Preparation and Characterization of Hydroxyapatite Particles Having Hydrophobic Surface

Phosphorus Research Bulletin

Hino

et al. 2006

Self Cite

Hydroxyapatite (HAP) was prepared from CaCl 2 , Na 2 HPO 4 and NaOH in an aqueous phase mixed with a chloroform solution of cetylphosphate (CP). The CP was incorporated mainly on the surface of HAP but not to its bulk phase, resulting in formation of a hydrophobic surface. This surface-modified HAP has various characteristic properties different from those of the intact HAP. Some of the examples are as follows; an increase in a contact angle of water droplet, a decrease in a mean diameter of the HAP particle, and increases in the amounts of adsorption of various organic compounds. The aim of this study was of characterization of the surface-modified HAP through determining the adsorption amounts of various organic compounds on the surface. As for the adsorption of a surfactant to the modified HAP, it was concluded that hydrophobic interaction between alkyl chains of a surfactant and those of CP implanted on the surface became more important than hydrophilic interaction between polar/ionic groups of a surfactant and ions exposed on the intact area of the HAP. In the adsorption of bovine serum albumin (BSA), it was denatured by the CP implanted on the surface of the modified HAP (i.e., surface denaturation). Adsorption properties of the surface-modified HAP were quite different from those of the intact HAP.

Section: Introductionmentioning

confidence: 85%

Preparation and Adsorption Properties of Hydroxyapatite Surface-Modified by Cetylphosphate

Warabino

Phosphorus Research Bulletin

Hino

et al. 2006

Self Cite

“…The HAP nanoparticles, of which surface was modified for CLSM measurement, were prepared by a method mentioned elsewhere 26 . To put it briefly, Hap was carried out by treating the 100 mg of Hap nanoparticles in Tris -HCl buffer (10 mM pH 7.40) solutions containing rhodamine labeled opea (0.5 x 10 -4 mol/l) at room temperature for 3 day.…”

Section: Surface Modification For Hapmentioning

confidence: 99%

Formation of Poly-L-Arginine - Hydroxyapatite Nanoparticle Complexes and Interactions Between Complexes and Lipidbilayer Membranes.

Phosphorus Research Bulletin

Shimabayashi

2009

Self Cite

A certain molecule permeable to a phospholipid bilayer membranes (cell or endosormal membrane) is a useful carrier (i.e. vector) for drugs (especially polymeric drugs). We prepared two types of the hydroxyapatite nanoparticlepoly-L-arginine complexes in a different solvent, which were used as the probes for the study on the translocationability through the negatively charged phospholipid bilayer membranes by means of a confocal laser scanning microscope (CLSM). CLSM observation and secondary structure of poly-L-arginine moieties which estimated by FT-IR measurement showed the transformation of the polypeptide secondary structure on the surface of liposome is on important key step of membrane transfer of the these complexes.

“…The HAP nanoparticles, of which surface was modified, were prepared by a method mentioned elsewhere [27]. To put it briefly, Hap was carried out by treating the 100 mg of Hap nanoparticles in Tris-HCl buffer (10 mM pH 7.40) solutions containing rhodamine labeled opea (0.5 × 10 −4 mol/l) at room temperature for 3 days.…”

Section: Surface Modification For Hap and Complex Formationmentioning

confidence: 99%

Poly-L-arginine–hydroxyapatite nanoparticle complexes translocate through lipidbilayer membranes

Bio-Medical Materials and Engineering

Shimabayashi²

2009

Self Cite

Certain molecules, which are able to directly translocate across phospholipid bilayer membranes (cell or endosormal membrane), can be useful as carriers (vectors) for drags (especially polymeric drags). We have studied the translocationability of the hydroxyapatite nanoparticle-poly-L-arginine complex through the negatively charged phospholipid bilayer membranes by using several instruments. It was confirmed by means of a confocal laser scanning microscopy (CLSM) not only the fact that the complex can translocate through the membranes but also the fact that the complexes were still retained in the inner water layer of the liposome even after the translocation.