Abstract: A synthetic calcium phosphate-based biomedical material comprising gadolinium. The material may comprises a compound having the general chemical formula: Ca10?yGdy(PO4)6?x(SiO4)x(OH)2?x+y where 0<x<1.3 and 0<y<1.3.

Abstract: A synthetic calcium phosphate-based biomedical material comprising gadolinium. The material may comprises a compound having the general chemical formula: Ca10?yGdy(PO4)6?x(SiO4)x(OH)2?x+y where 0<x<1.3 and 0<y<1.3.

Abstract: A synthetic calcium phosphate-based biomedical material comprising gadolinium. The material may comprises a compound having the general chemical formula: Ca10?yGdy(PO4)6?x(SiO4)x(OH)2?c+y where 0<x<1.3 and 0<y<1.3.

Abstract: A synthetic calcium phosphate-based biomedical material comprising gadolinium. The material may comprises a compound having the general chemical formula: Ca10?yGdy(PO4)6?x(SiO4)x(OH)2?c+y where 0<x<1.3 and 0<y<1.3.

Abstract: A synthetic calcium phosphate-based biomedical material comprising gadolinium. The material may comprise a compound having the general chemical formula: Ca10?yGdy(PO4)6?x(SiO4)x(OH)2?x+y where 0<x<1.3 and 0<y<1:3.

Abstract: The invention relates to porous granular calcium phosphate osteoinductive materials, particularly materials useful in body tissue repair, principally bone repair and bone replacement, and also to the use of such materials and to a method of making such materials. Exemplary materials comprise discrete porous granules each containing crystals of at least one calcium phosphate, wherein (i) at least 90% of said crystals of the granules have a crystal size in the range 10-100 nm, (ii) at least 90% of the pores in the granules have a pore size in the range 10-500 nm, (iii) the average pore size of the pores having pore size in the range 10-500 nm in the granules is in the range 30-90 nm, (iv) the total volume porosity of the granules is at least 50%, and (v) the surface area of the granules is in the range 10-70 m2/g.

Abstract: The bone graft system comprises a solid inorganic component, which is bone graft material, and a hydrogel. The hydrogel contains >2 ppm of silicon ions, calculated as parts by weight of Si per million of the aqueous component of the hydrogel. Preferably, the solid inorganic component comprises hydroxyapatite or a silicon-containing hydroxyapatite, and may be a silicon-containing hydroxyapatite having a Ca/P ratio in the range 2.05 to 2.55 and a Ca/(P+Si) molar ratio less than 1.66. Bone healing is promoted by delivery of silicon ion release from the hydrogel and by the solid inorganic component stimulating cell behavior.

Abstract: A process for the synthesis of a bioceramic composition comprising calcium phosphosilicate (CPS, Ca10(PO4)4(SiO4)2), the process comprising: providing calcium or a calcium-containing compound, a phosphorus-containing compound and a silicon-containing compound; and forming a precipitate by reacting the compounds in an aqueous phase at an alkali pH.

Abstract: The invention relates to porous granular calcium phosphate osteoinductive materials, particularly materials useful in body tissue repair, principally bone repair and bone replacement, and also to the use of such materials and to a method of making such materials. Exemplary materials comprise discrete porous granules each containing crystals of at least one calcium phosphate, wherein (i) at least 90% of said crystals of the granules have a crystal size in the range 10-100 nm, (ii) at least 90% of the pores in the granules have a pore size in the range 10-500 nm, (iii) the average pore size of the pores having pore size in the range 10-500 nm in the granules is in the range 30-90 nm, (iv) the total volume porosity of the granules is at least 50%, and (v) the surface area of the granules is in the range 10-70 m2/g.

Abstract: A process for the synthesis of a bioceramic composition comprising calcium phosphosilicate (CPS, Ca10(PO4)4(SiO4)2), the process comprising: providing calcium or a calcium-containing compound, a phosphorus-containing compound and a silicon-containing compound; and forming a precipitate by reacting the compounds in an aqueous phase at an alkali pH.

Abstract: A process for the synthesis of a bioceramic composition comprising calcium phosphosilicate (CPS, Ca10(PO4)4(SiO4)2), the process comprising: providing calcium or a calcium-containing compound, a phosphorus-containing compound and a silicon-containing compound; and forming a precipitate by reacting the compounds in an aqueous phase at an alkali pH.

Abstract: An inorganic silicate-substituted calcium phosphate hydroxyapatite, useful as a biomaterial, has a Ca/P molar ratio in the range 2.05 to 2.55 and a Ca/(P+Si) molar ratio less than 1.66. The hydroxyapatite can be substantially free of carbonate ions. The material has relatively high solubility and is able to release silicon into solution.

Abstract: The bone graft system comprises a solid inorganic component, which is bone graft material, and a hydrogel. The hydrogel contains >2 ppm of silicon ions, calculated as parts by weight of Si per million of the aqueous component of the hydrogel. Preferably, the solid inorganic component comprises hydroxyapatite or a silicon-containing hydroxyapatite, and may be a silicon-containing hydroxyapatite having a Ca/P ratio in the range 2.05 to 2.55 and a Ca/(P+Si) molar ratio less than 1.66. Bone healing is promoted by delivery of silicon ion release from the hydrogel and by the solid inorganic component stimulating cell behavior.

Abstract: A synthetic calcium phosphate-based biomedical material comprising gadolinium. The material may comprise a compound having the general chemical formula: Ca10?yGdy(PO4)6?x(SiO4)x(OH)2?z+y where 0<x<1.3 and 0<y<1.3.

Abstract: An inorganic silicate-substituted calcium phosphate hydroxyapatite, useful as a biomaterial, has a Ca/P molar ratio in the range 2.05 to 2.55 and a Ca/(P+Si) molar ratio less than 1.66. The hydroxyapatite can be substantially free of carbonate ions. The material has relatively high solubility and is able to release silicon into solution.

Abstract: Biomedical materials and, in particular, to substituted calcium phosphate (e.g. apatite and hydroxyapatite) materials for use as synthetic bone. A synthetic calcium phosphate comprising silicon and a trivalent cation having a formula Ca10?yMy(PO4)6?x(SiO4)x(OH)2?x+y where M is a trivalent cation, 0<x<1.3 and 0<y<1.3. The trivalent cation is one or more of yttrium, scandium, aluminium and the Lanthanide elements. Preferably, the trivalent cation is or comprises yttrium. The trivalent cation is believed to substitute for the calcium ion in the hydroxyapatite lattice.

Abstract: A process for the preparation of a single phase magnesium- and carbonate-substituted hydroxyapatite composition, which process comprises the steps of (i) preparing an aqueous solution containing CO32− and PO43− ions in the substantial absence of cations other than H+ ions; (ii) mixing the solution from step (i) with an aqueous calcium- and magnesium-containing solution or suspension; and (iii) collecting and drying the precipitate formed in step (ii); the ratio of (Ca+Mg/P) in the calcium- and magnesium-containing solution or suspension and the phosphorus-containing solution, when mixed together, being maintained at 1.67, or above. The product of the process is novel and comprises up to 0.5% magnesium and up to 1% of carbonate substituted into the hydroxyapatite structure and which does not contain Na+ or NH4+ ions, the ratio of (Ca+Mg/P) being greater than 1.67.

Abstract: A process for the preparation of a single phase carbonate-substituted hydroxyapatite composition, which process comprises the steps of (i) preparing an aqueous solution containing Co32− and PO43− ions in the substantial absence of cations other than H+ ions: (ii) mixing the solution from step (i) with an aqueous solution or suspension of a calcium compound; and (iii) collecting and drying the precipitate formed in step (ii); the ratio of Ca/P in the calcium-containing solution or suspension and the phosphorus-containing solution, when mixed together, being maintained above 1.67. The product of the process is novel with a Ca/P molar ratio of greater than 1.67 and comprises up to 5% by weight of CO32− ions substituted in the B site or the B and A sites of the hydroxyapatite structure, with at least 50% of the CO32− ions being substituted on the B site. This product does not contain Na+ or NH4+ ions.

Abstract: The present invention provides a synthetic silicon-substituted apatite or hydroxyapatite which comprises 0.1% to 5% by weight of silicon. The silicon-substituted apatite or hydroxyapatite may be used as a synthetic bone material for use in bone substitution, implants, fillers and cements, coatings for metallic implants, and for making hydroxyapatite-polymer composites. The silicon-substituted apatite is prepared by reacting a calcium salt or calcium hydroxide with orthophosphoric acid or a salt of orthophosphoric acid in the presence of a silicon-containing compound, the molar ratio of calcium ions to phosphorous-containing ions being from 1:0.5 to 1:0.7 and the molar ratio of calcium ions to silicon-containing ions being at least 1:0.2, whereby a precipitate of a silicon-substituted apatite is formed. On heating and/or sintering the silicon-substituted apatite at a temperature of from 500° C. to 1400° C.