Bone-like Layer Growth and Adhesion of Osteoblast-like Cells on Calcium-deficient Hydroxyapatite Synthesized at Different pH

Abstract

Calcium-deficient hydroxyapatite (DAp) was synthesized by hydrolysis of -TCP at different pH. Ca/P ratio of DAp increased with increasing pH during the hydrolysis. In addition, DAp which was synthesized at lower pH, showed higher solubility in the simulated body fluid (SBF) and had a more negatively charged surface than that at higher pH. Bone-like crystals were formed on DAp which have been soaked in SBF at 309.5 K in vitro. DAp demonstrated faster formation of a bone-like layer than stoichiometric hydroxyapatite (HAp). Moreover, the formation of the crystals on DAp synthesized at lower pH was much faster than that at higher pH. The adhesion of MC3T3-E1 osteoblast-like cells was also influenced by pH during the synthesis of DAp; the number of adhering cells increased with a decrease in the pH. Therefore, high solubility and negative charge of DAp, especially that synthesized at lower pH resulted in fast formation of bone-like crystals and good cell adhesion.

Induction suspension plasma sprayed biological-like hydroxyapatite coatings

“…Ca concentration decreases over time, starting in the first week and indicating a phase of significant precipitation. As reported in the literature, 88,89 dissolution is predominant during the first hours of immersion, which is probably why no Ca increase was observed in our experiment after one week. After six weeks of immersion, Ca ion concentrations in SBF for as-sprayed samples seemed to increase slightly and then decrease again after eight weeks.…”

Texture Control in Hydroxyapatite by Hot Forging

“…11,12) -TCP powder was stirred in distilled water at 353 K for 3 h. The pH value of the suspension was kept constant at 8.5 by adding ammonium solution. Thereafter, DAp powder in the suspension was separated by filtration and dried at 373 K. A schematic illustration of the colloidal process is shown in Fig.…”

“…11,12) The aspect ratio of DAp prepared in the present study is high since it was prepared at pH ¼ 8:5.…”

Effect of Milling Treatment on Texture Development of Hydroxyapatite Ceramics by Slip Casting in High Magnetic Field

“…[1][2][3][4] Many studies on HAP for artificial bones and implants have been conducted. 4,5) HAP is an ionic crystal that has a hexagonal structure with the space group P6 3 /m. The lower crystallographic symmetry induces mechanical anisotropy along each axis.…”