Titanium dioxide nanoparticle absorbed by hepatoma cells in vitro

It is reported that nanoparticles can be applied as carriers and anti-cancer medicines. But the interaction of nanoparticles and cells is unclear. The purpose of this study was to discuss whether inorganic crystal nanoparticles can get through cells with intact crystal. BEL7402 hepatoma cells and titanium dioxide (TiO₂) nanoparticles were selected and incubated together in vitro. All specimens were prepared and observed under a transmission electron microscope (TEM). TiO₂ nanoparticles were found not in the nuclear area but in the cytoplasma. TiO₂ nanoparticles maintained the plate-like shape during absorbing. The result shows that hepatoma cells can endocytose the intact TiO₂ crystal nanoparticles. It implies that novel nano-effect plays an important role in the biomedicinal application of inorganic crystal nanoparticles. Funded by National Natural Science Foundation of China (No. 50472040)     

Selective Anti-Hepatoma Treated with Titanium Oxide Nanoparticles in vitro

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Surface analysis of chemical stripping titanium alloy oxide films

The chemical stripping method of titanium alloy oxide films was studied. An environment friendly solution hydrogen peroxide and sodium hydroxide without hydrofluoric acid or fluoride were used to strip the oxide films. The morphologies of the surface and cross-section of the oxide films before and after the films stripping were characterized by using scanning electron microscopy (SEM). The microstructure and chemical compositions of the oxide films before and after the films stripping were investigated by using Raman spectroscopy (Raman) and X-ray photoelectron spectroscopy (XPS). It was shown that the thickness of the oxide film was in the range of 5-6 μm. The oxide films were stripped for 2 to 8 min in the solution. Moreover, the effect of the stripping time on the efficiency of the film stripping was investigated, and the optimum stripping time was between 6-8 min. When the stripping solution completely dissolved the whole film, the α/β microstructure of the titanium alloy Ti-10V-2Fe-3Al was partly revealed. The stripping mechanism was discussed in terms of the dissolution of film delamination. The hydrogen peroxide had a significant effect on the dissolution of the titanium alloy anodic oxide film. The feasibility of the dissolution reaction also was evaluated.     

Magnetic biliary stent targeting to treat hepatoma combining with magnetic nanoparticles

To evaluate the effect of targeting to hepatoma treated by magnetic biliary stent combining with magnetic nanoparticle containing 5-fluorouracil （5-FU）, thirty-two nude mice modes with transplanted hepatoma were divided equally into four groups randomly. Experimental group received magnetic biliary stent and magnetic nanoparticles containing 5-FU. The tumor volume and pathomorphology of all groups was measured. The tumor control rate of the experimental group provided magnetic biliary stent wires and magnetic nanoparticles containing 5-FU is remarkably higher than three other control groups, showing significant curative effect. More apoptosis of tumor cells could be detected easily in experimental group. There are more apoptotic bodies and phagotrophic magnetic particle in apoptosis cells of experimental group under electron microscope. Magnetic biliary stent combining with magnetic nanoparticle containing 5-FU could inhibit the growth of hepatoma, and its curative effect is more remarkable than the traditional methods based on external magnetic fields.     

Fabrication and characterization of anodic oxide films on a Ti-10V-2Fe-3Al titanium alloy

Anodic oxide films of the titanium alloy Ti-10V-2Fe-3Al in ammonium tartrate electrolyte without hydrofluoric acid or fluoride were fabricated. The morphology,components,and microstructure of the films were characterized by scanning electron mi-croscopy(SEM) ,X-ray photoelectron spectroscopy(XPS) ,X-ray diffraction(XRD) ,and Raman spectroscopy. The results showed that the films were thick,uniform,and nontransparent. Such films exhibited sedimentary morphology,with a thickness of about 3 μm,and the pore diam...     

TC4钛合金表面氧化皮去除

针对TC4钛合金在热成形过程中其表面易形成一层致密的氧化皮且氧化皮的表面形貌和厚度均受温度影响这一现象,采用先热碱洗后酸洗的工艺过程对TC4钛合金在不同温度下氧化后的氧化皮去除工艺进行了研究.采用光学显微镜对氧化皮形貌进行表征,研究了时间对去除氧化皮的影响,且通过国际上较先进的美国LECO公司RH-404定氢仪对去除氧化皮后钛合金的氢质量分数进行了测定.结果表明,通过采用先热碱洗后酸洗的过程,TC4钛合金表面的氧化皮可以完全被去除.此外,通过RH-404定氢仪测得合金中氢质量分数的变化不大.     

Stepwise synthesis of cuprous oxide nanoparticles with adjustable structures and growth model

By stepwise adding of reducer N2H4·H2O,cuprous oxide(Cu2O)nanoparticles(NPs)with adjustable structures were synthesized.The features of Cu2O NPs were characterized by XRD,TEM and UV-Vis absorption spectra.When the reducer was added into the reactant system at one time,the sizes of the Cu2O NPs are in the range of 120–140 nm.Most Cu2O NPs are solid spheres.As the reducer was divided into two equal parts and stepwisely added,almost all the NPs are hollow spheres with good size(150–170 nm)distribution and dispersity.But when the reducer was divided into three or four equal parts and stepwisely added,the NPs are hollow spheres,core-shell structures or solid spheres,and the sizes distribution of the products is deteriorated.The effect of sodium hydrate(NaOH)was also probed.Addition of NaOH speeded up the nucleation and growth processes of Cu2O NPs.With the alkalinity increase,the shells of the hollow spheres become compact and the thicknesses of the shells increase,but the size distribution of the NPs is deteriorated.The absorption spectra of the Cu2O NPs are tunable.With the shell thicknesses increase,the absorption peaks have red shifts.An inside-outside growth model of Cu2O NPs was proposed to explain the results.The Cu2O single crystalline grains grow not only in the reactant solution,but also inside of the hollow nanospheres.The new Cu2O nanocrystallines can not only aggregate onto the shells of the nano hollow spheres,but also inside and outside of the hollow spheres,which leads to increasing the shell thicknesses of the hollow spheres,forming core-shell structures or small solid spheres of Cu2O NPs,respectively.     

Decorating multiwalled carbon nanotubes with zinc oxide nanoparticles by thermally decomposing Zn-oleate in an organic medium

Carbon nanotubes decorated with zinc oxide nanoparticles were produced by thermally decomposing a Zn-oleate complex in an octadecene medium. The structure of the ZnO decorating nanotube surfaces was characterized by transmission electron microscopy, scanning electron microscopy and X-ray diffraction. The surfaces were shown to be densely and homogeneously covered by ZnO nanoparticles with a size below 10 nm. The nanoparticles had the wurtzite hexagonal crystal structure and showed good adhesion to the nanotubes. The carbon nanotubes decorated by metal oxide nanoparticles were synthesized at relatively low temperature and non-oxidation environment. Moreover, the large-scale production with low cost can be realized.     

Characteristics of magnetic Fe3O4 nanoparticles encapsulated with human serum albumin

Magnetic nanoparticles （Fe304） were prepared by chemical precipitation method using Fe^2＋ and Fe^3＋ salts with sodium hydroxide in the nitrogen atmosphere. Fe3O4 nanoparticles were coated with human serum albumin（HSA） for magnetic resonance imaging as contrast agent. Characteristics of magnetic particles coated or uncoated were carried out using scanning electron microscopy and X-ray diffraction. Zeta potentials, package effects and distributions of colloid particles were measured to confirm the attachment of HSA on magnetic particles. Effects of Fe3O4 nanoparticles coated with HSA on magnetic resonance imaging were investigated with rats. The experimental results show that the adsorption of HSA on magnetic particles is very favorable to dispersing of magnetic Fe3O4 particles, while the sizes of Fe3O4 particles coated are related to the molar ratio of Fe3O4 to HSA. The diameters of the majority of particles coated are less than 100 nm. Fe3O4 nanoparticle coated with HSA has a good biocompatibility and low toxicity. This new contrast agent has some effects on the nuclear magnetic resonance imaging of liver and the lowest dosage is 20μmol/kg for the demands of diagnosis.