Development of Sr and CO3 co-substituted hydroxyapatites for biomedical applications.
Sr and CO3 co-substituted hydroxyapatite (SrCHA) nanopowder was synthesized by neutralization. The powder was characterized. The improved solubility in Hanks' balanced solution of SrCHA granules (400-600 microm of dimensional range), potentially usable as bone filler, was assessed and compared with that of an analogous carbonate free granulate. SrCHA porous bodies with interconnected micro- and macro-porosity, which mimic the morphology of spongy bone, were prepared by the impregnation of cellulose sponges with suspensions of the SrCHA powder and controlled sintering. SrCHA porous scaffolds sintered at 850 degrees C, in flowing CO2 atmosphere, showed satisfying compressive strength (4.58+/-0.75 MPa) for a porosity value of 45 vol.% and retained the desired ionic substitutions (Sr/Ca=0.11 and CO3=6.8 wt.%). The possibility of widely modulating, by acting on the chemical-physical-geometrical features of the material, the prolonged in situ release of therapeutic Sr, together with the fundamental (Ca, PO4) and main substituting (CO3) ions that constitute the bone mineral phase, makes the use of SrCHA as resorbable bone filler or bone substitute scaffolds promising, especially when pathologies related with Sr deficiency are present. In vitro and in vivo tests are in progress.
Landi
Elena
E
ISTEC-CNR, Institute of Science and Technology for Ceramics, National Research Council, via Granarolo 64, 48018 Faenza (RA), Italy. elena@istec.cnr.it
Sprio
Simone
S
Sandri
Monica
M
Celotti
Giancarlo
G
Tampieri
Anna
A
D002254:Carbonates / Q000737:chemistry*; D019245:Compressive Strength; D004055:Differential Thermal Analysis; D017886:Durapatite / Q000138:chemical synthesis*; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D011208:Powders / Q000138:chemical synthesis; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013324:Strontium / Q000737:chemistry*; D013814:Thermal Conductivity; D013818:Thermogravimetry; D014961:X-Ray Diffraction
D002254:Carbonates; D011208:Powders; D017886:Durapatite; D013324:Strontium