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SOD-like activity of CeO2 nanoparticles (Ce NPs) is driven by Ce3+/Ce4+, high oxidative stress can oxidize Ce3+ to reduce the ratio of Ce3+/Ce4+, inactivating the SOD activity of Ce NPs. Herein, we found Au@Ce NPs, assembled by Au NPs and Ce NPs, exhibited high-performance of SOD mimetic enzyme activity even upon the oxidation of H2O2. Ce NPs supported by nano-Au can acquire the electrons from Au NPs through the enhanced localized surface plasmon resonance (LSPR), maintaining the stability of Ce3+/Ce4+ and SOD-like activity. Meanwhile, Au@Ce NPs retained the peroxidase function and catalase function. As a result, Au@Ce NPs effectively scavenged O2•- and the derived ROS in AML cells, which are the important signaling source that drives AML cell proliferation and accelerates cell cycle progression. When HL-60 cells were treated by Au@Ce NPs, the removal of endogenous ROS signal significantly arrested cell cycle at G1 phase and suppressed the cell proliferation by blocking the mitogen-activated protein kinases (MAPKs) signaling and the Akt/Cyclin D1 cell cycle signaling. Importantly, this treatment strategy showed therapeutic effect for subcutaneous transplantation of AML model as well as a satisfactory result in diminishing the leukocyte infiltration of liver and spleen particularly. Thus, assembled Au@Ce NPs show the high-performance SOD-like activity, promising the potential in treating AML and regulating abnormal ROS in other diseases safely and efficiently., Graphical abstract Au@CeO2 NPs, assembled by Au NPs and CeO2 NPs, eliminated ROS signaling and arrested cell cycle and proliferation through its high-performance SOD activity and the relay conversion of O2•- →H2O2→O2. (i) Schematic of CeO2 NPs SOD activity that was suppressed by the oxidation of H2O2. (ii) Schematic of Au@CeO2 NPs SOD activity that can maintain the stability against the oxidation of H2O2 according to the electron compensation effect from Au substrate.Image 1, Highlights • Assembled Au@Ce NPs exhibited multi-enzyme activity and the high-performance SOD-like activity even upon the oxidation of H2O2. • In the assembled Au@Ce NPs, Ce NPs can acquire the electrons from Au NPs to maintain the stability of Ce3+/Ce4+ and SOD activity. • Au@Ce can scavenge O2•- and the derived ROS in AML cells to arrest cell cycle signal and proliferation signal. • Au@Ce treatment suppressed the growth of HL-60 bearing tumors and prolonged the survival time in systemic AML mice.

Bone regeneration is a crucial part in the treatment of periodontal tissue regeneration, in which new attempts come out along with the development of nanomaterials. Herein, the effect of cerium oxide nanoparticles (CeO2 NPs) on the cell behavior and function of human periodontal ligament stem cells (hPDLSCs) was investigated. Results of CCK-8 and cell cycle tests demonstrated that CeO2 NPs not only had good biocompatibility, but also promoted cell proliferation. Furthermore, the levels of alkaline phosphatase activity, mineralized nodule formation and expressions of osteogenic genes and proteins demonstrated CeO2 NPs could promote osteogenesis differentiation of hPDLSCs. Then we chose electrospinning to fabricate fibrous membranes containing CeO2 NPs. We showed that the composite membranes improved mechanical properties as well as realized release of CeO2 NPs. We then applied the composite membranes to in vivo study in rat cranial defect models. Micro-CT and histopathological evaluations revealed that nanofibrous membranes with CeO2 NPs further accelerated new bone formation. Those exciting results demonstrated that CeO2 NPs and porous membrane contributed to osteogenic ability, and CeO2 NPs contained electrospun membrane may be a promising candidate material for periodontal bone regeneration., Graphical abstract Schematic illustration of the in vitro and in vivo study of CeO2 NPs' effects on accelerating bone regeneration.Image 1, Highlights • CeO2 nanoparticles are induced in the therapy of periodontal regeneration as a bio-activator. • CeO2 nanoparticles have potential promotion on osteogenic differentiation of periodontal stem cells. • Fibrous membrane containing CeO2 nanoparticles was fabricated by electrospinning with biodegradable materials. • Incorporation CeO2 nanoparticles with PCL/gelatin enhance bone regeneration in rat critical bone defect.

Development of lignin-derived carbon adsorbents with ultrahigh phosphate adsorption activity and rapid adsorption kinetics is of great importance, yet limited success has been achieved. Herein, we develop a CeO2 functionalized N-doped lignin-derived biochar (Ce@NLC) via a cooperative modification strategy for effective and fast phosphate capture. The novel modification strategy not only contributes greatly to the loading of well-dispersed CeO2 nanoparticles with a smaller size, but also significantly increases the relative concentration of Ce(III) species on Ce@NLC. Consequently, an enhanced capture capacity for phosphate (196.85 mg g−1) as well as extremely rapid adsorption kinetics were achieved in a wide operating pH range (2–10). Interestingly, Ce@NLC exhibited a strong phosphate adsorption activity at even low-concentration phosphorus-containing water. The removal efficiency and final P concentration reached 99.87% and 2.59 μg P L−1 within 1 min at the phosphate concentration of 2 mg P L−1. Experiments and characterization indicated that Ce(III) species plays a predominant role for the phosphate capture, and ligand exchange, together with electrostatic attraction, are the main adsorption mechanism. This work develops not only an efficient carbon-based adsorbent for phosphate capture, but also promotes the high-value application of industrial lignin.

The physicochemical properties of ablated cerium dioxide nanoparticles have been studied in the photocatalytic degradation of methylene blue in the presence of a ZnO nanocatalyst. It was shown that in the photocatalytic process, CeO2 nanoparticles exhibit good antioxidant properties due to an increased content of structural defects in the surface atomic layers of ablated nanoparticles. It was found that the antioxidant activity of the particles increases with a growth of the pH of the aqueous solution.

In this paper, rare earth oxide CeO2 nanoparticle-doped polymer dispersed liquid crystal (PDLC) films were prepared by the polymerisation induced phase separation (PIPS) process. The effects of the...

Cobalt sulfide is favorable for supercapacitors, but its application is inhibited by the inherent slow charge transfer kinetics and poor stability in alkaline solution. Herein, zeolitic imidazole f...

Generally, several mechanisms influenced the secondary injury chutes following acute spinal cord injury (SCI). Though current SCI therapeutic approaches mostly target single elements in the injury chutes, they have been mostly ineffective in clinical trials. The aim of this study was to design and develop a novel cerium oxide/silk fibroin (CeO2/SF) hydrogel material loaded with minocycline (MCN) and transplantation of olfactory ensheathing cells (OEC) for SCI treatment. The prepared CeO2/SF hydrogel has an advantageous porous morphological structure and CeO2 NPs were greatly encapsulated on the surface, which was confirmed by microscopic observations. The results of in vitro analyses established favourable biocompatibility of 94.65% and 89.45%, sustained drug release rate of 89% and 58%, and significant reduction in pro-inflammatory factors for the treatments using cerium oxide loaded silk fibroin (CSF) and CeO2 NPs, respectively. Meanwhile, the administration of MCN@OEC greatly provides an efficient improvement in BBB score, decreased bladder weight, and histological improvement after SCI when compared to the control. Therefore, the combined MCN and OEC-loaded CSF hydrogel sample could be proved as a low cost, safe, and potential material for the treatment of SCI.

In this work, a simple facile preparation of Ce1-xAlxO2-δ (where x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5) nanoparticles by chemical synthesis route is reported. In the preparation, appropriate quantities of metal nitrate salts were dissolved in water alongwith required amount of sodium hydroxide as precipitant. The resultant precipitate mixture [Ce(OH)3 + Al(OH)3] was washed with water, filtered, dried and heat treated to get the phase pure Al doped CeO2 nanoparticles. The synthesized oxide materials were characterized by XRD, FTIR, particle size analysis, SEM and EDAX to understand their structural, functional and particle properties. The XRD patterns revealed the presence of cubic (FCC) crystalline structure in the samples. The presence of Al-O and Ce-O stretching mode of vibration was confirmed by FTIR analysis. The particle size of the materials was found in the range of 117.23 to 257.06 nm. Presence of nano and micron sized grains was noticed by SEM photographs. EDAX confirmed the presence of appropriate atomic weight percentage of elements in the samples. The results suggested that the prepared Al doped ceria nanoparticles can be useful in several applications.

The development of highly active electrocatalytic labels is important for constructing sensitive electrochemical immunosensors. Great progress has been made in developing non-noble-metal nanocatalysts toward the oxygen evolution reaction (OER) in the past decade, but non-noble-metal OER nanocatalysts have not been explored as electrocatalytic labels for immunosensing. Herein, we report NiCoO2@CeO2 nanoboxes (NBs) as novel electrocatalytic labels for ultrasensitive immunosensing based on the excellent OER activity of NiCoO2@CeO2 NBs in a neutral solution. The synthesis of NiCoO2@CeO2 NBs involves Ni2+ exchange and heat treatment of ZIF-67 nanocubes to produce NiCoO2 NBs, followed by the growth of CeO2 nanoparticles on the surface of NiCoO2 NBs. The NiCoO2@CeO2 NBs offer superior OER activity to NiCoO2 NBs because of the synergetic effect between NiCoO2 NBs and CeO2 nanoparticles. The formation of ester-like bridging between CeO2 and the carboxylic groups of antibody enables direct immobilization of the antibody on the NiCoO2@CeO2 surface. A sandwich-type electrochemical immunosensor using NiCoO2@CeO2 NBs as electrocatalytic labels features a broad linear range for interleukin-6 detection from 2.5 × 10-5 to 10 ng mL-1, with a low detection limit of 7 fg mL-1. Our work lays the foundation for developing electrochemical immunosensors and aptasensors based on non-noble-metal OER electrocatalysts.

Comparison of bio CeO2-Nps prepared using Trianthema Portulastrum leaf extract with chemical CeO2-Nps is of interest. The ultraviolet - visible, x-ray diffraction, HR - TEM, FT - IR, and photoluminescence studies were conducted with CeO2-Nps. UV–Maximum absorptionat 292 nm was completed using UV-visible spectrum. The HR–TEM images showed 38 nm bio CeO2-Nps with spherical morphology. This showed the polycrystalline character of CeO2-Nps similar to XRD data. The presence of metal oxide is confirmed by FT - IR analyses. The CeO2-Nps showed the potential photocatalytic activity for Acid black 1 color degradation after exposure to sunlight. Chem and bio CeO2-Nps have a degradation rate of 86.66 and 94.33%, respectively for acid black 1 dye. The synthesized CeO2-Nps are also evaluated for antibacterial and antioxidant activity. The bio CeO2-Nps has antibacterial activity for Pseudomonas aeruginosa (17 ± 0.56 mm) and Staphylococcus aureus (16 ± 0.24 mm) at low concentrations of 100 μl. The CeO2-Nps bio showed high inhibition of radical DPPH IC50 μg/ml, at 95.17 ± 21. Thus, we show that CeO2-Nps have environmentally friendly properties that are useful for dye degradation with antimicrobial and antioxidant activities.

Ultrasmall ceria (CeO2) and metal-doped CeO2 nanoparticles in the sub-3 nm size regime were synthesized via a facile, single-step, liquid-phase thermal decomposition reaction in a monosurfactant me...

Ag@CeO2 with a rice-ball configuration as a heterogeneous and highly efficient catalyst was described for activation of H2O2 in the selective oxidation of aromatic and aliphatic sulfides to their corresponding sulfones. Ag nanoparticles in the CeO2–Ag interface increase the oxygen vacancy defects on the surface of CeO2 and oxygen vacancy defects promote the reduction of Ce4+ to Ce3+ to keep the electroneutrality. Generated Ce3+ species act as the active sites in the interface of CeO2–Ag to promote the oxidation of sulfides to sulfones. Compatibility with various aromatic and aliphatic sulfides, excellent selectivity, high yield of product, simple experimental procedure, and mild reaction conditions are some of the precious advantages of Ag@CeO2/H2O2 catalyst system.

In spite of good sun protection characteristics, nanocrystalline TiO2 and ZnO widely used as inorganic UV filters can display a negative effect on skin. Nanocrystalline cerium dioxide was proposed as a promising component of sun protection cosmetics, however, no quantitative comparison of sun protection characteristics of CeO2 with other metal oxides was carried out until now. In this work, we experimentally determined for the first time the values of sun protection factor and UVA protection factor for CeO2 nanoparticles in accordance with the State Standard ISO 24443-2016 and compared them with characteristics of TiO2 and ZnO. Effect of size factor on CeO2 sun protection characteristics has been found.

Intensive use of engineered nanoparticles (NPs) results in their release into aquatic systems and consequently into drinking water resources. Therefore, it is important to evaluate how NPs can be effectively removed through water treatment processes, such as coagulation, to control environmental and health risks associated with NP exposure. This work investigates the effect of two conventional coagulants, polyaluminum chloride (PACl) and iron chloride (FeCl3 ), on NPs. Three bottled mineral and Lake Geneva waters, currently used as drinking water resources, were considered to get an insight into coagulation efficiency. TiO2 , CeO2 NPs, and polystyrene (PS) nanoplastics were selected, owing to their large number of applications and contrasting surface charge and aggregation behavior at environmental pH. Our findings indicate that PACl is more efficient compared with FeCl3 since lower dosages are required to coagulate all nanoparticles. On the other hand, nanoplastic coagulation is found less efficient compared with TiO2 and CeO2 NPs. This is an important outcome indicating that nanoplastic stability and dispersion state will be more pronounced and therefore more challenging to eliminate. Results highlight the key role of NP and PS nanoplastic surface charge, as well as water properties, coagulant type, and dosage on nanoparticle elimination from aquatic systems. PRACTITIONER POINTS: pH, water hardness, and NOM are playing roles in final coagulant dosage concentration. PACl is more efficient than FeCl3 in most conditions. Positively charged nanoplastics are more difficult to eliminate by coagulation. NP surface properties in bottled mineral and surface waters are controlled by pH, divalent cations, and NOM. NP surface charge and coagulation efficiency depend on water properties.

CeO2 nanoparticles were decorated on graphene sponge and used for adsorption and photodegradation of methylene blue. They were characterized by X-ray diffraction (XRD), scanning electron microscopy...

CeO2–x quantum dots with massive oxygen vacancies are obtained by a one-step single molecular synthesis strategy. The yield of dimethyl carbonate from CO2 and methanol is more than 5 times that for commercial CeO2 nanoparticles.

Development of novel electrode materials for sensing water pollutant like nitrite, nitrate, paramedical pollutants and fertilizers is a more promising research area in electrochemical sensor field. Various pure as well as doped metal oxides were used as electrodes for sensing the water pollutants but, deficits in stability, reproducibility and real time analysis. In the present work, a promising Sn-doped CeO2 based sensor was fabricated for sensing nitrite in water. A selective concentration of Sn (5%) doped CeO2 nanoparticles were synthesized by facile chemical precipitation method. The structural, optical and morphological information were studied using various techniques. The morphological of the sample was revealed an agglomerated with spherical nanoparticles with size of 8.5 nm. The synergistic effect of Sn-CeO2/GCE improves the electrochemical behavior of nitrite on the modified surface. Sn-doped CeO2 nanoparticles has a better surface property and provides a more fine-grained media to facilitate electron transfer during the reaction between analyte and electrode. The Sn-CeO2/GCE electrode possesses excellent electrocatalytic oxidation of nitrite (NO2–) which was investigated by cyclic voltammetry (CV) and amperometry techniques. The remarkable sensitivities of nitrite were found that 245.4 µA cm−2 mM−1 and 89.53 µA cm−2 mM−1 with R2 = 0.999 and RSD of ∼ 6%. Similarly, the limit of detection (LOD) towards nitrite ion sensing was found to be 16 nM. The real time application of Sn-CeO2/GCE sensor was demonstrated by the detection of nitrite present in environmental water samples with excellent recoveries. Hence, Sn-doped CeO2 modified electrode also demonstrates good reproducibility, long time stability, and excellent selectivity properties. Thus, a developed electrochemical sensor possesses a novel promise for the construction of simple and sensitive nitrite analytical stage. © 2021 Elsevier B.V. The authors thank Chancellor, President and Vice Chancellor, Sathyabama Institute of Science and Technology, Chennai for the support and encouragement. The author R. Jothi Ramalingam thank for the financial support by the Researchers Supporting Project Number (RSP-2021/354), King Saud University, Riyadh, Saudi Arabia.

Flexible materials, such as fabric, paper and plastic, with nanoscale particles that possess antimicrobial properties have a significant potential for the use in the healthcare sector and many other areas. The development of new antimicrobial coating formulations is an urgent topic, as such materials could reduce the risk of infection in hospitals and everyday life. To select the optimal composition, a comprehensive analysis that takes into account all the advantages and disadvantages in each specific case must be performed. In this study, we obtained an antimicrobial textile with a 100% suppression of E. coli on its surface. These CeO2 nanocoatings exhibit low toxicity, are easy to manufacture and have a high level of antimicrobial properties even at very low CeO2 concentrations. High-power ultrasonic treatment was used to coat the surface of cotton fabric with CeO2 nanoparticles.

Nanotechnology presents a huge potential for plant nutrition. In this sense, foliar application of fertilizers has the advantages of delivering nutrients, reducing the environmental impact in relation to soil application. This study has investigated the effects of foliar application of CuO and CeO2 nanoparticles on soybean plants. Copper was chosen due to its importance as a nutrient for higher plants and all the processes the element participates. Cerium is the most abundant rare earth element in the Earth\'s crust and its abundance is not that different compared with Zn and Cu, which are much more involved in environmental investigations than Ce. During the study, it was attempted to develop an X-ray spectrometric method to trace the uptake and redistribution of nanoparticles in living plants. Even tough this was not possible, such method allowed to access the nutrional status of soybean under vivo conditions. The deposition of copper sources on leaves, such as nano and micro CuO and copper sulphate, caused damages, inducing to absence or scarce presence of platelets crystals. Shoot dry mass of plants was positively affected by the treatments, especially by the 40 nm nCuO. Copper speciation showed that the element undergoes redox reactions from Cu1+ to Cu2+ after 14 days of application. The nanoparticles were able to supply Cu and Ce to soybean since these elements were found in other plant tissues that were not directly exposed to the nanoparticles. However, it is not clear whether the particles are dissolved outside the leaves or taken up entirely. The use of cerium nanoparticles did not interfere in agronomic parameters such as biomass production and number of pods A nanotecnologia possui potencial aplicação à nutrição mineral de plantas. A aplicação foliar de fertilizantes tem como uma de suas principais vantagens a aplicação específica do nutriente, reduzindo assim o impacto ambiental em relação à aplicação no solo. Este estudo investigou os efeitos da aplicação foliar de nanopartículas de CuO e CeO2 em plantas de soja. O cobre foi escolhido devido à sua importância como nutriente e por todos os processos metabólicos que o elemento participa. O cério é o elemento terra rara mais abundante na crosta terrestre, e é sujeito de várias investigações ambientais, mas sua essencialidade no metabolismo ainda não foi demonstrada. Durante este estudo, tentou-se desenvolver um método de espectrometria de raios X para rastrear a absorção e redistribuição de nanopartículas em plantas vivas. Mesmo não sendo possível, tal método permitiu acessar o estado nutricional de plantas de soja sob condições in vivo. A deposição de fontes de cobre, como nano e micro CuO e sulfato de cobre, nas folhas causou danos, induzindo a ausência ou presença escassa de cristais. Massa seca da parte aérea foi afetada positivamente pelos tratamentos, especialmente pela nanoparticícula de óxido de cobre de 40 nm. A especiação de cobre mostrou que o ele é transformado de Cu1+ em Cu2+ após 14 dias de exposição. As nanopartículas foram capazes de fornecer Cu e Ce à soja, uma vez que esses elementos foram encontrados em outros tecidos vegetais que não foram diretamente expostos às nanopartículas. No entanto, não está claro se as partículas são dissolvidas fora das folhas ou absorvidas inteiramente. O uso de nanopartículas de cério não interferiu em parâmetros agronômicos como produção de biomassa e número de vagens

[Abstract] Metal oxide nanoparticles (NPs) have a wide variety of applications in many consumer products and biomedical practices. As a result, human exposure to these nanomaterials is highly frequent, becoming an issue of concern to public health. Recently, human salivary leucocytes have been proposed as an adequate non-invasive alternative to peripheral blood leucocytes to evaluate genotoxicity in vitro. The present study focused on proving the suitability of salivary leucocytes as a biomatrix in the comet assay for in vitro nanogenotoxicity studies, by testing some of the metal oxide NPs most frequently present in consumer products, namely, titanium dioxide (TiO₂), zinc oxide (ZnO), and cerium dioxide (CeO₂) NPs. Primary and oxidative DNA damage were evaluated by alkaline and hOGG1-modified comet assay, respectively. Any possible interference of the NPs with the methodological procedure or the hOGG1 activity was addressed before performing genotoxicity evaluation. Results obtained showed an increase of both primary and oxidative damage after NPs treatments. These data support the use of salivary leucocytes as a proper and sensitive biological sample for in vitro nanogenotoxicity studies, and contribute to increase the knowledge on the impact of metal oxide NPs on human health, reinforcing the need for a specific regulation of the nanomaterials use. This research was funded by Xunta de Galicia [ED431B 2019/02]; Ministerio de Ciencia e Innovación (PID2020-114908GA-I00); Ministerio de Educación, Cultura y Deporte [BEAGAL18/00142, to V.V.]; CA17140 NANO2CLINIC COST Action; NanoBioBarriers (PTDC/MED-TOX/31162/2017) funded by Operational Program for Competitiveness and Internationalisation through European Regional Development Funds (FEDER/FNR) and through national funds by the Portuguese Foundation for Science and Technology (FCT). NanoLegaTox (POCI-01-0145-FEDER-029651) funded by Operational Program for Competitiveness and Internationalisation (COMPETE 2020) through FEDER, and through national funds by the Portuguese Foundation for Science and Technology (FCT). A.T. Reis funded by FCT Grant SFRH/BPD/122112/2016 Xunta de Galicia; ED431B 2019/02 European Cooperation in Science and Technology; CA17140 Portugal. Fundação para a Ciência e a Tecnologia; PTDC/MED-TOX/31162/2017 Portugal. Fundação para a Ciência e a Tecnologia; POCI-01-0145-FEDER-029651 Portugal. Fundação para a Ciência e a Tecnologia; SFRH/BPD/122112/2016

Catalysts that can work without the need of light and additional oxidants such as H2O2 to degrade organic pollutants have been long sought. In this work, we report that at acidic condition, CeO2 na...

Herein, we report the high performance of Bi2O3 interacted with ultrafine CeO2 nanoparticles (NPs) for soot oxidation. With the increased Bi content, Bi2O3 can be tuned from the amorphous phase to ...

Background:We synthesized cerium oxide (CeO2) nanoparticles (NPs) via green synthesis method mediated with Rajma seeds powder as a fuel and cerium nitrate as an oxidizer.Objective:The obtained cerium oxide nanoparticles are used to study the various environ mental appilications.Methods:The achieved CeO2 nanoparticles are tested using PXRD (Powder X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), electron microscopic studies including SEM, Raman spectroscopy, UV-Visible spectroscopy. Formation of agglomerated cubic phased CeO2 nanoparticles were confirmed from both PXRD and SEM.Results:The average crystallite size of CeO2 nanoparticles was found to be 38 nm calculated from highly intense peak using Debye-Scherer’s formula. The characteristic Ce-O stretching was confirmed by FTIR and Raman studies. CeO2 nanoparticles are promising material for the organic dye degradation. Photocatalytic activities evaluation under various parameters like sunlight, UV light and variation of PH, catalytic dosage etc. CeO2 nanoparticles exhibit highly enhanced photo degradation of Methylene Blue dye. Kinetics and isotherm models of Photocatalysis were studied.Conclusion:We have prepared CeO2 nanoparticles by low-temperature combustion technique using Rajma germinated and Rajma non- germinated seeds as fuel. The XRD pattern confirms the formation of cubicphase CeO2 nanoparticles. The existence of Ce-O vibration is confirmed by FTIR and Raman spectra of the CeO2 nanoparticles. The UV-Visible spectra of CeO2 nanoparticles reveal the absorbance band range at 350-390 nm. SEM images of CeO2 nanoparticles indicates the agglomerated with irregular morphology. CeO2 nanoparticles are favorable material for the organic Methylene blue dye degradation. The different amount of the Rajma influences improved Photodegradation of cerium oxide nanoparticles was characteristics of slight crystal dimension, new superficial deficiencies, more band hole and ability to make smaller the electron-hole pair rearrangement. Adsorption kinetics results show that adsorption of MB over cerium oxide follows pseudo-first-order and second-order kinetics. Using the Langmuir isotherm, Freundlich isotherm, maximum adsorption capacity is calculated. Thus it can be used as attractively recoverable nano adsorbent for the removal of MB dye by adsorption technique from effluent water.

Made available in DSpace on 2019-10-06T16:31:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-09-30 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul With the continued increase of technological uses of cerium oxide nanoparticles (CeO2 NPs or nanoceria)and their unregulated disposal, the accumulation of nanoceria in the environment is inevitable. Concomitantly, atmospheric carbon dioxide (CO2)levels continue to rise, increasing the concentrations of bicarbonate ions in aquatic ecosystems. This study investigates the influence of CeO2 NPs (from 0 to 100 μgL−1)in the presence and absence of an elevated bicarbonate (HCO3 −)ion concentration (1 mM), on vibrational biochemical parameters and photosystem II (PSII)activity in leaf discs of Salvinia auriculata. Fourier transform-infrared photoacoustic spectroscopy (FTIR-PAS)was capable of diagnostic use to understand biochemical and metabolic changes in leaves submitted to the CeO2 NPs and also detected interactive responses between CeO2 NPs and HCO3 − exposure at the tissue level. The results showed that the higher CeO2 NPs levels in the presence of HCO3 − increased the non-photochemical quenching (NPQ)and coefficient of photochemical quenching in dark (qPd)compared to the absence of HCO3. Moreover, the presence of HCO3 − significantly decreased the NPQ at all levels of CeO2 NPs demonstrating that HCO3 − exposure may change the non-radiative process involved in the operation of the photosynthetic apparatus. Overall, the results of this study are useful for providing baseline information on the interactive effects of CeO2 NPs and elevated HCO3 − ion concentration on photosynthetic systems. Grupo de Estudos em Recursos Vegetais Universidade Estadual de Mato Grosso do Sul, CP 350 Programa de Pós-Graduação em Recursos Naturais Centro de Estudos em Recursos Naturais Universidade Estadual de Mato Grosso do Sul, CP 350 Laboratório de Nanoquímica Ambiental Departamento de Física e Química Faculdade de Engenharia de Ilha Solteira Universidade Estadual Paulista (UNESP), Avenida Brasil, 56, Centro, Ilha Solteira Grupo de Óptica Aplicada Universidade Federal da Grande Dourados, CP 533 Grupo de Espectroscopia Óptica e Fototérmica Universidade Estadual de Mato Grosso do Sul, CP 350 Grupo de Óptica e Fotônica Instituto de Física Universidade Federal de Mato Grosso do Sul, CP 549 Laboratório de Nanoquímica Ambiental Departamento de Física e Química Faculdade de Engenharia de Ilha Solteira Universidade Estadual Paulista (UNESP), Avenida Brasil, 56, Centro, Ilha Solteira CNPq: 465360/2014-9

The main goal of the study was to evaluate the avoidance behaviour of isopods (Porcellio scaber) to food or soil contaminated with different nanoparticles (NPs): Ag-NPs, sulfidized Ag-NPs (Ag2S-NPs) or CeO2-NPs. These NPs are characterized by different physiochemical properties, and antimicrobial and toxic potentials. Isopods were exposed in three scenarios: (i) 14 d feeding test where animals were fed solely on contaminated leaves; (ii) 14 d food selection test where leaves spiked with NPs were offered simultaneously with uncontaminated leaves; and (iii) 48 h soil avoidance test where animals could choose between uncontaminated and soil spiked with NPs. The isopods decreased feeding on Ag-NP contaminated food and clearly avoided contact with Ag-NP contaminated soil. Substantial accumulation of Ag in the body of isopods was found both in feeding and food selection test. This means that food selection might mitigate but could not prevent Ag accumulation in woodlice. In contrast, no such behavioural response of isopods was found for CeO2-NP. These data suggest that the presence of metal ions in the case of Ag-NPs may be the main reason for differential behaviour. Interestingly, moderate avoidance behaviour was observed also towards Ag2S-NPs although no Ag+ was detected in stock suspensions. This avoidance was not statistically significant and needs to be further explored. Behavioural test with isopods showed again their value in estimation of potential adverse effects of pollutants comparable to collembolans and earthworms.

Electrospinning of fibrous bandage material based on poly(vinyl alcohol) containing CeO2 nanoparticles was investigated. Medical and biological effects of Ce compounds on post-burn scartissue deformation were assessed experimentally. The release kinetics of nanoparticles from the fibrous material were studied. The results demonstrated that use of fibrous materials containing CeO2 nanoparticles (1%) as wound dressings was promising.

Nanoceria green synthesis using Pisonia alba leaf extract was reported in this study. UV–Vis spectroscopy, TEM, EDX, XRD and FTIR were employed to characterize the synthesized nanoceria (CeO2 nanoparticles). The nanoceria synthesis and size were confirmed by UV–Vis and TEM analysis. The cerium signals observed in the EDX spectrum revealed that the synthesized nanoceria was pure in nature. The cubic fluorite crystal structure of the nanoceria was confirmed from XRD analysis. The chemical bonds pertaining to the bioreducing phytochemicals in P. alba leaf extract were identified by FTIR analysis. Nanoceria showed good antioxidant activity which was assessed by DPPH and FRAP assay. P. alba leaf extract derived nanoceria was highly inhibited the growth of Aspergillus flavus and Fusarium solani fungal strains. The antioxidant and antifungal properties of P. alba leaf extract derived nanoceria can make it as a suitable candidate for biological applications.

This study aims to assess the role of iron plaque (IP) on cerium (Ce) uptake and translocation by rice after CeO2 nanoparticles (NPs) exposure over a 4 days period. A hydroponic experiment was performed under two IP levels (low and high) combined with two CeO2 NPs size (14 nm and 25 nm). It was found that CeO2 NPs as the main form was absorbed by rice due to limited NPs dissolution in hydroponic solution. IP significantly reduced surface-Ce, root-Ce and shoot-Ce accumulation, irrespective of CeO2 NPs sizes. The reduced uptake of Ce was more obvious in NP25 than NP14. Ce accumulations decreased with increasing IP amounts. In IP treatments, the interactive attraction between NPs and root surface was weakened through the enhancement of hydrodynamic diameters and the reduction of ζ-potential of CeO2 NPs in solution, as well as the reduction of |ζ| values of rice root, which reduced the Ce bioaccumulation in rice. PCA indicated the negative correlation between surface-Ce (IP-C-Ce and IP-A-Ce) and NPs size, and between shoot-Ce/root-Ce and IP-Fe/tissue-Fe. IP also decreased Ce translocation from root to shoot. A full life study indicated the reduction effect of IP on surface-Ce, root-Ce, shoot-Ce and grain-Ce accumulations. These findings are significant as they imply that the IP formation is a promising approach for preventing Ce accumulation in rice, which would regulate Ce uptake by rice in the following growth stages and decrease the health risk of CeO2 NPs exposure in agricultural environment.

Monodispersed cerium oxide nanoparticles (CeO2 NPs) with positive and negative surface potential were synthesized by co-precipitation method using hexamethylenetetramine (HMT) and poly(vinylpyrrolidone) (PVP), respectively, as precipitating agents. Synthesized NPs were characterized with scanning electron microscopy (SEM), UV–Visible (UV-Vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and powder X-ray diffraction (XRD). Positively charged NPs of about 30 ± 10 nm in size formed within 5 h, aggregated in number, and resulted in larger-sized NPs as a function of time. The CeO2 NPs were administered to Drosophila as a part of their diet to study the effects on the growth and development of Drosophila. While the positively charged NPs did not affect the growth of the third instar larvae, the negatively charged NPs delayed the growth of larvae by about 7 days. It required 7 more days to reach the stage of adult fly. TEM imaging of the larvae gut showed that positively charged NPs were found to be smaller, whereas the size of negatively charged NPs remained unchanged. This biodegradability could be the reason for the delayed larvae growth in the case of negatively charged particles. The distance covered by such second instar larvae fed with diet containing negatively charged CeO2 NPs was significantly lower, and their size was significantly smaller when compared to the crawling activity and size of the third instar larvae of the control group. Such positively charged NPs have high potential for use as drug delivery carriers for the treatment of disease, and negatively charged NPs may play a rather detrimental role.

We herein communicate the DNase I like activity of nanoceria (CeO2 nanoparticles). Both CeO2 and DNase I cleave polyadenine (poly-A) DNA down to ∼5-mer fragments as the major products, although further cleavage to even shorter fragments was observed with CeO2. Mass spectrometry indicates a hydrolytic cleavage mechanism instead of oxidative cleavage.

Linen fabric lacks functional properties which can be imparted using CeO2 nanoparticles; however, the efficiency and durability against the repeated washing is always a big limitation. Wash-durable functionalization thus can be achieved by surface modification using chitosan-based recipes which can also impart additional functional properties to linen. In the present work, the modification of linen fabric was achieved using a chitosan-based recipe followed by in-situ synthesis of CeO2 nanoparticles on chitosan-treated fabrics. The modified fabric was characterized using FTIR, TGA, SEM and EDX techniques and further evaluated towards functional properties. The modified linen displayed highly effective antibacterial activity against S. aureus and E. coli bacteria. The additional functional properties like wrinkle resistance, UV protection and flame retardancy were also achieved using such dual modification. Most of the functional properties were retained in a satisfactory level after five subsequent washes. The modified linen thus can be claimed as a suitable candidate for functional apparels and technical textiles.

CeO2 nanoparticles (NPs) have shown promising results as therapeutic agents in biology and medical sciences. In this study, CeO2-NPshave been synthesized through green synthetic approach by applying natural matrices(fruit of Annona muricata) as stabilizing agents in order to prepare biocompatible CeO2-NPs, thereby solving the challenges regarding safety, and providing the appropriate properties for their effective use in biomedical field.The synthesized CeO2 nanoparticles are characterized by XRD, FTIR, UV-DRS, FESEM, EDAX, PL and antimicrobial analysis. UV-DRS analysis shows that formation of CeO2 nanoparticles with maximum absorption at 318 nm.The antibacterial activities of synthesized CeO2 NPs were carried out against the human pathogenic microorganism by agar-well diffusion method.

Cerium dioxide nanoparticles were prepared by the sol-gel method using cellulose as a template and used in the synthesis of 2-oxazolidinone from urea and 2-aminoethanol under solvent-free conditions. All the reaction parameters were optimized to obtain the best selectivity and conversion. The selectivity of 100 % to 2-oxazolidinone with a pretty complete conversion of about 98.4 % was achieved. The prepared catalyst was characterized by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and volumetric isothermal nitrogen gas adsorption-desorption method (BET).

CeO2 nanoparticles were incorporated in waterborne binders containing high biobased content (up to 70%) in order to analyze the anticorrosion performance for direct to metal coatings. Biobased binders were synthesized by batch miniemulsion polymerization of 2-octyl acrylate and isobornyl methacrylate monomers using a phosphate polymerizable surfactant (Sipomer PAM200) that lead to the formation of phosphate functionalized latexes. Upon the direct application of such binders on steel, the functionalized polymer particles were able to interact with steel, creating a thin phosphatization layer between the metal and the polymer and avoiding flash rust. The in situ incorporation of the CeO2 nanoparticles during the polymerization process led to their homogeneous distribution in the final polymer film, which produced outstanding anticorrosion performance according to the Electrochemical Impedance Spectroscopy measurements. In fact, steel substrates coated with the hybrid polymer film (30–40 µm thick) showed high barrier corrosion resistance after 41 days (~1000 h) of immersion in NaCl water solution and active inhibition capabilities thanks to the presence of the CeO2 nanoparticles. This work opens the door to the fabrication of sustainable hybrid anticorrosion waterborne coatings. This research was funded by the Spanish Government, grant numbers MINECO CTQ-2017-87841-R and CER-20191003, and by the Basque Government “Grupos Consolidados del Sistema Universitario Vasco”, grant number IT999-16.