Hydroxyapatite powder

According to Rolla, ionic bonds are important in the associations between bacterial polysaccharides and protein-coated tooth surfaces (21). This was based on in vitro experiments on the afiinity of dextran for hydroxyapatite powder coated with salivary glycoprotein specifically, adsorption of dextran was inhibited by 0.5M. Prior treatment of the coated hydroxyapatite with neuraminidase also reduced adsorption of dextran. Neuraminidase would be expected to reduce the negative charge of the protein coat by removing ionized sialic acid moieties. Of course, reduced adsorption of dextran could result from conformational changes induced in the pellicle protein by the neuraminidase treatment, as was apparently effected by 4M or 8M urea, in other experiments. 

Thomann, J.M., Voegel, J.C., and Gramain, Ph., Kinetics of dissolution of calcium hydroxyapatite powder. III. pH and sample conditioning effects. Calcif. Tissue Int., 46, 121, 1990. 

Penel, G. et al.. Infrared and Raman microspectrometry stndy in 11 nor-, lliiorhy-droxy-, and hydroxyapatite powders, J. Mater. Sci. Mater Med., 8, 271, 1997. 

Demnati, I., Grossin, D., Errassifi, F., Combes, C., Rey, C., and Le Boley, N. (2014a) Sythesis of fluor-hydroxyapatite powder for plasma sprayed biomedical coatings characterization and improvement of the powder properties. Powder Technol., 255, 23-28. 

Jaworski, R., Pierlot, C., Pawlowski, L., Bigan, M., and Martel, M. (2009b) Design of the synthesis of fine hydroxyapatite powder for suspension plasma spraying. Surf. Coat. Technol., 203 (15), 2092-2097. 

Figure 6.8 Spatial variation of the phase composition and the crystallinity of APS-HAp coatings incubated for 8 weeks in r-SBF (SBF-H, Table 7.8) as a function of the grain size of the precursor hydroxyapatite powder, (a) Coarse captal 90 powder (Plasma Coating...

Figure 7.21 Cathodoluminescence images of Mn2+-doped hydroxyapatite powder (top), an as-sprayed coating (a), and coatings incubated in r-SBF (SBF-H, Table 7.8) for 1 day (b),...

Han J-K., Song H-Y., et al. (2006). Synthesis of height purity nano-sized hydroxyapatite powder by microwave-hydrothermal method. Materials Chemistry and Physics, No. 99, pp 235 - 239... 

INFLUENCE OF THE HYDROXYAPATITE POWDER PROPERTIES ON ITS PROPERTIES RHEOLOGY BEHAVIOR... 

Influence of Hydroxyapatite Powder Properties on Its Properties Rheology Behavior... 

Hydroxyapatite powder used in this investigation was delivered from Riedel-de Haen Co. (Seelze, Germany). A stock of HA powder was firstly calcined at both 1000 and 1100°C. The various properties of both as received and calcmed powders were shown in Table. 1. 

U.C. Knowles, S. Calcut, G. Georgiou, Characterization of therheological properties and zeta potential of a range of hydroxyapatite powders. Biomaterials, 21, 1387-1392 (2000). 

D. Bayraktar and A. C. Tas, Chemical Preparadon of Carbonated Calcium Hydroxyapatite Powders at 37°C in Urea-containing Synthetic Body Fluids, J. Eur. Ceram. Soc., 19, 2573-9 (1999). 

A. C. Tas, Synthesis of Biomimetic Ca-Hydroxyapatite Powders at 37C in Synthetic Body Fluids, Biomaterials, 21,1429-38 (2000). 

Kim IS, Kumta PN. Sol-gel synthesis and characterization of nanostructured hydroxyapatite powder. Mater Sci Eng B-Solid 2004 111 232-6. 

Microscale hydroxyapatite (size distribution of the powder 3.0 0.1 J,m) similar to the innate hydroxyapatite in human bone (57.0 and 41.4 wt% of CaO and P2O5, respectively Ca/P molar ratio 1.67) was used to fabricate films after suspension in solutions of 400 kDa chitosan. Becanse of the well-dispersed hydroxyapatite powders in the polymer matrix, the film appeared white and flexible with a transmittance <20% in the visible range. The observation under the SEM ensnred monodis-persity of the films. Good monodispersity improved the homogeneity and uniformity of the film, and prevented phase separation resulting in unwanted microcracks (Kim et al. 2009). 

---