International Journal of Nanoscience

In the present work, nanocrystalline hausmannite Mn₃O₄:Ba thin films have been deposited on glass substrates by chemical spray pyrolysis (CSP). Then, we investigated the impact of Ba doping concentrations on the structural, morphological and optical properties. The structural characteristics were investigated by X-ray diffraction technique and clearly show the films have a spinel Mn₃O₄ polycrystalline structure, the degree of crystallinity was improved by increasing Ba concentrations in Mn₃O₄ matrix with crystallite size range of 15–33nm. The lattice parameters, the unit cell volume and the (Mn-O) bond length of tetrahedral and octahedral sites, were varied by increasing Ba concentrations. SEM micrographs show that the films are homogeneous with nanoparticles dispersed on the surface with sizes range 30–132nm. The optical properties were estimated by UV-Vis-NIR spectrophotometer and exhibited that the optical transmittance and band gap were improved by increasing Ba doping concentration. Empirical equations were suggested to estimate some correlated variables with excellent agreement with the experimental data. The optimum condition was recorded in films doped with 3% of Ba where a better crystallinity, a preferable surface morphology and outstanding optical properties have been achieved.

Nanotechnology is a favorable avenue for improving therapeutic strategies, especially in cancer therapy. The harmful side effects of traditional cancer therapy impact dramatically on the patient’s quality of life. Cisplatin, a commonly used anticancer drug, is implicated in side effects such as neurotoxicity, nephrotoxicity and reduced blood cell count. Silver nanoparticles (AgNPs) have been investigated for their antibacterial effects and their anticancer activities to a lesser extent. Their capability as drug delivery vehicles has not been fully exploited, primarily due to their inconclusive cytotoxicity observed in healthy tissues. This study aimed to synthesize and characterize nanoparticles (NPs), consisting of Ag, chitosan (Cs) and folic acid (FA) (CsAg and FACsAg), loading them with cisplatin (C) (C-CsAg and C-FACsAg) and comparing their anticancer activities in the human embryonic kidney (HEK293), breast adenocarcinoma (MCF-7) and cervical carcinoma (HeLa) cells. All NPs and drug nanocomplexes were morphologically and physicochemically characterized, revealing NPs and nanocomplexes of favorable sizes ($<110$nm), polydispersity and stability. The drug encapsulation efficiencies for C-CsAg and C-FACsAg were 50% and 72%, respectively, while drug release studies indicated that cisplatin release was pH dependent. The C-FACsAg nanocomplexes produced greater anticancer activity than C-CsAg. Folate receptor-mediated uptake was confirmed for the C-FACsAg nanocomplexes in the receptor-rich HeLa cells boding well for future in vivo research.

Pure and “Fe ($\sim 3$wt.%)-doped” WO${}_{3-x}$ nanoparticles were prepared by facile microwave irradiation method and that was investigated for strong photo catalytic and antibacterial activity applications for the first time. The primary aim of this work is to reveal the great importance of oxygen vacancies ($V_0)$ due to dopant (Fe${}^{2+})$ for photo catalytic and antibacterial activity applications. This work also discusses the contribution of oxygen vacancies and their dependence on surface area and phase formation which are of great research interest for water purification and biological sciences. Herein, pure and “Fe ($\sim 3$wt.%)-doped” WO${}_{3-x}$ nanoparticles were successfully synthesized by facile microwave irradiation (MWI) method (2.45 GHz/240W/10min) in ambient atmosphere. The phase formation and the crystalline nature of the prepared products were evaluated using powder X-ray diffraction (XRD). It confirmed the phase formation of orthorhombic and monoclinic phase formations for the pure (WO${}_3\cdot$H₂O) and annealed samples (W${}_{17}$O${}_{47}$ and WO${}_3)$, respectively. Optical behavior of the samples from UV-Vis diffuse reflectance analysis revealed that W${}_{17}$O${}_{47}$ has remarkable bandgap values (1.96eV) that clearly emphasizes the transfer of oxygen ions which helps in the movement of oxygen vacancies inside the crystalline domain. The morphological nature of the prepared products was observed by FE-SEM analysis and the average dimension was found to be 0.2–3.2$\mu$m and 2–4$\mu$m for the pure and annealed products, respectively. The specific surface area from BET analysis explored that W${}_{17}$O${}_{47}$ having 55.16m²g${}^{-1}$ was found to be higher than that of commercially available WO₃. The photocatalytic behavior of the prepared compounds morphologies was investigated via Rhodamine B (RhB) degradation under visible light irradiation. These results showed “Fe-doped” annealed WO₃ nanoparticles have degradation efficiency of 86.9% along with high stable nature. On the other hand, to identify the suitability of the prepared products for antibacterial activity, the microbial strains of Gram-positive Bacillus sp. and Gram-negative strains of Pseudomonassp. and Salmonellasp. were used for the antimicrobial assay$.$ The results indicated that W${}_{17}$O${}_{47}$ showed enhanced antibacterial nature when compared to that of Stoichiometry tungsten oxide (WO${}_3)$ nanomaterials. From these observations, this work emphasizes the importance of oxygen vacancies for antibacterial activity applications.

Silver nanoparticles (AgNPs) have been synthesized by chemical reduction method using ascorbic acid as reducing agent. Silver nitrate (AgNO${}_3)$ and sodium dodecyl sulfate (SDS) have been used as precursor and stabilizer, respectively. The prepared samples were characterized by UV-visible spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The antibacterial activity of prepared silver nanoparticles has been assessed by using the disc diffusion method against pathogenic, gram-negative bacterial strains including Escherichia coli and Pseudomonassp. To evaluate the potential antibacterial properties of AgNPs, the discs have been impregnated and dried with three different doses like 50, 100 and 150$\mu$l of 20$\mu$g/ml concentrated AgNPs solution and placed on the Petri-dishes. The antibiotic kanamycin (5$\mu$g) was used as control. In all the cases, a clear and distinct zone of inhibition is observed, which suggests that AgNPs can be used as effective growth inhibitors of various bacterial species and would be promising candidate for future development of antibacterial agents.

This paper investigates the spectroscopy of plasma that resulted from the bombardment of ZnSe by using the optical emission spectroscopic (OES) technique. The plasma can be generated by the reaction between an Nd:YAG laser, with a wavelength of 1064nm with a repeat rate of 6Hz (as well as 9ns pulse duration), and a solid target, where the density of the electron (ne), the temperature of the electron ($T_e$), the frequency of the plasma ($f_P$) and the Debye length (${\lambda }_D$) as plasma parameters, in addition to the particles’ number of Debye ($N_D$) and plasma parameter ($\mathrm{\Lambda }$) have been calculated by picking up the spectrum of plasma at different energies (100, 200, 300, 400, 500) mj using Selenium (Se), Zinc (Zn) and the mixture (ZnSe) at ($X=0.5$). It is found that the electron temperatures of Zn and Se ranged between (0.257–0.267)eV and (1.036–1.055) eV, respectively, while that of ZnSe ranged between (1.15–1.28)eV. This indicates that the electron temperature of ZnSe is higher than the temperatures of each Zn and Se.

g-C₃N₄@WO₃.H₂O nanoplate composite adsorbents were prepared in a simple acid precipitation method at room temperature. The g-C₃N₄@WO₃.H₂O nanoplate composite adsorbents were characterized by X-ray powder diffraction, micro-Raman spectroscopy, Fourier transform infrared spectra, scanning electron microscopy and UV-vis diffuse reflectance spectroscopy. The results show that the orthorhombic-phase WO₃.H₂O nanoplates with dimensions of $\sim 200\times 150\times 40$nm³ were successfully composited with g-C₃N₄. The methylene blue dye generation activity of these adsorbents was evaluated. The kinetics and absorption model of g-C₃N₄@WO₃.H₂O nanoplate composite adsorbents were further studied.

This research aims to study the addition of nanoclays on unsaturated polyester (UP) and epoxy resin (EP) as filling and by weight percentage (2%, 4% and 6%) to this mixture and then study the extent of the effect of this addition on wear rate of the composites’ material where three loads were adopted (10, 15 and 20N), respectively, on the iron hard disk (269 HB) and copper hard disk of 111HB for the resin before and after adding the clays, where the approved sliding velocities were 4.1887, 3.1415 and 2.0943m/sec, respectively, and the test duration was 10 min on the test disc. Immersion of samples in the water for 2, 4, 6 and 8 weeks showed a clear improvement in the wear rate and tear values of dry and submerged conditions in a water under different conditions of load change, slipping speed, time and temperature stability after adding the nanoclays to the polymer.

NiFe₂O₄ magnetic nanoparticles (MNPs) were synthesized by co-precipitation of iron (III) chloride hexahydrate and nickel (II) chloride hexahydrate in the solution containing 45% hydrazine at 80^∘C. Phase, morphology, oxidation state and magnetic properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometry (VSM). In this research, pure NiFe₂O₄ MNPs synthesized in the solution with the pH of 10 with saturation magnetization of 49.839emu/g were detected and were able to be used for magnetic resonance imaging (MRI) application with very high contrast.

Highlights: $▸$ NiFe₂O₄ is used as magnetic nanoparticles. $▸$ They have an excellent saturation magnetization. $▸$ The promising material is used for magnetic resonance imaging application.

Recently, pollen grains (PGs) have been introduced as drug carriers and scaffolding building blocks. This study aimed to assess the in-vitro biocompatibility of Pistacia vera L. hollow PGs/Fe₃O₄ nanoparticles (HPGs/Fe₃O₄NPs) composites using human adipose-derived mesenchymal stem cells (hAD-MSCs). In this regard, iron oxide nanoparticles (Fe₃O₄NPs) were assembled on the surface of HPGs at different concentrations. The biocompatibility of the prepared composites was assessed through MTT assay, apoptosis-related gene expression and field emission scanning electron microscopy (FE-SEM) analysis. Compared to the bare HPGs, the HPGs/Fe₃O₄NPs exhibited a biphasic impact on hAD-MSCs. The composite containing 1% Fe₃O₄NPs demonstrated no cytotoxicity up to 21 days while higher Fe₃O₄NPs contents and long-term exposure revealed adverse effects on the hAD-MSCs’ growth. The obtained result was verified by the qRT-PCR and morphological analysis carried out through FE-SEM which suggests that a narrow region below 1% Fe₃O₄NPs may be the optimum choice for medicinal applications of HPGs/Fe₃O₄NPs microdevices.

Improving permeability and absorption of drugs are critical research challenges in pharmaceutical science. Gentamicin sulfate is an aminoglycoside antibiotic, which is very active against gram-negative bacteria; however, it has very poor bioavailability. This study aimed to prepare gentamicin nanoparticles with the intention of increased bioavailability. Accordingly, Eudragit RS-100 nanoparticles loaded with gentamicin sulfate were prepared by the double emulsification and solvent evaporation method, a proper technique for encapsulating hydrophilic molecules. Nanoparticles’ suspensions with polymer to drug ratios of 1:1 ($F_a)$ and 2:1 ($F_b$) were prepared, lyophilized and evaluated for their production yield, physicochemical properties and morphology. The mean particle size was 195.67nm and 228nm for $F_a$ and $F_b$, respectively. The formulations’ loading efficiencies were relatively high (85.73 for $F_a$ and 85.20 for $F_b$). The nanoparticles’ surface charge (+40.5mV) was sufficient to inhibit their aggregation and facilitate the nanoparticles’ absorption through the gastrointestinal tract. The results of differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) revealed that drug and polymer stabilized each other by physical interactions between their functional groups. Both formulations presented an initial burst drug release of nearly 20% after 30min in phosphate buffer (pH = 7.4). After 24h, $F_b$ did not release the drug completely, while $F_a$ released the whole drug. Overall, nanoparticles with proper characteristics were obtained. This study puts forward the necessity of conducting further research in order to explore the intestinal absorption of these nanoparticles and the possibility of being utilized for oral administration of gentamicin sulfate.