A novel strategy for preparing nanoporous biphasic calcium phosphate of controlled composition via a modified nanoparticle-assembly method

Keiko Fujiwara, Masahiro Okada, Shoji Takeda, Naoyuki Matsumoto

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)259-266
Number of pages8
JournalMaterials Science and Engineering C
Volume35
Issue number1
DOIs
Publication statusPublished - Feb 1 2014
Externally publishedYes

Keywords

  • Assembly
  • Calcium phosphate
  • Nanoparticle
  • Nanopore
  • Osteoblast

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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