Calcium-strontium mixed phosphate as novel injectable and radio-opaque hydraulic cement.
Sterile calcium hydrogenophosphate dihydrate (DCPD) (CaHPO(4).2H(2)O), calcium oxide and strontium carbonate powders were mixed in various liquid phases. Among these, ammonium phosphate buffer (0.75 M, pH 6.9) led to a novel strontium-containing calcium phosphate cement. At a 6/2.5/1.5 M ratio and for a liquid to powder ratio (L/P) of 0.5 mlg(-1), the initial paste was fluid and remained injectable for 12 min at 25 degrees C. It was easily obtained by mixing sterile powders and the liquid phase using the push-pull technique, avoiding complex mixing apparatus. The cement set after 15 min at 37 degrees C and was hard after 1h. The compressive strength was in the 20 MPa range, a value higher than that generally assigned to trabecular bone (5-15MPa). This strength appeared sufficient for repairing non-loading sites or reinforcing osteoporotic vertebrae (vertebroplasty). After setting, the initial mixture formed a strontium-calcium-deficient carbonate apatite. The radio-opacity of the resulting cement was three times greater than that of cortical bone because of the presence of strontium ions, a feature that complies with the requirements for vertebroplasty. Furthermore, the cement powder remained stable and retained its properties for at least 4 years.
Université Montpellier 1, Institut des Biomolécules Max Mousseron UMR CNRS 5247, Département Biopolymères Artificiels, Faculté de Pharmacie de Montpellier, 15 Avenue Charles Flahault, BP 14491, 34093 Montpellier Cedex 5, France.
Guilhem
G
Romieu
Xavier
X
Garric
Sylvie
S
Munier
Michel
M
Vert
Philippe
P
Boudeville
D001843:Bone Cements / Q000528:radiation effects*; D017610:Calcium Compounds / Q000737:chemistry; D002130:Calcium Phosphates / Q000494:pharmacology*; D002254:Carbonates / Q000494:pharmacology; D019245:Compressive Strength / Q000187:drug effects; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007267:Injections; D007700:Kinetics; D010087:Oxides / Q000737:chemistry; D010710:Phosphates / Q000494:pharmacology*; D011208:Powders; D017550:Spectroscopy, Fourier Transform Infrared; D013324:Strontium / Q000494:pharmacology*; D013997:Time Factors; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
D001843:Bone Cements; D017610:Calcium Compounds; D002130:Calcium Phosphates; D002254:Carbonates; D010087:Oxides; D010710:Phosphates; D011208:Powders; D014867:Water; C054286:strontium carbonate; C020243:calcium phosphate; C052774:strontium phosphate; C016538:lime; D013324:Strontium