TY - JOUR
T1 - A novel strategy for preparing nanoporous biphasic calcium phosphate of controlled composition via a modified nanoparticle-assembly method
AU - Fujiwara, Keiko
AU - Okada, Masahiro
AU - Takeda, Shoji
AU - Matsumoto, Naoyuki
N1 - Funding Information:
The SEM observations, XRD measurements, and in vitro tests were performed at the Institute of Dental Research, Osaka Dental University. This study was supported in part by JSPS KAKENHI grant number 23792301 and by a grant program of the Feasibility Study Stage in Adaptable and Seamless Technology Transfer Program through Target-driven R&D (A-STEP; ID: AS231Z01647C ) from the Japan Science and Technology Agency (JST) .
PY - 2014/2/1
Y1 - 2014/2/1
N2 - Biphasic calcium phosphate (BCP) consisting of hydroxyapatite (HAp) and β-tricalcium phosphate is usually prepared by thermal decomposition of calcium-deficient HAp (CDHAp). However, the calcium deficiency and morphology of CDHAp are difficult to manipulate in parallel. In this study, we report a novel strategy for controlling the composition of nanoporous BCP by using only CDHAp nanoparticles with specific properties (Ca/P molar ratio, 1.61; particle size, 50 nm) as a building block and by adjusting the calcium deficiency of the nanoparticle-assembled CDHAp (Ca/P molar ratio, 1.50-1.67; pore size, 8 nm) with the addition of water-soluble Ca(NO3)2 or (NH 4)2HPO4. After thermal treatment at 1000 C, the composition of BCP could be predictably controlled by adjusting the Ca/P ratio of the nanoparticle-assembled CDHAp. Changes in the Ca/P ratio did not significantly affect the surface morphology of BCP, but the grain size (210-300 nm) and pore size (140-170 nm) tended to increase slightly as the Ca/P ratio decreased. The porosity significantly decreased upon the addition of Ca salts (porosity, 20%) or PO4 salts (porosity, 14%) compared with that of the sample without additives (porosity, 53%). In vitro tests demonstrated enhanced cell adhesion on nanoporous BCP compared with densely sintered pure HAp, and cell differentiation was promoted on the nanoporous pure HAp.
AB - Biphasic calcium phosphate (BCP) consisting of hydroxyapatite (HAp) and β-tricalcium phosphate is usually prepared by thermal decomposition of calcium-deficient HAp (CDHAp). However, the calcium deficiency and morphology of CDHAp are difficult to manipulate in parallel. In this study, we report a novel strategy for controlling the composition of nanoporous BCP by using only CDHAp nanoparticles with specific properties (Ca/P molar ratio, 1.61; particle size, 50 nm) as a building block and by adjusting the calcium deficiency of the nanoparticle-assembled CDHAp (Ca/P molar ratio, 1.50-1.67; pore size, 8 nm) with the addition of water-soluble Ca(NO3)2 or (NH 4)2HPO4. After thermal treatment at 1000 C, the composition of BCP could be predictably controlled by adjusting the Ca/P ratio of the nanoparticle-assembled CDHAp. Changes in the Ca/P ratio did not significantly affect the surface morphology of BCP, but the grain size (210-300 nm) and pore size (140-170 nm) tended to increase slightly as the Ca/P ratio decreased. The porosity significantly decreased upon the addition of Ca salts (porosity, 20%) or PO4 salts (porosity, 14%) compared with that of the sample without additives (porosity, 53%). In vitro tests demonstrated enhanced cell adhesion on nanoporous BCP compared with densely sintered pure HAp, and cell differentiation was promoted on the nanoporous pure HAp.
KW - Assembly
KW - Calcium phosphate
KW - Nanoparticle
KW - Nanopore
KW - Osteoblast
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U2 - 10.1016/j.msec.2013.11.019
DO - 10.1016/j.msec.2013.11.019
M3 - Article
C2 - 24411377
AN - SCOPUS:84888988363
VL - 35
SP - 259
EP - 266
JO - Materials Science and Engineering C
JF - Materials Science and Engineering C
SN - 0928-4931
IS - 1
ER -