The True Nature of Tricalcium Phosphate Used as Food Additive (E341(iii)).

Tricalcium phosphate (TCP) is a food additive, labeled E341(iii), used in powdered food preparation, such as baby formula. In the United States, calcium phosphate nano-objects were identified in baby formula extractions. Our goal is to determine whether the TCP food additive, as is used in Europe, can be classified as a nanomaterial.

Polyaniline photoluminescence quenching induced by single-walled carbon nanotubes enriched in metallic and semiconducting tubes.

The influence of single-walled carbon nanotubes enriched in semiconductor (S-SWNTs) and metallic (M-SWNTs) tubes on the photoluminescence (PL) of polyaniline (PANI), electrosynthesized in the presence of the HSO and HCl solutions, is reported. The emission bands peaked at 407-418 and 440-520 nm indicate that the electropolymerization of aniline (ANI) leads to the formation of short and longer macromolecular chains (MCs), respectively. We demonstrate that the reaction product consists of ANI tetramers (TT) and trimers (TR) as well as PANI-salt.

Polarized infrared reflectance spectra of brushite (CaHPO4·2H2O) crystal investigation of the phosphate stretching modes.

Polarized infrared (IR) reflectance measurements at near-normal incidence were recorded from the ac-plane of a monoclinic brushite (CaHPO4·2H2O) crystal in the 800-1200 cm(-1) spectral range (P-O stretching modes). The adjustment of these data, on the basis of a dispersion analysis (DA) model for monoclinic case, allowed the determination of oscillators parameters for the four P-O stretching observed modes of the phosphate group.

Effects of citrate and NaCl on size, morphology, crystallinity and microstructure of calcium phosphates obtained from aqueous solutions at acidic or near-neutral pH.

Precipitation of calcium phosphates occurs in dairy products and depending on pH and ionic environment, several salts with different crystallinity can form. The present study aimed to investigate the effects of NaCl and citrate on the characteristics of precipitates obtained from model solutions of calcium phosphate at pH 6·70 maintained constant or left to drift. The ion speciation calculations showed that all the starting solutions were supersaturated with respect to dicalcium phosphate dihydrate (DCPD), octacalcium phosphate (OCP) and hydroxyapatite (HAP) in the order HAP>OCP>DCPD.

Characterization and properties of novel gallium-doped calcium phosphate ceramics.

Addition of a gallium (Ga) precursor in the typical reaction protocols used for the preparation of β-tricalcium phosphate (β-TCP) led to novel Ga-doped β-TCP ceramics with rhombohedral structures (R3c space group). From the refinement of their X-ray diffraction patterns, it was found that the incorporation of Ga in the β-TCP network occurs by substitution of one of the five calcium (Ca) sites, while occupation of another Ca site decreases in inverse proportion to the Ga content in the structure. The Ga local environment and the modification of the phosphorus environments due to the Ga/Ca substitution in Ga-doped β-TCP compounds are probed using (31)P and (71)Ga magic-angle spinning NMR.

Na-doped β-tricalcium phosphate: physico-chemical and in vitro biological properties.

Synthetic calcium phosphate ceramics as β-tricalcium phosphate (Ca(3)(PO(4))(2); β-TCP) are currently successfully used in human bone surgery. The aim of this work was to evaluate the influence of the presence of sodium ion in β-TCP on its mechanical and biological properties. Five Na-doped-β-TCP [Ca(10.

The in vivo degradation of a ruthenium labelled polysaccharide-based hydrogel for bone tissue engineering.

In this paper we report a new method that permitted for the first time to selectively track a polysaccharide-based hydrogel on bone tissue explants, several weeks after its implantation. The hydrogel, which was developed for bone healing and tissue engineering, was labelled with a ruthenium complex and implanted into rabbit bone defects in order to investigate its in vivo degradation. 1, 2, 3 and 8 weeks after surgery, the bone explants were analyzed by synchrotron X-ray microfluorescence, infrared mapping spectroscopy, scanning electron microscopy, and optical microscopy after histological coloration.

Rapid prototyped porous titanium coated with calcium phosphate as a scaffold for bone tissue engineering.

High strength porous scaffolds and mesenchymal stem cells are required for bone tissue engineering applications. Porous titanium scaffolds (TiS) with a regular array of interconnected pores of 1000 microm in diameter and a porosity of 50% were produced using a rapid prototyping technique. A calcium phosphate (CaP) coating was applied to these titanium (Ti) scaffolds with an electrodeposition method.

The rheological properties of silated hydroxypropylmethylcellulose tissue engineering matrices.

This paper describes the rheological properties of silated hydroxypropylmethylcellulose (HPMC-Si) used in biomaterials domain as a three-dimensional synthetic matrix for tissue engineering. The HPMC-Si is an HPMC grafted with 3-glycidoxypropyltrimethoxysilane (GPTMS). HPMC and HPMC-Si were studied.

Enhanced expression of the inorganic phosphate transporter Pit-1 is involved in BMP-2-induced matrix mineralization in osteoblast-like cells.

Unlabelled: Pi handling by osteogenic cells is important for bone mineralization. The role of Pi transport in BMP-2-induced matrix calcification was studied. BMP-2 enhances Pit-1 Pi transporters in osteogenic cells.