title: Sr-substituted hydroxyapatites for osteoporotic bone replacement.
abstract: Porous apatites, which during resorption can release in situ Sr ions, were prepared to associate an anti-osteoporotic action with the peculiar features of the inorganic phase constituting the bone. Sr-substituted hydroxyapatite (SrHA) powder was directly synthesized using the classical neutralization route, but including Sr ions, and characterized. The higher solubility of SrHA granules of 400-600 microm size, potentially usable as a bone filler, was assessed compared with that of analogous stoichiometric HA granules. The Sr released in synthetic body fluid became constant after 1 week. The Ca release is improved for SrHA compared with stoichiometric HA, due to the higher solubility of the first material. Porous scaffolds with micro-macro interconnected porosity, which mimic the morphology of the spongy bone, were prepared by the impregnation of cellulose sponges with suspensions of the powder and a specific sintering process. A compressive strength of 4.52+/-1.40 MPa was obtained for SrHA scaffolds characterized with 45 vol.% of porosity. Promising biomedical applications, such as resorbable bone filler or bone substitute releasing in situ Sr ions for a prolonged time, can be hypothesized for the SrHA materials when pathologies related with Sr deficiency are present.
authors.affiliation: ISTEC-CNR, Institute of Science and Technology for Ceramics, National Research Council, via Granarolo 64, 48018 Faenza (RA), Italy. elena@istec.cnr.it
authors.forename: Elena
authors.initials: E
authors.lastname: Landi
authors.forename: Anna
authors.initials: A
authors.lastname: Tampieri
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Celotti
authors.forename: Simone
authors.initials: S
authors.lastname: Sprio
authors.forename: Monica
authors.initials: M
authors.lastname: Sandri
authors.forename: Giandomenico
authors.initials: G
authors.lastname: Logroscino
mesh_terms: D018786:Bone Substitutes / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry; D003198:Computer Simulation; D006863:Hydrogen-Ion Concentration; D006882:Hydroxyapatites / Q000737:chemistry*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010024:Osteoporosis / Q000601:surgery; D016062:Porosity; D017550:Spectroscopy, Fourier Transform Infrared; D013324:Strontium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D018786:Bone Substitutes; D006882:Hydroxyapatites; D002118:Calcium; D013324:Strontium