Hafeez Anwar

MRI based on iron oxide nanoparticles contrast agents: effect of oxidation state and architecture

AbstractIron oxide nanoparticles (IONPs) extensively employed beyond regenerative medicines to imaging disciplines because of their great constituents for magneto-responsive nano-systems. The unique superparamagnetic behavior makes IONPs very suitable for hyperthermia and imaging applications. From the last decade, versatile functionalization with surface capabilities, efficient contrast properties and biocompatibilities make IONPs an essential imaging contrast agent for magnetic resonance imaging (MRI). IONPs have shown signals for both longitudinal relaxation and transverse relaxation; therefore, negative contrast as well as dual contrast can be used for imaging in MRI. In the current review, we have focused on different oxidation state of iron oxides, i.e., magnetite, maghemite and hematite for their T1 and T2 contrast enhancement properties. We have also discussed different factors (synthesis protocols, biocompatibility, toxicity, architecture, etc.) that can affect the contrast properties of the IONPs. Graphical abstractᅟ

Synthesis, characterization, and pharmacological evaluation of zinc oxide nanoparticles formulation

Zinc oxide nanoparticles (ZnONPs) are being used extensively in manufacturing skin lotions and food products and in various biological and pharmaceutical industries because of their immunomodulatory and antimicrobial properties. In this study, ZnONPs were synthesized by a precipitation method and characterized by X-ray diffraction (XRD) techniques, scanning electron microscopy (SEM), and ultraviolet–visible spectroscopy to investigate their structural, morphological, and optical properties. For in vivo evaluation, 40 healthy albino mice were randomly allocated to four equal groups among which the first one was the control group, while the second, third, and fourth were treated with carbon tetrachloride (CCl4), a blend of CCl4 and ZnONPs, and ZnONPs alone, respectively, for 21 days. The XRD analysis confirmed hexagonal wurtzite type structures having an average crystallite size of 41.54 nm. The morphology of ZnONPs analyzed through SEM showed uniform distribution of the grains and shape of the synthesized oxide. The energy band gap of the ZnONPs was found to be 3.498 eV. Hepatic and renal damage following CCl4 administration was apparent after 14 days and was increased at the 21st day, showing nodular fibrotic masses in the liver and bumpy surfaces in the kidney as observed by gross and histological examination. Coadministration of ZnONPs (15 mg/kg b.w. intragastrically 5 days a week) significantly prevented the CCl4-dependent increases in alanine transaminase, aspartate transaminase, creatinine, and urea levels, suggesting a protective potential of ZnONPs.

Effect of ZnO on Photocatalytic Degradation of Rh B and Its Inhibition Activity for C. coli Bacteria

Zinc oxide (ZnO) nanoparticles have been synthesized by co-precipitation method. The structural properties like average crystallite size, lattice parameters, volume of unit cell, and X-ray density were studied by XRD. The crystallite size was measured by using Scherrer formula. It was observed that the average crystallite size increased with the increase of annealing temperature. Morphology of the synthesized oxides was investigated by SEM. The harmful constituents like organic compounds have been removed from waste water that is toxicant. Metal oxide semiconductors had shown good photocatalytic activity to degrade harmful organics into less harmful molecules under light-illumination. In this regard the dye (Rhodamine B) was degraded with increasing exposure time of UV radiations. Almost 60% dye degradation was observed in 150 min. The ZnO was also employed as an active anti-microbial nanomaterial on the growth of C. coli. A 15 μg of ZnO nanoparticles liquefied in 1 mL of dimethyl sulfoxide revealed outstanding 95.04 ± 1.37 % inhibition activities against growth of C. coli.

EXPRESS: Calibration-Free Laser-Induced Plasma Analysis of Nanoparticle-Doped Material Using Self-Absorption Correction Methodologies

The qualitative and quantitative analysis of doped nanomaterial containing iron (Fe) and tin (Sn) nanoparticles was investigated using laser-induced breakdown spectroscopy (LIBS). Doped nanoparticles were prepared via co-precipitation and hydrothermal processes. The emission spectra of ablated plasma of doped material revealed the existence of different species in the doped nanomaterial. Simple calibration-free LIBS (CF-LIBS) and internal reference self-absorption correction (IRSAC) CF-LIBS approaches were applied to emission spectra of nanomaterial for quantitative analysis. For both approaches, different spectroscopic parameters such as plasma temperature and electron number density were also determined. Plasma temperature was estimated using a Boltzmann plot and Saha–Boltzmann plot while electron number density was estimated by Stark broadening methods and Saha–Boltzmann equations. Results of both calibration-free approaches were compared with a weight percentage method and other recognized techniques such as laser ablation time of flight (LA-TOF) spectroscopy and energy dispersive X-ray (EDX). We concluded that our results provide good agreement with experimental data obtained using LA-TOF spectroscopy and a small deviation from data obtained using the EDX technique. The current work confirms LIBS as a valid analytical approach for quantitative analysis of nanomaterials.