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1.
Colloids Surf B Biointerfaces ; 228: 113423, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37390675

RESUMO

The novelty of this work is the conjugation of poly(ethylene) oxide (PEO) with the erbium oxide (Er2O3) nanoparticles using the electrospinning technique. In this work, synthesised PEO-coated Er2O3 nanofibres were characterised and evaluated for their cytotoxicity to assess their potential use as diagnostic nanofibres for magnetic resonance imaging (MRI). PEO has significantly impacted nanoparticle conductivity due to its lower ionic conductivity at room temperature. The findings showed that the surface roughness was improved over the nanofiller loading, implying an improvement in cell attachment. The release profile performed for drug-controlling purposes has demonstrated a stable release after 30 min. Cellular response in MCF-7 cells showed high biocompatibility of the synthesised nanofibres. The cytotoxicity assay results showed that the diagnostic nanofibres had excellent biocompatibility, indicating the feasibility for diagnosis purposes. With excellent contrast performance, the PEO-coated Er2O3 nanofibres developed novel T2 and T1-T2 dual-mode MRI diagnostic nanofibres leading to better cancer diagnosis. In conclusion, this work has demonstrated that the conjugation of PEO-coated Er2O3 nanofibres improved the surface modification of the Er2O3 nanoparticles as a potential diagnostic agent. Using PEO in this study as a carrier or polymer matrix significantly influenced the biocompatibility and internalisation efficiency of the Er2O3 nanoparticles without triggering any morphological changes after treatment. This work has suggested permissible concentrations of PEO-coated Er2O3 nanofibres for diagnostic uses.


Assuntos
Nanofibras , Polietilenoglicóis , Humanos , Polietilenoglicóis/metabolismo , Células MCF-7 , Óxidos , Imageamento por Ressonância Magnética , Etilenos
2.
Environ Sci Pollut Res Int ; 30(18): 52561-52575, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36829094

RESUMO

Developing and implementing visible light active organic-inorganic hybrid semiconductor nanomaterials with enhanced photocatalytic properties find newer environmental and energy treatment capabilities. Here, we are reporting polymeric g-C3N4 layers coated with different propositions of erbium oxide nanoparticles, characterized using XPS, UV-Vis-DRS, FT-IR, HR-TEM, FE-SEM, elemental mapping, XRD and surface area techniques and its photocatalytic activities were evaluated under visible light irradiations. The hybrid nanocomposite materials possess better crystalline nature and erbium oxide particles were on the surface of polymeric g-C3N4. The surface area and bandgap energy of the polymeric g-C3N4-erbium oxide (5 wt%) nanohybrid composite were 99.9 m2/g and 2.52 eV. The photocatalytic activities as prepared nanohybrid composites were assessed for the oxidation of orange G dye molecules in the presence of visible light and were highly active in a broader range of pH with the presence of various inorganic anions. The rate of photocatalytic oxidation of dye molecules varied from 4.79 × 10-4 to 1.77 × 10-4 min-1 for the initial concentration of 5 to 20 ppm and retained its activities above 95% up to three cycles of reusability. Hence, the organic-inorganic novel catalytic nanohybrid composite may find more comprehensive applications in the area of environmental and energy applications.


Assuntos
Luz , Óxidos , Espectroscopia de Infravermelho com Transformada de Fourier
3.
Biol Trace Elem Res ; 201(5): 2311-2318, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-35907160

RESUMO

Extensive uses of calcium titanate nanoparticles (CaTiO3-NPs) and erbium oxide nanoparticles (Er2O3-NPs) increase their release into the environment and human exposure, particularly through skin contact. However, there are almost no studies available on the effect of these nanoparticles on skin integrity. Therefore, this study was undertaken to estimate CaTiO3-NP- or Er2O3-NP-induced cytotoxicity and genotoxicity in normal human skin fibroblast (HSF) cells. Cell viability was measured using sulforhodamine B (SRB) assay, while the level of DNA damage was detected using the alkaline comet assay. The intracellular levels of reactive oxygen species (ROS) as well as the expression level of p53, Bax, and Bcl2 genes were detected. Although the viability of HSF cells was non-markedly changed after 24 h, prolonged treatment with CaTiO3-NPs or Er2O3-NPs for 72 h induced concentration-dependent death of HSF cells. Treatment of normal HSF cells with IC50/72 h of CaTiO3-NPs or Er2O3-NPs did not cause marked changes in the intracellular level of ROS, DNA damage parameters, and expression levels of apoptosis genes compared to their values in the untreated HSF cells. We thus concluded that CaTiO3-NPs or Er2O3-NPs cause time- and concentration-dependent cytotoxicity toward normal HSF cells. However, safe and non-genotoxic effects were demonstrated by the apparent non-significant changes in intracellular ROS level, DNA integrity, and apoptotic genes' expression after exposure of normal HSF cells to nanoparticles. Thus, it is recommended that further studies be conducted to further understand the toxic and biological effects of CaTiO3-NPs and Er2O3-NPs.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Humanos , Espécies Reativas de Oxigênio/metabolismo , Dano ao DNA , Nanopartículas/toxicidade , Sobrevivência Celular , Fibroblastos , Nanopartículas Metálicas/toxicidade , Estresse Oxidativo
4.
J Colloid Interface Sci ; 615: 69-78, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35124507

RESUMO

Engineering of electromagnetic wave absorbing materials featuring long-term durability in harsh outdoor environments (e.g., humidity, acid, and alkali conditions) is meaningful for their effective and sustainable implementation. Herein, morphology-controlled erbium oxide-reduced graphene oxide composites are designed for effective absorption of electromagnetic microwaves either in an acidic or alkaline environment. The engineered nanocomposites with chrysanthemum-like structures display good impedance matching, moderate attenuation constant, exchange resonance, natural resonance, multiple reflections, and polarization relaxations, therefore exhibiting excellent microwave absorption capacity with a minimum reflection loss of -37.18 dB and an effective absorption bandwidth of 5.1 GHz. In addition, the chrysanthemum-like composite also displays self-cleaning property, strong weatherability, and acid- and alkali-resistance, enabling sustained electromagnetic wave absorbing performance even in corrosive conditions (1 M HCl, 1 M NaOH). The findings indicate that, through structural engineering, erbium oxide-reduced graphene oxide composites can serve as a promising microwave absorber in harsh outdoor environments.


Assuntos
Micro-Ondas , Nanocompostos , Érbio , Grafite , Interações Hidrofóbicas e Hidrofílicas , Óxidos
5.
Spectrochim Acta A Mol Biomol Spectrosc ; 205: 341-347, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30032051

RESUMO

As a heavy rare earth oxide, erbium oxide (Er2O3) has many attractive properties. Monoclinic Er2O3 has useful properties not found in stable cubic Er2O3, such as unique optical properties and high radiation damage tolerance. In this study, pure cubic and mixed phase of cubic and monoclinic Er2O3 coatings were prepared. Photoluminescence properties of these coatings were characterized by a confocal micro-Raman spectrometer equipped with 325, 473, 514, 532, 633 nm lasers, and the influence of microstructure on the fluorescence properties was analyzed in detail. The room temperature fluorescence peaks of cubic Er2O3 were assigned. Furthermore, a novel method for rapid phase identification of Er3+ doped cubic and monoclinic rare earth sesquioxides at room temperature was proposed.

6.
J Res Natl Bur Stand (1977) ; 91(5): 243-253, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-34345084

RESUMO

This work describes the techniques used to prepare and analyze a reflectance wavelength standard composed of three rare-earth oxides. A mixture of dysprosium oxide (Dy2O3), erbium oxide (Er2O3), and holmium oxide (Ho2O3) provides a pressed powder specimen exhibiting a near infrared reflectance spectrum characterized by many discrete absorption minima in the wavelength range 700 to 2000 nm. The object of this activity was to develop a wavelength standard for improving the accuracy of reflectance measurements in the near infrared. The reflectance minima of the rare-earth oxide mixture was analyzed for the effects of varying spectral resolution and temperature. The uncertainties associated with the various parameters affecting the measurements and the determination of the location of the reflectance minima have been analyzed. The overall uncertainty in the location of these reflectance minima is believed not to exceed ± 1 nm.

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