastname: Varvaro
authors.affiliation: Dipartimento di Chimica, Università di Roma "La Sapienza", Piazzale Aldo Moro, 5-00185, Rome, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Latini
mesh_terms: D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D007834:Lasers; D049329:Nanostructures / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D017886:Durapatite; D014025:Titanium
keywords: bioactivity; physico-chemical properties; pulsed laser deposition; silicon-substituted hydroxyapatite coatings; titanium