PROPERTIES OF CALCIUM-PHOSPHATE PASTE WITH HOLLOW SPHERICAL Β-Calcium-Orthophosphate AGGLOMERATES

Abstract

The spherical β-calcium orthophosphate (β-Ca 3 (PO 4) 2 : β-TCP) agglomerates have been prepared by a spray-pyrolysis technique. The hollow spherical agglomerates were obtained by heating the spray-pyrolyzed powder at 900 for 10 min. The cylindrical specimen was fabricated mixing the calcium-phosphate paste (CPP) with 10-50 mass% β-TCP agglomerates, using malaxation liquid. The setting time of CPP specimen increased from 8.5 to 17 min with increasing amount of β-TCP from 10 to 50 mass%. The CPP specimens with β-TCP addition were immersed into the simulated body fluid (SBF) at 37±0.2 for various times. The compressive strengths of CPP specimens with β-TCP addition reached maxima, e.g., 42.8 MPa for 10 mass% β-TCP addition and 7.5 MPa for 50 mass% β-TCP addition, respectively, after the immersion of these specimens in SBF for 3-7 d. Crystalline phases of the CPP specimens after the immersion in SBF for 7 d were HAp and β-TCP. The total porosity of CPP specimen increased with increasing amount of β-TCP and attained 67.1% for 50 mass% β-TCP addition.

Large scale production of yolk–shell β-tricalcium phosphate powders, and their bioactivities as novel bone substitutes

“…[4][5][6] For these reasons, b-TCP is frequently used as a bone graft material, and also as a drug or gene delivery vehicle; consequently, various b-TCP structures have been investigated. 2,[7][8][9][10][11][12][13][14][15][16] Among them, porous and hollow forms have been extensively studied because of their large surface areas and loading capacity. 3,[14][15][16][17][18][19][20][21] For example, Musha et al 15 synthesized submicron-sized hollow b-TCP powders by spray pyrolysis; it was subsequently mixed with calcium-phosphate paste for use as a cement, enhancing its bioabsorbability.…”

“…2,[7][8][9][10][11][12][13][14][15][16] Among them, porous and hollow forms have been extensively studied because of their large surface areas and loading capacity. 3,[14][15][16][17][18][19][20][21] For example, Musha et al 15 synthesized submicron-sized hollow b-TCP powders by spray pyrolysis; it was subsequently mixed with calcium-phosphate paste for use as a cement, enhancing its bioabsorbability. Paul et al 16 prepared porous b-TCP microspheres by precipitation for oral delivery of insulin; with this microsphere-based delayed-release formulation, a decrease in the elevated glucose level in rats with induced diabetes was demonstrated.…”

Preparation of Porous Spherical Hydroxyapatite Agglomerates Interacted With Cyclodextrin

“…1 The present authors have paid attention to the properties of HAp powder prepared by spray-pyrolysis with the aim of manufacturing biomaterials. [2][3][4][5] Spray pyrolysis is a technique where a solution containing desired types and amounts of metal ions is sprayed into the "hot zone" of an electric furnace. 6 Since the individual sprayed droplet is instantaneously heated within the furnace, the resulting powder has the following characteristics: (i) the formation of spherical agglomerates reflecting the external droplet shape, (ii) the formation of nanometer-sized primary particles due to the very short heating time of the droplets, and (iii) little chemical segregation, due to flash solidification.…”

Effect of colloidal silica addition on the formation of porous spherical .ALPHA.-calcium orthophosphate agglomerates by spray pyrolysis technique

“…As the calcium-phosphate paste chiefly includes Ca4(PO4)2O (18.0 mass%) and CaHPO4•2H2O, together with α-TCP (74.9 mass%), the chemical reaction to form HAp may be expressed as follows: 22) 2Ca3(PO4)2 + Ca4O(PO4)2 + H2O → Ca10(PO4)6(OH)2 (2)…”