l-Cysteine-Conjugated Ruthenium Hydrous Oxide Nanomaterials with Anticancer Active Application.

Bioactive nanomaterials, namely: ruthenium hydrous oxide (or ruthenium oxy-hydroxide), RuOx(OH)y and also a surface-conjugated novel material of the same within the template of an amino acid molecule, l-cysteine, have been studied. These compounds have been prepared through a simple wet chemical route, under physiological conditions, such that they could be suitably used in anticancer applications. Several physical methods were used for the nanomaterial characterization, e.g.: thermal analysis of the as prepared ruthenium hydrous oxide by differential scanning calorimetry (DSC) followed by thermal gravimetric analysis (TGA). This confirms that the material is a precursor for anhydrous nanocrystalline ruthenium oxide (RuO2), as is affirmed by powder X-ray diffraction pattern. Also, optical spectroscopic absorption (UV-vis and FT-IR) study of these nanoparticles (NPs) to ascertain their surface conjugation with l-cysteine have been performed. Besides these, surface morphology of the NPs were studied by field emission scanning electron microscopy (FE-SEM) along with their elemental purity check through energy dispersive X-ray analysis (EDX). Their surface chemical microenvironments were examined by X-ray photo electron spectroscopy (XPS). The hydrodynamic size of the prepared NPs were measured through dynamic light scattering (DLS) studies. Further, biological consequences of these NPs on cancerous HeLa cells and their cytotoxicity effects have been reported with MTT assay, such an application has not been reported so far.

Study of Gallium Oxide Nanoparticles Conjugated with ß-Cyclodextrin: An Application To Combat Cancer.

Bioactive nanomaterials, namely, gallium oxyhydroxide GaO(OH), also surface-conjugated GaO(OH) with a giant sugar molecule ß-cyclodextrin (CD), have been prepared through a simple wet chemical route such that the same could be suitably used in biomedical diagnostics as well as therapeutic applications. Several physical methods were used for their characterization: powder X-ray diffraction pattern of GaO(OH) NPs for their grain size determination, optical spectroscopic absorption (UV-vis and FT-IR), and fluorescence properties of these NPs to ascertain surface conjugation and also their wide band-gap properties. Besides these, morphological properties of these NPs were studied by transmission electron microscopic (TEM) investigation, justifying the elemental constitution through energy dispersive X-ray analysis (EDX). Further, biological cellular uptake of these nanoparticles have been demonstrated on cancerous HeLa cells and reported with total fetal effect after 72 h, with CD templated GaO(OH) nanoparticles, a fact that has not been reported so far.

Characterization of ZnO nanoparticles grown in presence of folic acid template.

BACKGROUND: ZnO nanoparticles (grown in the template of folic acid) are biologically useful, luminescent material. It can be used for multifunctional purposes, e.g., as biosensor, bioimaging, targeted drug delivery and as growth promoting medicine. METHODS: Sol-gel chemical method was used to develop the uniform ZnO nanoparticles, in a folic acid template at room temperature and pH ~ 7.5. Agglomeration of the particles was prevented due to surface charge density of folic acid in the medium. ZnO nanoparticle was further characterized by different physical methods. RESULTS: Nanocrystalline, wurtzite ZnO particles thus prepared show interesting structural as well as band gap properties due to capping with folic acid. CONCLUSIONS: A rapid, easy and chemical preparative method for the growth of ZnO nanoparticles with important surface physical properties is discussed. Emphatically, after capping with folic acid, its photoluminescence properties are in the visible region. Therefore, the same can be used for monitoring local environmental properties of biosystems.

Surface modification of mica due to titanium sputtering as studied by positron annihilation.

Study was conducted of surface structural modification of layered sheets of mica that had been subjected to titanium (Ti) sputter coating, use being made of a variable but mono energetic slow positron beam. Comparison has been drawn with the structure of pure muscovite mica sheet. Doppler broadening (DB) of the energy of annihilation radiation has been used as a parameter to assay changes in the surface characteristics within a depth profile of 500 angstroms. In support of these investigations, X-ray reflectivity data was used to assay titanium film thickness and the electron density profile of the film on mica. Finally, changes involving the surface micro-morphology of the system have been corroborated by scanning electron microscopy.

Effect of temperature on positronium annihilation in silica gel.

A systematic temperature-dependent study of positronium annihilation rate within the void spaces (micro- and mesopores) of silica gel material has been performed through positronium annihilation spectroscopy. The results find their plausible interpretation through a novel theoretical explanation based on vibrational interaction of thermally energized atoms on the surface layer of the pores with positronium, which in fact justifies the observed increase in the annihilation rate of the latter, with the increase in temperature.