title: Biofunctional alendronate-Hydroxyapatite thin films deposited by Matrix Assisted Pulsed Laser Evaporation.
abstract: We applied Matrix Assisted Pulsed Laser Evaporation (MAPLE) in order to synthesize alendronate-hydroxyapatite thin films on titanium substrates. Alendronate-hydroxyapatite composite nanocrystals with increasing bisphosphonate content (0, 3.9, 7.1%wt) were synthesized in aqueous medium. Then, they were suspended in deionised water, frozen at liquid nitrogen temperature and used as targets for MAPLE experiments. The depositions were conducted with a KrF* excimer laser source (l=248nm, t(FWHM)=25ns) in mild conditions of temperature and pressure. The obtained thin films had a good crystallinity, which slightly decreases with the increase of alendronate content, and exhibited a porous-like structure. Osteoblast-like MG63 cells and human osteoclasts were cultured on the thin films up to 14 days. In the presence of alendronate, MG63 cells displayed a normal morphology, increased proliferation and higher values of differentiation parameters, namely type I collagen, osteocalcin, and osteoprotegerin/TNF-related activation-induced cytokine receptor ratio. In contrast, osteoclasts showed significantly reduced proliferation, and increased level of Caspase 3. Moreover, the coatings synthesized from hydroxyapatite at relatively high bisphosphonate content (7.1% wt) displayed a reduced production of Tumour Necrosis Factor alpha (TNF-alpha) and Interleukin 6 (IL-6), suggesting a down-regulatory role of alendronate on the inflammatory reaction. The successful deposition of alendronate modified hydroxyapatite thin films yields coatings with enhanced bioactivity, able to promote osteoblast differentiation and to inhibit osteoclast proliferation.
authors.affiliation: Department of Chemistry G. Ciamician, University of Bologna, via Selmi 2, 40126 Bologna, Italy. adriana.bigi@unibo.it
authors.forename: Adriana
authors.initials: A
authors.lastname: Bigi
authors.forename: Elisa
authors.initials: E
authors.lastname: Boanini
authors.forename: Chiara
authors.initials: C
authors.lastname: Capuccini
authors.forename: Milena
authors.initials: M
authors.lastname: Fini
authors.forename: Ion N
authors.initials: IN
authors.lastname: Mihailescu
authors.forename: Carmen
authors.initials: C
authors.lastname: Ristoscu
authors.forename: Felix
authors.initials: F
authors.lastname: Sima
authors.forename: Paola
authors.initials: P
authors.lastname: Torricelli
mesh_terms: D019386:Alendronate / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D017886:Durapatite / Q000737:chemistry*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000009:adverse effects / Q000737:chemistry / Q000648:ultrastructure; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects; D014025:Titanium / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D017886:Durapatite; D014025:Titanium; D019386:Alendronate