Synthesis and Characterization of Rutile TiO(2) Nanopowders Doped with Iron Ions.

Titanium dioxide nanopowders doped with different amounts of Fe ions were prepared by coprecipitation method. Obtained materials were characterized by structural (XRD), morphological (TEM and SEM), optical (UV/vis reflection and photoluminescence, and Raman), and analytical techniques (XPS and ICP-OES). XRD analysis revealed rutile crystalline phase for doped and undoped titanium dioxide obtained in the same manner.

Synthesis and characterization of sol-gel silica films doped with size-selected gold nanoparticles.

Homogeneous nanocomposite silica films uniformly doped with size-selected gold nanoparticles (AuNPs) have been prepared by a combined use of colloidal chemistry and the sol-gel process. For this purpose, stable thiol-functionalized AuNPs (DDT-AuNPs) were first synthesized by a two-phase aqueous/organic system and, subsequently, dispersed in an acid-catalysed sol-gel silica solution. The microstructural morphology of the samples was investigated by x-ray diffraction and field emission scanning electron microscopy.

TiO2 doped with nitrogen: synthesis and characterization.

In this study, nitrogen-doped titanium dioxide (TiO2) powders were synthesized in two ways: by heating of titanium hydroxide with urea and by direct hydrolysis of titanium tetraisopropoxide (TTIP) with ammonium hydroxide. The samples were characterized by structural (XRD), analytical (XPS), optical (UV/Vis absorption/reflection and Raman spectroscopy) and morphological (SEM, TEM) techniques. The characterization suggested that the doped materials have anatase crystalline form without any detectable peaks that correspond to dopants.

Growth of human endothelial cells on plasma-treated polyethyleneterephthalate surfaces.

Different methods have been proposed to reduce the surface thrombogenicity of small caliber vascular grafts, using plasma treatments of polymer surfaces in order to improve the adhesion and the proliferation of human endothelial cells (HEC). Plasma modified polyethyleneterephthalate (PET) substrates were employed to grow HEC, isolated from the umbilical vein. A combination of X-ray photoelectron spectroscopy (XPS) and Sessile contact angle (SCA) measurements allowed the study of the surface modifications produced soon after nitrogen and hydrogen plasma treatments with respect to an untreated PET substrate, used as reference.

Plasma-treated PET surfaces improve the biocompatibility of human endothelial cells.

Failures of small internal diameter vascular grafts have been caused by the lack of a stable endothelial lining to form on their artificial surfaces. Polymer surfaces can be optimized by means of proper treatment to allow a homogeneous and uniform coverage in artificial prosthesis applications. Several solutions were studied to improve cell attachment and growth on artificial materials.