Nanocrystalline Cerium Dioxide Research Articles

Mitochondrial dysfunction of the inner membrane of hepatocytes in the development of glutamate-induced steatohepatosis and its correction

Elucidation of the mechanisms of the development of liver steatosis, which are at the heart of the pathogenesis of nonalcoholic fatty liver disease (NAFLD), will allow the introduction of new effective treatment methods into medical practice, as well as the development of new measures for the correction of this disease and accompanying pathologies. The purpose of the research is to establish the enzymatic activity of the complexes of the electron transport chain of the mitochondrial membrane of rat hepatocytes and to evaluate the corrective effect of the multiprobiotic “Symbiter acidophilic” concentrated or nanocrystalline cerium dioxide on the formation of steatohepatosis induced by neonatal sodium glutamate administration. The experiments were carried out on 50 white non-linear male rats; the direction included the study of the mechanisms of the development of steatohepatosis in 4-month-old rats, which were administered monosodium glutamate in the neonatal period, and the study of the functional state of the liver in rats after the neonatal administration of monosodium glutamate against the background of periodic administration of a multiprobiotic or nanocrystalline dioxide cerium. It was established that neonatal administration of monosodium glutamate causes metabolic changes in 4-month-old rats, manifested in the disproportionate accumulation of fat with the development of visceral obesity without hyperphagia, dyslipidemia, and steatohepatosis. In 4-month-old rats, after neonatal administration of sodium glutamate, the development of steatohepatosis was accompanied by mitochondrial dysfunction, which was manifested by changes in the lipid composition of the inner membrane of hepatocyte mitochondria with an increase in oxidized products and a change in the enzymatic activity of all complexes of the respiratory chain. In rats injected with monosodium glutamate in the neonatal period, periodic use of the multiprobiotic “Symbiter acidophilic” concentrated or nanocrystalline cerium dioxide significantly restored the functional state of the liver, reduced the manifestations of oxidative stress and prevented the development of steatohepatosis, which indicates the antioxidant effect of these drugs and the possibility of their use for prevention of steatohepatosis.

Нанокристаллический диоксид церия как основа для создания функциональных материалов биомедицинского назначения

The paper summarises the recent advances in the functional inorganic biomaterials based on nanocrystalline cerium dioxide which possess pronounced antioxidant activity, UV-protective action, protect cells and living organisms from the negative effects of ionizing radiation.

Nanocrystalline Cerium Dioxide Affects Erythrocyte Membrane State Under Blood Hypothermic Storage

Here, we have studied the impact of nanocrystalline cerium dioxide (NCD) particles on erythrocyte membrane state in a model of hypothermic storage of blood samples by examining the content of lipid peroxidation (LPO) primary products and hematological indices (free and total hemoglobin, hematocrit and hemolysis levels). After hypothermic storage of blood samples within 5 weeks, no significant difference in hematological indices between the control and experimental groups was revealed. In 2 weeks of hypothermic storage, the cells from experimental group in NCD presence showed an increased content of mainly those primary LPO products, which precursors were polyunsaturated fatty acids with two double bonds (conjugated dienes and oxidienes), thereby indicating the free radical processes activation. Four weeks’ storage demonstrated significantly decreased content of all primary LPO products in the experimental group cells in contrast to the control group. To the final step of the study (5 weeks of storage), the content of all primary LPO products in experimental and control groups was similar, that was an evidence of the ability of NCD particles to affect the erythrocyte membrane as well change the LPO intensity depending on storage period.

Nucleotide Interaction with Nanocrystalline Ceria Surface

The adsorption of nucleotides on the surface of nanocrystalline cerium dioxide (pHpzc = 6.3) in NaCl solutions was investigated using multi-batch adsorption experiments over a wide range of pH. The obtained results were interpreted as a formation of outer and inner sphere surface complexes with the participation of phosphate moieties. The Basic Stern surface complexation model was applied to obtain quantitative equilibrium reaction constants.

Nanoparticles of Cerium Dioxide and Pristine (Unmodified) Fullerene C60 Protect Living Cells against Adverse Environmental Exposure: Does it Work?

We believe that unmodified hydrated C60 fullerene (C60FWS) and nanocrystalline cerium dioxide (NCD) are promising for biological research. It is knowns that these nanoparticles protect living cells from damaging environmental factors such as radioactive and ultraviolet radiation, temperature, hypoxia, toxic substances, etc. However, little attention has been paid in scientific reports to the use and study of these nanoparticles as possible adaptogens. In our studies, we tried to protect the culture of cyanobacteria Spirulina platensis with C60 and NCD from adverse conditions. The choice of Spirulina platensis is due to its sensitivity to adverse environmental factors. The results obtained show that the absence of toxic effects of C60 and NCD of selected concentrations on the Spirulina platensis culture has been found. Nanoparticles C60 and NCD maintained the culture of Spirulina platensis for at least 4 weeks in the absence of nutrients, light, low pH storage conditions and low temperature. Cyanobacteria stored for 1–4 weeks in distilled water with nanoparticles showed increased proliferative activity compared to samples stored at the same time in the standard Zarrouk’s nutrient medium.
 Keywords: fullerene C60, nanocrystalline cerium dioxide, Spirulina platensis, adaptogens.

Facile Synthesis of Stable Cerium Dioxide Sols in Nonpolar Solvents.

A method is proposed for the preparation of stable sols of nanocrystalline cerium dioxide in nonpolar solvents, based on surface modification of CeO2 nanoparticles obtained by thermal hydrolysis of concentrated aqueous solutions of ammonium cerium(IV) nitrate with residues of 2-ethylhexanoic and octanoic acids. The synthesis was carried out at temperatures below 100 °C and did not require the use of expensive and toxic reagents. An assessment of the radical-scavenging properties of the obtained sols using the superoxide anion-radical neutralization model revealed that they demonstrate notable antioxidant activity. The results obtained indicate the potential of the nanoscale cerium dioxide sols in nonpolar solvents to be used for creating nanobiomaterials possessing antioxidant properties.

Influence of nanocrystalline cerium dioxide on antigens of non-specific protection of quails

Intensive poultry farming technologies are closely linked to a variety of environmental, technological, feed and biological stressors, which tend to negatively affect their productivity and immune defenses. In the pathogenesis of such detrimental effects, the leading role belongs to the overproduction of oxygen free radicals - oxidative stress. The latter activates a number of transcription factors, including Nrf-2 and Nf-kB, which modulate the antioxidant defense network and participate in the organization of infection control. NDC is able to reduce the activation of Nf-kB and thus maintain antioxidant balance, but the response of the immune system to this factor is insufficiently studied. The aim of our work is to investigate the effect of NDC on the antigen of non-specific immunity of quails by adding it to drinking water. The object of study were the quail of the Pharaoh breed, experimental and control groups formed at the age of one day on the principle of analogues. The birds were kept in cages with free access to food and water. Quails of the experimental group in drinking water was added to the feed additive Nanocerium at a dose of 8.6 mg per liter of drinking water. This additive is an aqueous dispersion of NDC with an average nanoparticle size of 2-7 nm. The average weight of quails at the end of the experiment (56 days) in the experimental group was 20.2 g greater than in the control. Morphometric studies of the thymus, bursa and spleen showed no effect of NDC on the central and peripheral immune systems. Morphological parameters of the blood were within the physiological norm, but in the experimental group the number of erythrocytes and hemoglobin content were higher. The leukocyte count showed an increase in the leukocyte count (according to Garkavi LH) in the experimental group. Humoral performance was identical in both groups. Studies of cellular defense indicate no effect on the phagocytic function of peripheralblood cells. Functional and metabolic activity under the influence of NDC in the spontaneous test probably did not differ and increased in the stimulated. Therefore, quails that received nanocerium feed additive with water had a higher immunoresistance. Key words: birds, nanocerium, morphometry, thymus, natural immunity, morphological parameters of blood, hematopoiesis, humoral immunity, cellular immunity, hematological parameters. Accepted abbreviations: NDC – nanocrystalline cerium dioxide, ROS – reactive oxygen species, Nf-kB – nuclear factor - kV, Nrf-2 – nuclear factor - erythroid 2 and related factor 2.

Phosphate–nucleotide–nucleic acid: Adsorption onto nanocrystalline ceria surface

The adsorption of deoxyribonucleic acid (DNA) and its constituents – phosphate and nucleotides on the surface of nanocrystalline cerium dioxide (pHpzc = 6.3) in NaCl solutions was investigated using multi batch adsorption experiments over a wide range pH. The adsorption data of inorganic phosphate, and nucleotides were interpreted as a formation of outer and inner sphere surface complexes in term of the Basic Stern surface complexation model. The comparison of adsorptions of DNA, phosphate and nucleotides has revealed that double-stranded DNA is mainly adsorbed with the participation of phosphate backbone of its molecule. The approach of DNA to the oxide surface due to the electrostatic attraction promotes other types of interaction, e.g. dispersion interaction and hydrogen bonding.

High Pressure Brillouin Spectroscopy and X-ray Diffraction of Cerium Dioxide

Simultaneous high-pressure Brillouin spectroscopy and powder X-ray diffraction of cerium dioxide powders are presented at room temperature to a pressure of 45 GPa. Micro- and nanocrystalline powders are studied and the density, acoustic velocities and elastic moduli determined. In contrast to recent reports of anomalous compressibility and strength in nanocrystalline cerium dioxide, the acoustic velocities are found to be insensitive to grain size and enhanced strength is not observed in nanocrystalline CeO. Discrepancies in the bulk moduli derived from Brillouin and powder X-ray diffraction studies suggest that the properties of CeO are sensitive to the hydrostaticity of its environment. Our Brillouin data give the shear modulus, = 63 (3) GPa, and adiabatic bulk modulus, = 142 (9) GPa, which is considerably lower than the isothermal bulk modulus, 230 GPa, determined by high-pressure X-ray diffraction experiments.

Meat productivity of quails by feeding nanocrystalline cerium dioxide

The use of nanomaterials in poultry farming has become increasingly popular as feed additives capable of increasing the productivity of the herd. Nanocrystalline cerium dioxide belongs to nanomaterials with a broad spectrum of activity. Owing to their oxygen non-stoichiometry and low toxicity, cerium dioxide nanoparticles are a very promising object for agriculture. The paper presents the results of studying the meat productivity of quails of the Pharaoh breed when drinking nanocrystalline cerium dioxide in the composition of the feed additive “Nanocerium”. The study was carried out on quails during the rearing period from 14 to 49 days. For the experiment, two groups (control and experimental) of 24 heads each were formed from one day old poultry. The quails were kept in a vivarium, in cage batteries, subject to the accepted microclimate conditions. Poultry of both groups received compound feed, developed taking into account age and physiological characteristics. With drinking water, the of the experimental group additionally received nanocrystalline cerium dioxide as part of the feed additive “Nanocerium” at a dose of 8,6 mg per liter of water for 35 days. The quail population was counted and weighed weekly, starting from the day-old age. The following indicators were determined: safety, dynamics of live weight, average daily gain in live weight. According to the results of the control slaughter and anatomical cutting, the weight of the carcass and the weight of the edible part were determined. Slaughter qualities and morphological composition of quail carcasses were determined by anatomical cutting with the measurement of the following parameters: pre-slaughter weight, half-battered carcass weight, carcass patrana, slaughter yield, weight of edible parts. Drinking the feed additive “Nanocerium” by young quails increased their safety by 4.17%, live weight and absolute average daily gain by 20.3 g and 0.48 g (P <0.05), respectively. The addition of NDC quails to drinking water contributed to an increase in their pre-slaughter weight by 19.3 g, half-gutted carcass by 18.0 g, and gutted by 17.5 g in comparison with the control group. The quail carcasses of the experimental group had a higher yield of edible parts in comparison with the poultry that consumed pure water. Key words: quail, nanocrystalline cerium dioxide, safety, body mass, gain, slaughter rates, output of edible part.

Veterinary and sanitary characteristics of quail meat by feeding nanocrystalline cerium dioxide

The unresolved problem of quail is feed stress and high sensitivity of poultry of this species to feed quality. To eliminate such consequences it is possible with the use of various biologically active feed additives. However, their introduction into the diet automatically raises questions about the quality and safety of the products for the consumer. The purpose of the research is to conduct a veterinary and sanitary assessment of the quality of quail meat for feeding NDC. The purpose of the research is to conduct a veterinary and sanitary assessment of the quality of quail meat for feeding NDC. The object of study were the quails of the Pharaoh breed, at the age of 24 were divided into two groups: experimental and control 30 heads each. The birds were kept in cages with free access to food and water. Quails of the experimental group were added to drinking water feed additive "Nanocerium" at a dose of 8.6 mg per liter of drinking water. Nanocerium feed additive is an aqueous dispersion of NDC with average nanoparticle sizes of 2–7 nm. Antemortem examination of quails of both groups revealed a satisfactory clinical condition of birds. The average weight of the gut carcass of quails of the experimental group was higher by 8.3% compared to the control. Examination of 20 carcasses of quails showed that they can be classified as first class. According to organoleptic parameters, quail meat is of good quality in veterinary and sanitary terms. Microbiological studies of quail meat indicate no effect of NDC in the applied doses on its bacterial contamination. Chemical parameters of meat (pH, aminoammonia nitrogen, volatile fatty acids during storage in the refrigerator) (5 days, t = 4–5 ° C) tended to increase and were within the normal range for fresh product. Tissue in quails of both groups was not detected. The biological value of quail meat in both groups was identical and no toxicity. Tasting evaluation of the broth and meat showed that NDC did not affect the studied taste. The obtained results show that the quails that received the feed additive "Nanocerium" with water according to the indicators of veterinary and sanitary examination are of good quality, which allows to use it in human food without restrictions. Key words: poultry, nanocerium, organoleptic evaluation, microbial contamination, biological value, tasting evaluation.

Spectroscopic and structural properties of CeO2 nanocrystals doped with La3+, Nd3+ and modified on their surface with Ag nanoparticles

The purpose of this work is to present our efforts focused on applications of chemical synthesis of nanocrystalline cerium dioxide (CeO2) powders doped with La3+ ions and CeO2:Nd3+ modified, on their surface, with Ag nanoparticles (NPs). The synthesized powders were examined by X-ray powder diffraction (XRD), absorption, emission spectroscopy, scanning electron (SEM) and atomic force microscopy (AFM). The relations between crystallographic properties and stability of CeO2 compounds doped by La ions and surface-modified by Ag were studied. XRD patterns revealed that all studied samples are single-phase and crystallized in the cubic fluorite-type structure, in space group Fm-3m. The average crystallite sizes estimated by Rietveld method of series: La-doped CeO2 were in the range of 7–14 nm, and CeO2:1%Nd3+/n-Ag (n: 1- 5wt.%) were found to be in the range of 29–34 nm, respectively. The lattice parameter a for La-doped CeO2 powders varying from 5.416 to 5.482 Å with increasing content of La3+ ions from 0 to 20wt.%, respectively. For series of CeO2:Nd3+/n-Ag materials lattice parameter a was at the same level and in accordance with the standard value a0 = 5.411 Å (ICDD - 43-1002). The SEM and AFM observations depicted the grainy structure of all obtained CeO2-powder samples. The estimated grain size ranged from 50 to 500 nm. The diverse grain shapes and packing was remarked in the samples. According to our knowledge, the relationship between the structural, spectroscopic and morphological characteristics of CeO2 samples was presented in this work for the first time.

Вплив наночастинок СеО2 на проростання насіння та синтез фенолів у проростках ялини європейської

Modern technologies make it possible to obtain nanoparticles of biogenic metals for use as an additional source of micronutrient for plants. However, the complexity of mass application of nanosized metal particles and their oxides is due to the significant differences in physicochemical properties of nanocrystalline structures which are dependent on production technology, nanoparticle size, surface charge (-potential), and stabilization methods. The biocompatibility and nature of nanoparticles has an impact on living organisms. Regarding the effectiveness and feasibility of using cerium dioxide nanoparticles in crop practice, there is no definitive conclusion. Due to difficulty in the preparation of planting material for seedlings of conifers, the study of the effect of nanocrystalline cerium dioxide on plants is not well researched. The aim of our research was to study the effect of nanocrystalline cerium dioxide solution on the germination of spruce seeds and then to evaluate its effect on the synthesis of phenols as components of the antioxidant system within seedlings. The research used methods for determining the germination energy and seed similarities. Other methods used in this research were determining the content of phenolic compounds, flavonoids, and phenolic antioxidants. The results showed that nanocrystalline cerium dioxide in a concentration of solution from 0.1 to 1.0 mg/mL stimulates the germination of spruce seeds. Under the influence of nanoparticles at a concentration of 0.1 mg/L in the tissues of spruce seedlings increases the content of phenolic compounds. The increase in antioxidant activity of phenols in seedling tissues while decreasing their total amount at a concentration of nanocrystalline cerium dioxide from 0.5 to 1.0 mg/L occurs when increasing the total pool of flavonoids, which are determined by high antioxidant activity. Nanocrystalline cerium dioxide is a promising material for stimulating germination energy and on the overall germination of spruce seeds.

Успішне кріоконсервування фібробластів за рахунок зниження концентрації ДМСО та додавання нанокристалічного діоксиду церію

Успішне кріоконсервування фібробластів за рахунок зниження концентрації ДМСО та додавання нанокристалічного діоксиду церію

Comparative Analysis of Sun Protection Characteristics of Nanocrystalline Cerium Dioxide

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.

Single‐step densification of nanocrystalline CeO2 by the cold sintering process

AbstractThis study reports the successful single‐step cold sintering of nanocrystalline cerium dioxide (CeO2) at temperatures ranging from 250°C to 400°C under 500 MPa, using molten hydroxides flux solvents. CeO2 ceramics obtained were 82 to 91% of the theoretical density. Structural and microstructural investigations of the as‐cold sintered CeO2 ceramics were conducted to further understand this new approach to cold sinter ceramics. Electrical conductivity measured by two‐point AC impedance demonstrated an activation energy for grain conductivity of 0.49 eV, with impedance spectra characteristic of nanoscale CeO2.

Effectiveness of nanocrystalline cerium dioxide for secondary prevention of inflammatory periodontal diseases in young individuals with obesity

Obesity is a non-infectious pandemic, largely associated with oral diseases development. Oxidative stress is one of the crucial mechanisms in the development of inflammatory periodontal diseases in obesity. Nanomedicine is a highly promising to alleviate pbesity and associated conditions. The aim was to study the influence of cerium dioxide nanoparticles on periodontal tissues of patients with diverse values of BMI and assess changes of periodontal tissues. We included 125 young Ukrainian individuals of both sexes (18-22 years old), divided into four groups according to Body mass index (BMI). Initial oral status was detected with index assessment that include the determination of caries intensity by DMFT index, oral hygiene determination (Green-Vermillion index), periodontal tissues (Rateitchak index), PMA (Parma), CPI (Leus), PBI (Saxer and Muhlemann). The periodontograma was completed for all patients. After the initial checkup all examined patients with generalized catarrhal gingivitis were randomly divided into two groups: treated with «Cerera» (the active substance is nanoparticles of cerium dioxide 2-7 nm in concentration of 140 mcg/ml that were stabilized with sodium citrate) per os for 10 drops every day in the morning diluted in 50 ml of water for 10 days and controls. Patients with 1st and 2nd degree obesity have a significantly higher grade of periodontal alteration compared with normal BMI and overweight (values of CPI 1.7±0.9 and 1.66±0.12 vs 1.33±0.11 and 1.42±0.11 respectively). The intensity and the prevalence of gingiva inflammation assessed by PMA and PBI index were significantly higher in obese individuals. In all overweight patients the level of catalase activity was significantly lower than in patients with normal values of BMI. The administration of «Cerera» significantly increased the activity of catalase regardless of BMI, significantly changed the values of gingival inflammation indexes; the severity of inflammatory process became less intensive vs baseline (determined by PBI values before 17.6%±2.1 and 7.8%±2.1 after treatment; in the 4th group the values of PBI had declined significantly by 1.6 times). After the 10 days administration of «Cerera» the content of GAG and fucose in oral liquid of all obese individuals significantly decreased; lipid oxidation parameters decreased in excessive obesity: TBA-active products levels in patients with BMI 35.00-39.99 kg/сm2 dropped down from 53.9±2.11 μmol/L to 47.43±2.29 μmol/L. Cerium dioxide nanoparticles demonstrate high effectiveness against inflammatory changes in periodontal tissues in obese patients. The mechanisms of action of cerium dioxide nanoparticles in the periodontal structures are needed to be precisely determined in further studies.

Morphometry Results of Formed Osteodefects When Using Nanocrystalline CeO2 in the Early Stages of Regeneration.

This paper studies of the use of nanocrystalline cerium dioxide with artificially formed bone tissue defects. The results of morphometry confirmed the antialterative effect in the early stages of the reparative process of damaged bone tissue. When using calcium hydroxide with nanodispersed cerium dioxide, the nature of osteogenesis should be characterized as activated. In case of damage to the dentin of the roots of the teeth, dentinogenesis in presence of CeO2 occurs with the formation of a combined dentin and bone regenerates. Little or no studies of dentinogenesis in presence of CeO2 were performed by other researchers.

Cerium Oxalate Morphotypes: Synthesis and Conversion into Nanocrystalline Oxide.

Cerium dioxide is a scientifically and technologically important material with a wide range of potential applications, particularly in solid oxide fuel cells and catalysis. Herein, we report a study focusing on the synthesis of nanocrystalline cerium dioxide via thermal decomposition of the oxalate salt. Simply by changing reaction conditions (temperature, concentration, acidity, strike) during the precipitation of the cerium solution with oxalic acid, we were able to obtain different morphologies. The main reaction parameters were mapped and linked to the morphology of the final products. Additionally, it was proved that oxalate precipitation is a robust reaction proceeding at relatively extreme contitions. Moreover, the conversion of cerium oxalate to nanocrystalline oxide was followed to monitor the progress of the reaction, the texture evolution, and the grain growth. The results showed that, for unvaried heating cycle, the grain size of converted material is linked to morphology. The thinner was the original microcrystal the smaller were the CeO2 nanocrystals after calcination. In addition, the grains were found smaller near the edges of the ex-oxalate microcrystals. In both cases, this behavior results from asymmetrical limitations of diffusion during grain growth.

Oxygen diffusion and vacancy migration thermally-activated govern high-temperature magnetism in ceria

Several experimental works currently demonstrate that metallic nano-oxides and carbon nanomaterials expected to be diamagnets, in fact, behave as ferromagnets at room temperature. More than scientifically intriguing, this unconventional and unexpected ferromagnetism pave the way for innovation products and novel nanotechnological applications, gathering the magnetism to interesting functionalities of these nanomaterials. Here, we investigate the non-conventional ferromagnetism observed at high temperatures in nanocrystalline cerium dioxide (CeO2or nanoceria) thin films that are optically transparent to visible light. Nanoceria exhibits several concrete applications in catalytic processes, photovoltaic cells, solid-state fuel cells, among others, which are mostly due to natural presence of oxygen vacancies and easy migration of the oxygen through the structure. The ferromagnetism in non-stoichiometric nanocrystaline ceria can be consistently described by ab initio electronic structure calculations, which support that oxygen vacancies cause the formation of magnetic moments and can provide a robust interconnectivity within magnetic polarons theoretical framework. Additionally, we present a conceptual model to account the oxygen transport to the non-conventional ferromagnetism at temperatures well above room temperature. The approach is complementary to the thermally-activated effective transfers of charge and spin around oxygen vacancy centers.