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Roots play an important role in plant growth, including providing essential mechanical support, water uptake, and nutrient absorption. Nanomaterials play a positive role in improving plant root development, but there is limited knowledge of how nanomaterials affect lateral root (LR) formation. Poly (acrylic) acid coated nanoceria (cerium oxide nanoparticles, PNC) are commonly used to improve plant stress tolerance due to their ability to scavenge reactive oxygen species (ROS). However, its impact on LR formation remains unclear. In this study, we investigated the effects of PNC on LR formation in Arabidopsis thaliana by monitoring ROS levels and Ca2+ distribution in roots. Our results demonstrate that PNC significantly promote LR formation, increasing LR numbers by 26.2%. Compared to controls, PNC-treated Arabidopsis seedlings exhibited reduced H2O2 levels by 18.9% in primary roots (PRs) and 40.6% in LRs, as well as decreased O 2 · − levels by 47.7% in PRs and 88.5% in LRs. When compared with control plants, Ca2+ levels were reduced by 35.7% in PRs and 22.7% in LRs of PNC-treated plants. Overall, these results indicate that PNC could enhance LR development by modulating ROS and Ca2+ levels in roots. In this study, we showed that cerium oxide nanoparticles (PNC) promoted lateral root formation in Arabidopsis thaliana by modulating reactive oxygen species and Ca2+ distribution in both primary and lateral roots. Results indicated that applying PNC to plants have potential to improve the development of root system and thus overall plant growth performance. Adopting nanobiotechnology to stimulate plant root system may be beneficial to sustainable agriculture. [ABSTRACT FROM AUTHOR]

Abstract Cerium oxide nanoparticles possess unique properties that make them promising candidates in various fields, including cancer treatment. Among the proposed synthesis methods for CNPs, biosynthesis using natural extracts, offers an eco-friendly and convenient approach for producing CNPs, particularly for biomedical applications. In this study, a novel method of biosynthesis using the aqueous extract of Eucalyptus camaldulensis leaves was used to synthesize CNPs. Scanning electron microscopy and Transmission electron microscopy (TEM) techniques revealed that the synthesized CNPs exhibit a flower-like morphology. The particle size of CNPs obtained using Powder X-ray diffraction peaks and TEM as 13.43 and 39.25 nm. Energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy confirmed the effect of biomolecules during the synthesis process and the formation of CNPs. The cytotoxicity of biosynthesized samples was evaluated using the MTT method demonstrating the potential of these samples to inhibit MCF-7 cancerous cells. The viability of the MCF-7 cell line conducted by live/dead imaging assay confirmed the MTT cytotoxicity method and indicated their potential to inhibit cancerous cells. Furthermore, the successful uptake of CNPs by MCF-7 cancer cells, as demonstrated by confocal microscopy, provides evidence that the intracellular pathway contributes to the anticancer activity of the CNPs. In general, results indicate that the biosynthesized CNPs exhibit significant cytotoxicity against the MCF-7 cancerous cell line, attributed to their high surface area.

Three-dimensional (3D) bioprinting has made it possible to fabricate structures with intricate morphologies and architectures, which is considered difficult to do when using other conventional techniques like electrospinning. Although the 3D printing of thermoplastics has seen a huge boom in the past few years, it has been challenging to translate this technology to cell-based printing. A major limitation in bioprinting is the lack of inks that allow for the printing of 3D structures that meet the biological requirements of a specific organ or tissue. A bioink is a viscous polymer solution that cells are incorporated into before printing. Therefore, a bioink must have specific characteristics to ensure both good printability and biocompatibility. Despite the progress that has been made in bioprinting, achieving a balance between these two properties has been difficult. In this work, we developed a multimodal bioink that serves as both a cell carrier and a free radical scavenger for treating peripheral nerve injury. This bioink comprises poly-(vinyl alcohol) (PVA) and cerium oxide nanoparticles (also called nanoceria (NC)) and was developed with a dual crosslinking method that utilizes citric acid and sodium hydroxide. By employing this dual crosslinking method, good printability of the bioink and shape fidelity of the bioprinted structure were achieved. Additionally, a cell viability study demonstrated that the cells remained compatible and viable even after they underwent the printing process. The combination of this PVA/NC bioink and the dual crosslinking method proved to be effective in enhancing printability and cell biocompatibility for extrusion-based bioprinting applications. [ABSTRACT FROM AUTHOR]

Background Nanotechnology has shown a remarkable progress nevertheless, there is a growing concern about probable neurotoxic and neurodegenerative effects due to NPs exposure. Various toxicological and epidemiological studies reported that the brain is a main target for ultrafine particles. Brain inflammation is considered as a possible mechanism that can participate to neurotoxic and neurodegenerative effects. Whether nanoparticles (NPs) may produce neurotoxicity and promote neurodegenerative is largely unstudied. The present study was done to investigate whether intranasal and intra-peritoneal exposure to cerium oxide nanoparticles (CeO2NPs, nanoceria (NC)) could cause neurotoxicity and neurodegenerative changes in the brain tissue through conducting some behavioral tests, biochemical evaluation, histopathological examinations of brain hippocampus and gene expressions. Method Fifteen mice were separated into 3 equal groups. In group (I) "control group", mice were received distilled water orally and kept as a control group. Mice in the group (II) "NC I/P group" were injected i.p with cerium oxide nanoparticles at a dose of 40 mg/kg b.wt, twice weekly for 3 weeks. In group (III) "NC I/N group" mice were received nanoceria intranasally (40 mg/kg b.wt), twice weekly for 3 weeks. Results Exposure to nanceria resulted in oxidative damage in brain tissue, a significant increase in malondialdehyde (MDA) and acetylcholinestrase (AchE) levels, significant decrease in reduced glutathione (GSH) concentration, upregulation in the apoptosis-related genes (c-Jun: c-Jun N-terminal kinases (JNKs), c-Fos: Fos protooncogene, AP-1 transcription factor subunit, c-Myc: c-myelocytomatosis oncogene product or MYC protooncogene, bHLH transcription factor), locomotor and cognitive impairment in mice but the effect was more obvious when nanoceria adminstred intraperitoneally. Conculsion Nanoceria cause oxidative damage in brain tissue of mice when adminstred nanoceria intraperitoneally more than those received nanoceria intranasal. [ABSTRACT FROM AUTHOR]

Cerium oxide nanoparticles possess unique properties that make them promising candidates in various fields, including cancer treatment. Among the proposed synthesis methods for CNPs, biosynthesis using natural extracts, offers an eco-friendly and convenient approach for producing CNPs, particularly for biomedical applications. In this study, a novel method of biosynthesis using the aqueous extract of Eucalyptus camaldulensis leaves was used to synthesize CNPs. Scanning electron microscopy and Transmission electron microscopy (TEM) techniques revealed that the synthesized CNPs exhibit a flower-like morphology. The particle size of CNPs obtained using Powder X-ray diffraction peaks and TEM as 13.43 and 39.25 nm. Energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy confirmed the effect of biomolecules during the synthesis process and the formation of CNPs. The cytotoxicity of biosynthesized samples was evaluated using the MTT method demonstrating the potential of these samples to inhibit MCF-7 cancerous cells. The viability of the MCF-7 cell line conducted by live/dead imaging assay confirmed the MTT cytotoxicity method and indicated their potential to inhibit cancerous cells. Furthermore, the successful uptake of CNPs by MCF-7 cancer cells, as demonstrated by confocal microscopy, provides evidence that the intracellular pathway contributes to the anticancer activity of the CNPs. In general, results indicate that the biosynthesized CNPs exhibit significant cytotoxicity against the MCF-7 cancerous cell line, attributed to their high surface area. [ABSTRACT FROM AUTHOR]

Here, we first synthesized carbon dots (CDs) from taurine and then a nanohybrid with ceria (CeO2) nanoparticles using thermal decomposition method for checking their antineoplastic efficacy against human triple negative mammary carcinoma cells, MDA-MB-231. The in vitro study demonstrated significant dose-dependent antineoplastic activity of the nanohybrids within a range of concentration from 10 to 50 μg/mL after 48 h of treatment. The cellular morphology analysis clearly depicted substantial amount of cell death which seems to stem from increased intracellular reactive oxygen species (ROS) production. However, the maximum anticancer activity of the nanohybrid as compared to bare CDs and CeO2 is supposed to be due to the combined anticancer effect of both CDs and CeO2 (a well-established antitumor agent). Further we have performed molecular docking study to reveal the anticancer mechanism of CDs which exhibited high binding capacity towards several proapoptotic and antiapoptotic protein molecules. The binding affinity values were found to be – 8.7 kcal/mol, – 7.9 kcal/mol, – 9.6 kcal/mol, – 9.5 kcal/mol, – 12 kcal/mol and – 11.1 kcal/mol for BAD, BCl-2, p53, Caspase-8, Caspase-9 and Caspase-3 respectively. Taken together, our synthesized CDs-CeO2 nanohybrid could be thought as a potential anticarcinogenic option in the field of breast cancer therapeutics.

Their unique physicochemical properties and multi-enzymatic activity make CeO2 nanoparticles (CeO2 NPs) the most promising active component of the next generation of theranostic drugs. When doped with gadolinium ions, CeO2 NPs constitute a new type of contrast agent for magnetic resonance imaging, possessing improved biocatalytic properties and a high level of biocompatibility. The present study is focused on an in-depth analysis of the enzyme-like properties of gadolinium-doped CeO2 NPs (CeO2:Gd NPs) and their antioxidant activity against superoxide anion radicals, hydrogen peroxide, and alkylperoxyl radicals. Using an anion-exchange method, CeO2:Gd NPs (~5 nm) with various Gd-doping levels (10 mol.% or 20 mol.%) were synthesized. The radical-scavenging properties and biomimetic activities (namely SOD- and peroxidase-like activities) of CeO2:Gd NPs were assessed using a chemiluminescent method with selective chemical probes: luminol, lucigenin, and L-012 (a highly sensitive luminol analogue). In particular, gadolinium doping has been shown to enhance the radical-scavenging properties of CeO2 NPs. Unexpectedly, both bare CeO2 NPs and CeO2:Gd NPs did not exhibit SOD-like activity, acting as pro-oxidants and contributing to the generation of reactive oxygen species. Gadolinium doping caused an increase in the pro-oxidant properties of nanoscale CeO2. At the same time, CeO2:Gd NPs did not significantly inhibit the intrinsic activity of the natural enzyme superoxide dismutase, and CeO2:Gd NPs conjugated with SOD demonstrated SOD-like activity. In contrast to SOD-like properties, peroxidase-like activity was observed for both bare CeO2 NPs and CeO2:Gd NPs. This type of enzyme-like activity was found to be pH-dependent. In a neutral medium (pH = 7.4), nanoscale CeO2 acted as a prooxidant enzyme (peroxidase), while in an alkaline medium (pH = 8.6), it lost its catalytic properties; thus, it cannot be regarded as a nanozyme. Both gadolinium doping and conjugation with a natural enzyme were shown to modulate the interaction of CeO2 NPs with the key components of redox homeostasis. [ABSTRACT FROM AUTHOR]

The therapeutic effectiveness of anticancer drugs, including nanomedicines, can be enhanced with active receptor‐targeting strategies. Epidermal growth factor receptor (EGFR) is an important cancer biomarker, constitutively expressed in sarcoma patients of different histological types. The present work reports materials and in vitro biomedical analyses of silanized (passive delivery) and/or EGF‐functionalized (active delivery) ceria nanorods exhibiting highly defective catalytically active surfaces. The EGFR‐targeting efficiency of nanoceria was confirmed by receptor‐binding studies. Increased cytotoxicity and reactive oxygen species (ROS) production were observed for EGF‐functionalized nanoceria owing to enhanced cellular uptake by HT‐1080 fibrosarcoma cells. The uptake was confirmed by TEM and confocal microscopy. Silanized nanoceria demonstrated negligible/minimal cytotoxicity toward healthy MRC‐5 cells at 24 and 48 h, whereas this was significant at 72 h owing to a nanoceria accumulation effect. In contrast, considerable cytotoxicity toward the cancer cells was exhibited at all three times points. The ROS generation and associated cytotoxicity were moderated by the equilibrium between catalysis by ceria, generation of cell debris, and blockage of active sites. EGFR‐targeting is shown to enhance the uptake levels of nanoceria by cancer cells, subsequently enhancing the overall anticancer activity and therapeutic performance of ceria. [ABSTRACT FROM AUTHOR]

With the pronounced increase in nanotechnology, it is likely that biological systems will be exposed to excess nanoparticles (NPs). Cerium oxide nanoparticles (CeO2 NPs) are among the most abundantly produced nanomaterials in the world. Their widespread use raises fundamental questions related to the accumulation in the environment and further interactions with living organisms, especially plants. NPs present in either soil or soilless environments are absorbed by the plant root systems and further transported to the aboveground parts. After entering the cytoplasm, NPs interact with chloroplast, nucleus, and other structures responsible for metabolic processes at the cellular level. In recent years, several studies have shown the impact of nanoceria on plant growth and metabolic processes. Research performed on different plants has shown a dual role for CeO2 NPs. The observed effects can be positive or negative and strongly depend on the plant species, characterization, and concentrations of NPs. This review describes the impact of root-applied CeO2 NPs on plant growth, photosynthesis, metal homeostasis, and parameters of induced oxidative stress. [ABSTRACT FROM AUTHOR]

Aim: Cerium oxide, particularly in nanoparticle form (nanoceria), has been investigated for biomedical applications as a promising new agent for treating several pathologies. The aim of the present study was to characterize the pharmacologic effects of nanoceria in an animal model of chronic kidney disease. Methods: We created the chronic kidney disease animal model by feeding rats a 0.25% adenine diet. Male Wistar rats were divided into five groups: normal diet, 0.25% adenine diet, or adenine diet containing three different doses or durations of nanoceria treatment. Blood was collected weekly from the tail veins of each rat and analyzed for renal function markers. After 5 weeks, various biochemical markers in serum, plasma, and urine were also analyzed. Results: In the adenine‐treated group, body weight was significantly decreased, and the kidneys lost much of their healthy reddish color and became lumpy and white in appearance. In addition, levels of serum creatinine, blood urea nitrogen, and plasma uremic toxins were significantly increased in adenine‐treated rats compared with controls. Renal functional and structural damage in adenine diet model rats tended to be ameliorated by nanoceria ingestion. The high‐dose cerium‐treated group maintained reddish areas in the kidneys, and the increases in biomarker levels of creatinine, blood urea nitrogen, and inorganic phosphorus were markedly reduced, regardless of treatment duration. Conclusions: Ingestion of nanoceria may be effective for improving or preventing renal damage caused by adenine. Geriatr Gerontol Int 2024; 24: 88–95. [ABSTRACT FROM AUTHOR]

Breast cancer poses a significant health concern due to its increasing prevalence and mortality rates. Hence, prompt action is needed to develop innovative therapeutic interventions, as conventional treatments exhibit severe adverse effects and have limited efficacy. This study aims to develop an innovative therapeutic intervention for breast cancer using biosynthesized nanoceria. Nanoceria has gained significant importance in the medicinal field due to its biocompatibility, dual capabilities as both antioxidant and prooxidant, and specific cytotoxicity towards cancer cells. Herein, nanoceria was biosynthesized using Echinochloa frumentaceae grain extract (EFNC) due to its eco-friendly and cost-efficient nature, and it was systematically investigated using standard characterization techniques. Furthermore, their anticancer efficacy against MCF-7 breast cancer cell lines was studied using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) cell viability assay, and the occurrence of apoptosis was determined using acridine orange/ethidium bromide (AO/EtBr) staining. Significantly, EFNC exhibited superior anticancer efficacy even at lower concentrations (10 µg/mL), and the IC50 value was found at 47.32 µg/mL. In addition, the observed bright green and orange-red fluorescence, along with fragmented/condensed chromatin features in AO/EtBr staining clearly indicated that the EFNC caused cell death through the apoptotic route. One potential factor contributing to the observed anticancer effectiveness of EFNC could be its prooxidant properties within cancer cells. These properties ultimately enhanced oxidative stress, induced the accumulation of reactive oxygen species (ROS), and led to apoptosis. Hence, the in vitro analysis substantiated the significant anticancer efficacy of EFNC, suggesting its potential utility as a promising therapeutic agent in anticancer treatment. These findings pave the way for further exploration and development of EFNC as a valuable candidate for addressing cancer-related challenges.

The purpose of this study was to investigate the antimicrobial activity of citrate-stabilized sols of cerium oxide nanoparticles at different concentrations via different microbiological methods and to compare the effect with the peroxidase activity of nanoceria for the subsequent development of a regeneration-stimulating medical and/or veterinary wound-healing product providing new types of antimicrobial action. The object of this study was cerium oxide nanoparticles synthesized from aqueous solutions of cerium (III) nitrate hexahydrate and citric acid (the size of the nanoparticles was 3–5 nm, and their aggregates were 60–130 nm). Nanoceria oxide sols with a wide range of concentrations (10−1–10−6 M) as well as powder (the dry substance) were used. Both bacterial and fungal strains (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Proteus vulgaris, Candida albicans, Aspergillus brasielensis) were used for the microbiological studies. The antimicrobial activity of nanoceria was investigated across a wide range of concentrations using three methods sequentially; the antimicrobial activity was studied by examining diffusion into agar, the serial dilution method was used to detect the minimum inhibitory and bactericidal concentrations, and, finally, gas chromatography with mass-selective detection was performed to study the inhibition of E. coli's growth. To study the redox activity of different concentrations of nanocerium, we studied the intensity of chemiluminescence in the oxidation reaction of luminol in the presence of hydrogen peroxide. As a result of this study's use of the agar diffusion and serial dilution methods followed by sowing, no significant evidence of antimicrobial activity was found. At the same time, in the current study of antimicrobial activity against E. coli strains using gas chromatography with mass spectrometry, the ability of nanoceria to significantly inhibit the growth and reproduction of microorganisms after 24 h and, in particular, after 48 h of incubation at a wide range of concentrations, 10−2–10−5 M (48–95% reduction in the number of microbes with a significant dose-dependent effect) was determined as the optimum concentration. A reliable redox activity of nanoceria coated with citrate was established, increasing in proportion to the concentration, confirming the oxidative mechanism of the action of nanoceria. Thus, nanoceria have a dose-dependent bacteriostatic effect, which is most pronounced at concentrations of 10−2–10−3 M. Unlike the effects of classical antiseptics, the effect was manifested from 2 days and increased during the observation. To study the antimicrobial activity of nanomaterials, it is advisable not to use classical qualitative and semi-quantitative methods; rather, the employment of more accurate quantitative methods is advised, in particular, gas chromatography–mass spectrometry, during several days of incubation. [ABSTRACT FROM AUTHOR]

The motility, health quality, and membrane disorders of spermatozoa are adversely affected during the process of semen cryopreservation due to the over-production of reactive oxygen species (ROS). Cerium oxide nanoparticles (CeO 2 NPs) possess properties to scavenge ROS either by mimicking specific antioxidants or by enhancing the activities of antioxidant enzymes. Therefore, we aimed at evaluating the effects of adding the CeO 2 NPs in the TRIS-citrate-yolk extender on in-vitro antioxidant enzyme activities, spermatozoa quality attributes, and in-vivo fertility of post-thaw Beetal buck spermatozoa. The CeO 2 NPs were prepared and characterized (UV-spectrophotometry, FTIR, and XRD). Semen samples, collected from bucks (n = 5), were distributed into five aliquots and diluted in an extender containing increasing concentrations of nanoparticles (0 μg/ml, called the control group, 25 μg/mL, 50 μg/mL, 75 μg/mL, and 100 μg/mL). At post-thaw, spermatozoa were evaluated for the above-mentioned attributes and the pregnancy rate by inseminating Beetal does (n = 252). Results demonstrated that CeO 2 NPs mitigated the detrimental effects of cryopreservation as ROS production and lipid peroxidation were lower (P < 0.001) in the 25, 50, and 75 μg/mL CeO 2 NPs-added groups compared to the control and 100 μg/ml CeO 2 NPs-added group. The addition of 25 μg/mL CeO 2 NPs improved (P < 0.001) the activities of superoxide dismutase, catalase, and peroxidase and the concentration of reduced glutathione (P < 0.001) compared to the other groups. In terms of sperm kinematics and velocity parameters, the groups added with the 25 and 50 μg/mL CeO 2 NPs exhibited higher total motility (P < 0.001), sperm progressive motility (P = 0.003), and rapid velocity (P < 0.001). The group added with the 50 μg/mL CeO 2 NPs had the highest (P = 0.04) average path velocity. The groups added with the 25 and 50 μg/mL CeO 2 NPs also exhibited higher plasma membrane integrity (P = 0.003), acrosomal integrity, and viability (P < 0.001) compared to the control group. The DNA integrity was also higher (P < 0.001) in all the CeO 2 NPs-added groups. The pregnancy rate was higher (P = 0.003) in the 25 (51.92 %) and 50 μg/mL CeO 2 NPs (58.33 %) groups compared to the other groups. Conclusively, our findings suggest that the inclusion of cerium oxide nanoparticles in the TRIS-citrate-yolk freezing extender can reduce the occurrence of cryopreservation-induced damages to Beetal's buck spermatozoa and ultimately enhance the pregnancy rate in does. • Cerium oxide nanoparticles in cryo-diluent, were compared for post-thaw redox potentials, sperm quality and pregnancy in buck spermatozoa. • Five concentrations of cerium oxide nanoparticles (0 μg/ml, 25 μg/mL, 50 μg/mL, 75 μg/mL, and 100 μg/mL) were compared. • Cerium oxide nanoparticles ameliorated the cryopreservation-induced damages to Beetal's buck spermatozoa and ultimately enhanced the pregnancy rate. [ABSTRACT FROM AUTHOR]

Cerium atoms on the surfaces of nanoceria (i.e., cerium oxide in the form of nanoparticles) can store or release oxygen, cycling between Ce3+ and Ce4+; therefore, they can cause or relieve oxidative stress within living systems. Nanoceria dissolution occurs in acidic environments. Nanoceria stabilization is a known problem even during its synthesis; in fact, a carboxylic acid, namely citric acid, is used in many synthesis protocols. Citric acid adsorbs onto nanoceria surfaces, limiting particle formation and creating stable dispersions with extended shelf life. To better understand factors influencing the fate of nanoceria, its dissolution and stabilization have been previously studied in vitro using acidic aqueous environments. Nanoceria agglomerated in the presence of some carboxylic acids over 30 weeks, and degraded in others, at pH 4.5 (i.e., the pH value in phagolysosomes). Plants release carboxylic acids, and cerium carboxylates are found in underground and aerial plant parts. To further test nanoceria stability, suspensions were exposed to light and dark conditions, simulating plant environments and biological systems. Light induced nanoceria agglomeration in the presence of some carboxylic acids. Nanoceria agglomeration did not occur in the dark in the presence of most carboxylic acids. Light initiates free radicals generated by ceria nanoparticles. Nanoceria completely dissolved in the presence of citric, malic, and isocitric acid when exposed to light, attributed to nanoceria dissolution, release of Ce3+ ions, and formation of cerium coordination complexes on the ceria nanoparticle surface that inhibit agglomeration. Key functional groups of carboxylic acids that prevented nanoceria agglomeration were identified. A long carbon chain backbone containing a carboxylic acid group geminal to a hydroxy group in addition to a second carboxylic acid group may optimally complex with nanoceria. The results provide mechanistic insight into the role of carboxylic acids in nanoceria dissolution and its fate in soils, plants, and biological systems.

Nonalcoholic fatty liver disease (NAFLD) describes a spectrum of liver abnormalities, from benign steatosis to nonalcoholic steatohepatitis (NASH). Because of their antioxidant capabilities, CeNPs have sparked a lot of interest in biological applications. This review evaluated the effectiveness of CeNPs in NAFLD evolution through in vivo and in vitro studies. Databases such as MEDLINE, EMBASE, Scopus, and Web of Science were looked for studies published between 2012 and June 2023. Quality was evaluated using PRISMA guidelines. We looked at a total of nine primary studies in English carried out using healthy participants or HepG2 or LX2 cells. Quantitative data such as blood chemical markers, lipid peroxidation, and oxidative status were obtained from the studies. Our findings indicate that NPs are a possible option to make medications safer and more effective. In fact, CeNPs have been demonstrated to decrease total saturated fatty acids and foam cell production (steatosis), reactive oxygen species production and TNF-α (necrosis), and vacuolization in hepatic tissue when used to treat NAFLD. Thus, CeNP treatment may be considered promising for liver illnesses. However, limitations such as the variation in durations between studies and the utilization of diverse models to elucidate the etiology of NAFLD must be considered. Future studies must include standardized NAFLD models. [ABSTRACT FROM AUTHOR]

In the ongoing search for practical uses of rare-earth metal nanoparticles, cerium dioxide nanoparticles (nanoceria) have received special attention. The purpose of this research was to study the biomedical effects of nanocrystalline forms of cerium oxide obtained by different synthesis schemes and to evaluate the effect of different concentrations of nanoceria (from 10−2 to 10−6 M) on cells involved in the regeneration of skin cell structures such as fibroblasts, mesenchymal stem cells, and keratinocytes. Two different methods of nanoceria preparation were investigated: (1) CeO-NPs-1 by precipitation from aqueous solutions of cerium (III) nitrate hexahydrate and citric acid and (2) CeO-NPs-2 by hydrolysis of ammonium hexanitratocerate (IV) under conditions of thermal autoclaving. According to the X-ray diffraction, transmission electron microscopy, and dynamic light scattering data, CeO2-1 consists of individual particles of cerium dioxide (3–5 nm) and their aggregates with diameters of 60–130 nm. CeO2-2 comprises small aggregates of 8–20 nm in diameter, which consist of particles of 2–3 nm in size. Cell cultures of human fibroblasts, human mesenchymal stem cells, and human keratinocytes were cocultured with different concentrations of nanoceria sols (10−2, 10−3, 10−4, 10−5, and 10−6 mol/L). The metabolic activity of all cell types was investigated by MTT test after 48 and 72 h, whereas proliferative activity and cytotoxicity were determined by quantitative cell culture counting and live/dead test. A dependence of biological effects on the method of nanoceria preparation and concentration was revealed. Data were obtained with respect to the optimal concentration of sol to achieve the highest metabolic effect in the used cell cultures. Hypotheses about the mechanisms of the obtained effects and the structure of a fundamentally new medical device for accelerated healing of skin wounds were formulated. The method of nanoceria synthesis and concentration fundamentally and significantly change the biological activity of cell cultures of different types—from suppression to pronounced stimulation. The best biological activity of cell cultures was determined through cocultivation with sols of citrate nanoceria (CeO-NPs-1) at a concentration of 10−3–10−4 M. [ABSTRACT FROM AUTHOR]

Synthetic chemical pesticides' nature, mode of action, and persistence have brought about debates regarding whether the end justifies the means. Lambda-cyhalothrin is an important insecticide for farmers and households, with great accessibility and excellent action against pests and disease-carrying insects. Like other pyrethroid pesticides, Lambda-cyhalothrin targets the nervous system of insects or pests. However, its fate in the environment, especially in water and living systems, has made it crucial to explore methods of treating or degrading its residues in the environment. The present study aimed to develop a suitable method for the photocatalytic degradation and removal of Lambda-cyhalothrin (LCY) from wastewater and agricultural runoff. The nanoceria were used under natural solar irradiation without applying any scavenger chemical or buffer. This was synthesized using a simple co-precipitation method using cerium nitrate hexahydrate as a precursor. The synthesized nanoceria were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared spectroscopy (FTIR) and particle size analysis. The average size of the particle was 27 nm. The photocatalytic degradation was conducted in batches with various pesticide concentrations exposed to different amounts of nanoceria. The initial and final concentrations of the LCY at each level were determined using Shimadzu UV spectroscopy. At optimum conditions, nanoceria was found to degrade and remove more than 63% of the initial pesticide concentration. This method can be suitable for degrading and removing pesticide residue from agricultural runoff (at source) and industrial effluents from synthetic pesticide industries. [ABSTRACT FROM AUTHOR]

Their unique physicochemical properties and multi-enzymatic activity make CeO2 nanoparticles (CeO2 NPs) the most promising active component of the next generation of theranostic drugs. When doped with gadolinium ions, CeO2 NPs constitute a new type of contrast agent for magnetic resonance imaging, possessing improved biocatalytic properties and a high level of biocompatibility. The present study is focused on an in-depth analysis of the enzyme-like properties of gadolinium-doped CeO2 NPs (CeO2:Gd NPs) and their antioxidant activity against superoxide anion radicals, hydrogen peroxide, and alkylperoxyl radicals. Using an anion-exchange method, CeO2:Gd NPs (~5 nm) with various Gd-doping levels (10 mol.% or 20 mol.%) were synthesized. The radical-scavenging properties and biomimetic activities (namely SOD- and peroxidase-like activities) of CeO2:Gd NPs were assessed using a chemiluminescent method with selective chemical probes: luminol, lucigenin, and L-012 (a highly sensitive luminol analogue). In particular, gadolinium doping has been shown to enhance the radical-scavenging properties of CeO2 NPs. Unexpectedly, both bare CeO2 NPs and CeO2:Gd NPs did not exhibit SOD-like activity, acting as pro-oxidants and contributing to the generation of reactive oxygen species. Gadolinium doping caused an increase in the pro-oxidant properties of nanoscale CeO2. At the same time, CeO2:Gd NPs did not significantly inhibit the intrinsic activity of the natural enzyme superoxide dismutase, and CeO2:Gd NPs conjugated with SOD demonstrated SOD-like activity. In contrast to SOD-like properties, peroxidase-like activity was observed for both bare CeO2 NPs and CeO2:Gd NPs. This type of enzyme-like activity was found to be pH-dependent. In a neutral medium (pH = 7.4), nanoscale CeO2 acted as a prooxidant enzyme (peroxidase), while in an alkaline medium (pH = 8.6), it lost its catalytic properties; thus, it cannot be regarded as a nanozyme. Both gadolinium doping and conjugation with a natural enzyme were shown to modulate the interaction of CeO2 NPs with the key components of redox homeostasis.

With the pronounced increase in nanotechnology, it is likely that biological systems will be exposed to excess nanoparticles (NPs). Cerium oxide nanoparticles (CeO2 NPs) are among the most abundantly produced nanomaterials in the world. Their widespread use raises fundamental questions related to the accumulation in the environment and further interactions with living organisms, especially plants. NPs present in either soil or soilless environments are absorbed by the plant root systems and further transported to the aboveground parts. After entering the cytoplasm, NPs interact with chloroplast, nucleus, and other structures responsible for metabolic processes at the cellular level. In recent years, several studies have shown the impact of nanoceria on plant growth and metabolic processes. Research performed on different plants has shown a dual role for CeO2 NPs. The observed effects can be positive or negative and strongly depend on the plant species, characterization, and concentrations of NPs. This review describes the impact of root-applied CeO2 NPs on plant growth, photosynthesis, metal homeostasis, and parameters of induced oxidative stress.

Oxidative stress induced reactive oxygen species has been implicated as the primary molecular mechanism in the pathogenesis of debilitating retinal diseases such as diabetic retinopathy, neovascularization and age-related macular degeneration. Nanoceria (cerium oxide nanoparticles) has recently received much attention, because of its superior and regenerative radical scavenging properties. This review focuses on retinal applications of nanoceria and functionalized nanoceria. Studies in animal models showed that nanoceria possess antioxidant, anti-inflammatory, anti-angiogenic, anti-apoptotic properties and preserves retinal morphology and prevents loss of retinal functions. Nanoceria have been tested in animal models of age-related macular degeneration and neovascularization and their efficacy have been shown to persist for a long time, without any collateral effects. To date, several pharmaceutical formulations of nanoceria have been developed for their prospective clinical ophthalmic applications such as chitosan coated nanoceria, nanoceria loaded into hydrogels, nanoceria embedded in wafers and contact lens and organosilane or polyethylene glycol functionalized nanoceria. Based on their nano size range, ocular permeation could be achieved to allow topical administration of nanoceria. PEGylation of nanoceria represents the key strategy to support eye drop formulation with enhanced corneal permeation, without altering chemical physical properties. Based on their excellent antioxidant properties, nano-size, safety and tolerability, PEGylated nanoceria represent a new potential therapeutic for the treatment.

Cerium oxide nanoparticles (CeO2NPs) have exceptional catalytic properties, rendering them highly effective in removing excessive reactive oxygen species (ROS) from biological environments, which is crucial in safeguarding these environments against radiation-induced damage. Additionally, the Ce atom's high Z number makes it an ideal candidate for utilisation as an X-ray imaging contrast agent. We herein show how the injection of albumin-stabilised 5 nm CeO2NPs into mice revealed substantial enhancement in X-ray contrast, reaching up to a tenfold increase at significantly lower concentrations than commercial or other proposed contrast agents. Remarkably, these NPs exhibited prolonged residence time within the target organs. Thus, upon injection into the tail vein, they exhibited efficient uptake by the liver and spleen, with 85% of the injected dose (%ID) recovered after 7 days. In the case of intratumoral administration, 99% ID of CeO2NPs remained within the tumour throughout the 7-day observation period, allowing for observation of disease dynamics. Mass spectrometry (ICP-MS) elemental analysis confirmed X-ray CT imaging observations. [ABSTRACT FROM AUTHOR]

In this study, a novel method using Ferula gummosa gums as a capping agent was used to synthesize the nanoceria for the first time. The method was economical and performed at room temperature. Furthermore, it was coated with gold (Au/nanoceria) and fully characterized using X-ray powder diffraction (XRD), field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy (FESEM-EDX), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and zeta potential (ζ potential). The crystallite size obtained from the results was 28.09 nm for Au/nanoceria. The energy-dispersive X-ray spectroscopy (EDX) analysis of Au/nanoceria revealed the compositional constituents of the product, which display the purity of the Au/nanoceria. The cell toxicity properties of the non-doped and Au-coated nanoceria were identified by a MTT analysis on a breast cancer cell line (MCF7). Additionally, human foreskin fibroblast cells (HFF) were used as a normal cell line. The cytotoxicity results indicated that the toxicological effect of Au/nanoceria on cancer cells was significant while having little toxic effect on normal cells. The toxicity effect of nanoceria clearly shows the dependence on dose and time, so, with increasing the dose of Au/nanoceria, the death of cancer cells also increases. [ABSTRACT FROM AUTHOR]

With the continuous utilization of green energy resource, energy storage devices are becoming one of the main issues in the field of energy. Supercapacitors have achieved great popularity owing to their several advantages in energy storage. For determining the efficiency of the supercapacitor, the electrode material is considered as the core element. Herein, mesoporous nanostructure of nickel ferrite (NiFe2O4) immobilized on boron, nitrogen and fluorine tri-doped CeO2 (NFTDNC) was prepared and scrutinized as supercapacitor material. The structural and compositional study of the synthesized material was done using characterizations, such as SEM, XRD, TEM, XPS and FTIR. The synthesized NFTDNC electrode demonstrates good electrochemical performance and shows 81.81% capacitance retention after 3000 GCD cycles. The achieved results verify the capability of the prepared NFTDNC electrode to be efficiently employed as cathode in the fabrication of high-performance supercapacitors. Moreover, the proposed material offers new opportunities in the domain of energy storage. [ABSTRACT FROM AUTHOR]

Nanomaterials are preferred for scientific studies due to their spectral properties and perfect surface appearance. This study aims to introduce a novel, environmentally friendly, photocatalytic method for degrading methylene blue (MB) in aqueous solutions. With this purpose in mind, the study synthesizes nanoceria particles and coats them with zahter (Thymbra spicata; zahter-coated nanoceria, ZCNC) following the main outlines of green chemistry as characterized by SEM and FTIR analyses. The study proposes this new nanoparticle (with the aid of H2 O2 and UV combinations) as an alternative to iron in Fenton-type reactions for enabling MB degradation. The maximum efficiency was observed through the ternary combination of zahter-coated nanoceria, UV light, and H2 O2 at 63% concentration. The degradation of the MB solution was achieved by installing a small amount of ZCNC (0.1g), after which the absorbance values were measured at 664 nm. According to the possible reaction kinetics discussed within the study, the reaction rate was calculated at 1.49 × 10-2 min -1, thus enabling a faster reaction for a better evaluation of the reaction mechanism compared to other degradation processes that have been previously investigated.

Mitochondrial dysfunction triggered by increased reactive oxygen species (ROS) generation is involved in the pathogenesis and development of cardiac hypertrophy. Nanoceria (cerium oxide nanoparticle) has powerful ROS-scavenging properties and is considered a potential therapeutic option for curbing ROS-related disorders. Here, we explored the signaling mechanism underlying the protective effects of nanoceria against angiotensin (Ang) II-stimulated pathological response in H9c2 cardiomyoblasts. Our data revealed that pretreatment of H9c2 cardiomyoblasts with nanoceria significantly prevented Ang II-stimulated generation of intracellular ROS, aberrant expression of pro-inflammatory cytokines, and hypertrophy markers. Nanoceria pretreatment increased the mRNA levels of genes regulating the cellular antioxidant defense system (SOD2, MnSOD, CAT) in Ang II-treated cells. Furthermore, nanoceria restored mitochondrial function by decreasing mitochondrial ROS, increasing mitochondrial membrane potential (MMP), and promoting the mRNA expression of genes associated with mitochondrial biogenesis (PGC-1α, TFAM, NRF1, and SIRT3) and mitochondrial fusion (MFN2, OPA1). Collectively, these findings demonstrate the protective effects of nanoceria against Ang II-mediated mitochondrial dysfunction and pathological hypertrophy in H9c2 cells. [ABSTRACT FROM AUTHOR]

Nanoparticle (NP) pharmacokinetics significantly differ from traditional small molecule principles. From this emerges the need to create new tools and concepts to harness their full potential and avoid unnecessary risks. Nanoparticle pharmacokinetics strongly depend on size, shape, surface functionalisation, and aggregation state, influencing their biodistribution, accumulation, transformations, and excretion profile, and hence their efficacy and safety. Today, while NP biodistribution and nanoceria biodistribution have been studied often at short times, their long-term accumulation and excretion have rarely been studied. In this work, 3 nm nanoceria at 5.7 mg/kg of body weight was intravenously administrated in a single dose to healthy mice. Biodistribution was measured in the liver, spleen, kidney, lung, brain, lymph nodes, ovary, bone marrow, urine, and faeces at different time points (1, 9, 30, and 100 days). Biodistribution and urinary and faecal excretion were also studied in rats placed in metabolic cages at shorter times. The similarity of results of different NPs in different models is shown as the heterogeneous nanoceria distribution in organs. After the expectable accumulation in the liver and spleen, the concentration of cerium decays exponentially, accounting for about a 50% excretion of cerium from the body in 100 days. Cerium ions, coming from NP dissolution, are most likely excreted via the urinary tract, and ceria nanoparticles accumulated in the liver are most likely excreted via the hepatobiliary route. In addition, nanoceria looks safe and does not damage the target organs. No weight loss or apathy was observed during the course of the experiments. [ABSTRACT FROM AUTHOR]

Bone defects in patients entail the microenvironment that needs to boost the functions of stem cells (e.g., proliferation, migration, and differentiation) while alleviating severe inflammation induced by high oxidative stress. Biomaterials can help to shift the microenvironment by regulating these multiple events. Here we report multifunctional composite hydrogels composed of photo-responsive Gelatin Methacryloyl (GelMA) and dendrimer (G3)-functionalized nanoceria (G3@nCe). Incorporation of G3@nCe into GelMA could enhance the mechanical properties of hydrogels and their enzymatic ability to clear reactive oxygen species (ROS). The G3@nCe/GelMA hydrogels supported the focal adhesion of mesenchymal stem cells (MSCs) and further increased their proliferation and migration ability (vs. pristine GelMA and nCe/GelMA). Moreover, the osteogenic differentiation of MSCs was significantly stimulated upon the G3@nCe/GelMA hydrogels. Importantly, the capacity of G3@nCe/GelMA hydrogels to scavenge extracellular ROS enabled MSCs to survive against H2O2-induced high oxidative stress. Transcriptome analysis by RNA sequencing identified the genes upregulated and the signalling pathways activated by G3@nCe/GelMA that are associated with cell growth, migration, osteogenesis, and ROS-metabolic process. When implanted subcutaneously, the hydrogels exhibited excellent tissue integration with a sign of material degradation while the inflammatory response was minimal. Furthermore, G3@nCe/GelMA hydrogels demonstrated effective bone regeneration capacity in a rat critical-sized bone defect model, possibly due to an orchestrated capacity of enhancing cell proliferation, motility and osteogenesis while alleviating oxidative stress.

The purpose of this study was to investigate the antimicrobial activity of citrate-stabilized sols of cerium oxide nanoparticles at different concentrations via different microbiological methods and to compare the effect with the peroxidase activity of nanoceria for the subsequent development of a regeneration-stimulating medical and/or veterinary wound-healing product providing new types of antimicrobial action. The object of this study was cerium oxide nanoparticles synthesized from aqueous solutions of cerium (III) nitrate hexahydrate and citric acid (the size of the nanoparticles was 3–5 nm, and their aggregates were 60–130 nm). Nanoceria oxide sols with a wide range of concentrations (10−1–10−6 M) as well as powder (the dry substance) were used. Both bacterial and fungal strains (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Proteus vulgaris, Candida albicans, Aspergillus brasielensis) were used for the microbiological studies. The antimicrobial activity of nanoceria was investigated across a wide range of concentrations using three methods sequentially; the antimicrobial activity was studied by examining diffusion into agar, the serial dilution method was used to detect the minimum inhibitory and bactericidal concentrations, and, finally, gas chromatography with mass-selective detection was performed to study the inhibition of E. coli’s growth. To study the redox activity of different concentrations of nanocerium, we studied the intensity of chemiluminescence in the oxidation reaction of luminol in the presence of hydrogen peroxide. As a result of this study’s use of the agar diffusion and serial dilution methods followed by sowing, no significant evidence of antimicrobial activity was found. At the same time, in the current study of antimicrobial activity against E. coli strains using gas chromatography with mass spectrometry, the ability of nanoceria to significantly inhibit the growth and reproduction of microorganisms after 24 h and, in particular, after 48 h of incubation at a wide range of concentrations, 10−2–10−5 M (48–95% reduction in the number of microbes with a significant dose-dependent effect) was determined as the optimum concentration. A reliable redox activity of nanoceria coated with citrate was established, increasing in proportion to the concentration, confirming the oxidative mechanism of the action of nanoceria. Thus, nanoceria have a dose-dependent bacteriostatic effect, which is most pronounced at concentrations of 10−2–10−3 M. Unlike the effects of classical antiseptics, the effect was manifested from 2 days and increased during the observation. To study the antimicrobial activity of nanomaterials, it is advisable not to use classical qualitative and semi-quantitative methods; rather, the employment of more accurate quantitative methods is advised, in particular, gas chromatography–mass spectrometry, during several days of incubation.

The increased commercial use and spread of nanoceria raises concerns about the risks associated with its effects on living organisms. Although Pseudomonas aeruginosa may be ubiquitous in nature, it is largely found in locations closely linked with human activity. P. aeruginosa san ai was used as a model organism for a deeper understanding of the interaction between biomolecules of the bacteria with this intriguing nanomaterial. A comprehensive proteomics approach along with analysis of altered respiration and production of targeted/specific secondary metabolites was conducted to study the response of P. aeruginosa san ai to nanoceria. Quantitative proteomics found that proteins associated with redox homeostasis, biosynthesis of amino acids, and lipid catabolism were upregulated. Proteins from outer cellular structures were downregulated, including transporters responsible for peptides, sugars, amino acids and polyamines, and the crucial TolB protein of the Tol-Pal system, required for the structural formation of the outer membrane layer. In accordance with the altered redox homeostasis proteins, an increased amount of pyocyanin, a key redox shuttle, and the upregulation of the siderophore, pyoverdine, responsible for iron homeostasis, were found. Production of extracellular molecules, e.g. pyocyanin, pyoverdine, exopolysaccharides, lipase, and alkaline protease, was significantly increased in P. aeruginosa san ai exposed to nanoceria. Overall, nanoceria at sublethal concentrations induces profound metabolic changes in P. aeruginosa san ai and provokes increased secretion of extracellular virulence factors, revealing the powerful influence this nanomaterial has on the vital functions of the microorganism. [ABSTRACT FROM AUTHOR]

The purpose of this study is to evaluate the literature for research trends on cerium oxide from 1990 to 2020 and identify gaps in knowledge in the emerging application(s) of CeONP. Bibliometric methods were used to identify themes in database searches from PubMed, Scopus and Web of Science Core Collection using SWIFT-Review, VOSviewer and SciMAT software programs. A systematic review was completed on published cerium oxide literature extracted from the Scopus database (n = 17,115), identifying themes relevant to its industrial, environmental and biomedical applications. A total of 172 publications were included in the systematic analysis and categorized into four time periods with research themes identified; "doping additives" (n = 5, 1990–1997), "catalysts" (n = 32, 1998–2005), "reactive oxygen species" (n = 66, 2006–2013) and "pathology" (n = 69, 2014–2020). China and the USA showed the highest number of citations and publications for cerium oxide research from 1990 to 2020. Longitudinal analysis showed CeONP has been extensively used for various applications due to its catalytic properties. In conclusion, this study showed the trend in research in CeONP over the past three decades with advancements in nanoparticle engineering like doping, and more recently surface modification or functionalization to further enhanced its antioxidant abilities. As a result of recent nanoparticle engineering developments, research into CeONP biological effects have highlighted its therapeutic potential for a range of human pathologies such as Alzheimer's disease. Whilst research over the past three decades show the versatility of cerium oxide in industrial and environmental applications, there are still research opportunities to investigate the potential beneficial effects of CeONP in its application(s) on human health. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DES) have demonstrated their ability to facilitate skin penetrability of rigid nanoparticles (NPs). Here, we reported a feasible and simple transdermal delivery strategy using mesoporous silica nanoparticles impregnated in DES hydrogels for topical management of rheumatoid arthritis (RA). To achieve this goal, nanoceria was immobilized within a silica nanoparticle matrix (MSN) and encapsulated with methotrexate (MTX). The functionalized nanoparticles were first engineered in an Arginine (Arg)–citric acid (CA) DES and then transferred to the carbomer hydrogel matrix. Due to the strong affinity of DES hydrogels to the skin, combined with solvent-driven "Drag" effects, the prepared DES–MSNs hydrogels produced dynamic mobility of MSNs through skin layers, resulting in high skin penetrability. After application to the skin, the hydrogel solvent drove the rigid NPs across the skin barrier in a nonintrusive manner, resulting in sustained penetration and accumulation of MSNs at subcutaneous inflammation sites. Subsequently, the MTX payload exerted a direct therapeutic effect, while nanoceria moderated the inflammatory microenvironment by initiating reactive oxygen species (ROS) scavenging and transformation of the macrophage phenotype. In this way, the synergistic action of the combination of immuno- and chemotherapy of the drug and its carrier on RA was achieved. Our work provides a novel strategy for multisite regulation and controlled management of RA in a noninvasive way. [Display omitted] [ABSTRACT FROM AUTHOR]

Aim: The functionalization and characterization of antibacterial nanoceria with folic acid (FA) and elucidation of their in vivo wound-healing application. Materials & methods: Functionalization of nanoceria were done with FA using a chemical method and their antibacterial activity, cellular biocompatibility and in vivo wound-healing application were evaluated. Results: The functionalization of nanoceria with FA was done with 10–20 nm size and -20.1 mV zeta potential. The nanoformulation showed a bacteriostatic effect along with biocompatibility to different cell lines; 0.1% w/v spray of FA-nanoceria demonstrated excellent wound-healing capacity within 14 days in a Wister rat model. Conclusion: The antioxidant and reactive oxygen species scavenging activity of the FA-nanoceria make it a promising therapeutic agent as a unique spray formulation in wound-healing applications. The emergence of chronic wounds is a main reason for mortality in patients with diabetes and other severe pathological complications. Advances in the use of nanotechnology have resulted in beneficial technology for tailoring of pharmacokinetic properties of different drug-delivery vehicles for different biomedical applications. In this study, folic acid (FA) functionalized nanoceria (FA-nanoceria) were formulated and their potential efficacy in the wound-healing process was explored. The nanoformulation showed a remarkable bacteriostatic effect on both Gram-negative and Gram-positive bacteria. In vitro cell line studies showed satisfactory biocompatibility in three different types of cell lines. In addition, a 0.1% w/v spray of FA-nanoceria was applied to full-thickness wounds in an in vivo mice model where it demonstrated excellent wound-healing capacity within 14 days. The combined antioxidant and reactive oxygen species scavenging activity of both the FA and nanoceria makes FA-nanoceria a promising therapeutic agent as a unique spray formulation in wound-healing applications. [ABSTRACT FROM AUTHOR]

Nanomaterials are preferred for scientific studies due to their spectral properties and perfect surface appearance. This study aims to introduce a novel, environmentally friendly, photocatalytic method for degrading methylene blue (MB) in aqueous solutions. With this purpose in mind, the study synthesizes nanoceria particles and coats them with zahter (Thymbra spicata; zahter-coated nanoceria, ZCNC) following the main outlines of green chemistry as characterized by SEM and FTIR analyses. The study proposes this new nanoparticle (with the aid of H2O2 and UV combinations) as an alternative to iron in Fenton-type reactions for enabling MB degradation. The maximum efficiency was observed through the ternary combination of zahter-coated nanoceria, UV light, and H2O2 at 63% concentration. The degradation of the MB solution was achieved by installing a small amount of ZCNC (0.1g), after which the absorbance values were measured at 664 nm. According to the possible reaction kinetics discussed within the study, the reaction rate was calculated at 1.49 × 10-2 min -1, thus enabling a faster reaction for a better evaluation of the reaction mechanism compared to other degradation processes that have been previously investigated. [ABSTRACT FROM AUTHOR]

The number of bone damage/fractures has been increasing significantly over the world due to traumatic and accidental injuries. The process of bone regeneration is slowed by oxidative stress at the site of the bone defects. An increase in reactive oxygen species (ROS) is the major cause of oxidative stress. Polymeric scaffolds loaded with free radical scavenging material could be a promising new way to speed up bone healing. The redox-modulating property of cerium oxide (nanoceria) is well-known. In this study, nanoceria was integrated into cellulose-gelatin (CG) and freeze-dried to produce CG-NCs scaffolds. The impact of different concentrations of nanoceria on the physicochemical and biological aspects of scaffolds has also been investigated. FESEM revealed the presence of interconnecting pores in the scaffolds. Furthermore , adding nanoceria to the scaffolds improved mechanical, bio-mineralization properties, and decreased swelling and in-vitro weight loss. In vitro studies confirmed that CG-NCs scaffolds supported cell proliferation and differentiation better than bare (CG) scaffold. The findings of the DPPH assay show that CG-NCs can reduce free radicals. Finally, the antimicrobial evaluations imply that CG-NCs scaffolds successfully inhibited S. aureus and e.coli growth. Thus, the CG-NCs scaffold could offer a lot of potential in bone tissue engineering. [ABSTRACT FROM AUTHOR]

Exposure to ultraviolet radiation induces photodamage towards cellular macromolecules that can progress to photoaging and photocarcinogenesis. The topical administration of compounds that maintain the redox balance in cells presents an alternative approach to combat skin oxidative damage. Cerium oxide nanoparticles (CNPs) can act as antioxidants due to their enzyme-like activity. In addition, a recent study from our group has demonstrated the photoprotective potential of tannic acid (TA). Therefore, this work aimed to synthesize CNPs associated with TA (CNP-TA) and investigate its photoprotective activity in L929 fibroblasts exposed to UVB radiation. CNP conjugation with TA was confirmed by UV–Vis spectra and X-ray photoelectron spectroscopy. Bare CNPs and CNP-TA exhibited particle sizes of ~5 and ~10 nm, superoxide dismutase activity of 3724 and 2021 unit/mg, and a zeta potential of 23 and −19 mV, respectively. CNP-TA showed lower cytotoxicity than free TA and the capacity to reduce the oxidative stress caused by UVB; supported by the scavenging of reactive oxygen species, the prevention of endogenous antioxidant system depletion, and the reduction in oxidative damage in lipids and DNA. Additionally, CNP-TA improved cell proliferation and decreased TGF-β, metalloproteinase-1, and cyclooxygenase-2. Based on these results, CNP-TA shows therapeutic potential for protection against photodamage, decreasing molecular markers of photoaging and UVB-induced inflammation. [ABSTRACT FROM AUTHOR]

Nanoscale cerium–bismuth oxides/oxynitrates were prepared by a scalable low-temperature method at ambient pressure using water as the sole solvent. Solid solutions were formed up to a 1:1 Ce/Bi molar ratio, while at higher doping levels, bismuth oxynitrate photocatalysts with a pronounced layered structure were formed. Bismuth caused significant changes in the structure and surface properties of nanoceria, such as the formation of defects, oxygen-containing surface groups, and Lewis and Brønsted acid sites. The prepared bifunctional adsorbents/photocatalysts were efficient in the removal of toxic organophosphate (methyl paraoxon) from water by reactive adsorption followed by photocatalytic decomposition of the parent compound and its degradation product (p-nitrophenol). Bi-doped ceria also effectively adsorbed and photodegraded the endocrine disruptors bisphenols A and S and outperformed pure ceria and the P25 photocatalyst in terms of efficiency, durability, and long-term stability. The very low toxicity of Bi-nanoceria to mammalian cells, aquatic organisms, and bacteria has been demonstrated by comprehensive in vivo/in vitro testing, which, in addition to its simple "green" synthesis, high activity, and durability, makes Bi-doped ceria promising for safe use in abatement of toxic chemicals. [ABSTRACT FROM AUTHOR]

Tuning morphology and doping additional rare earth (RE) cations are potential techniques to promote the photocatalytic performance of ceria (CeO2), evaluating the collaborative effects of morphology and RE dopants is significant for producing high active ceria-based catalysts. So in this work, cubic, polyhedral and rod-like nanoceria doped with 10 mol % La (lanthanum), Y (yttrium), or Sm (samarium) were synthesized by a facile template-free hydrothermal method. Phases, morphologies, oxygen vacancies (OVs) concentration, energy band structure, photo-carriers separation/recombination, and photodegradation ratio toward methylene blue (MB) dye of as prepared ceria were studied. Results show that doped CeO2 maintains a similar morphology structure with un-doped sample and the band gap narrows slightly. Y-doped nanoceria, with an improved separation and a reduced recombination of photo-excited electrons (e−) and holes (h+), owns a higher MB photodegradation ratio than that of samples doping with La or Sm, which is measured as 79.04, 84.43, and 85.59% for Y-doped cubic, polyhedral, and rod-like CeO2. The collaborative influence of morphology tuning and RE (La, Y, and Sm) doping on photocatalytic performance of nanoceria includes the effects of doped elements and the formation of OVs. The elevation of OVs concentration as well as the separation efficiency of photo-generated e−/h+ are suggested to further enhance the photocatalytic performance of ceria. [ABSTRACT FROM AUTHOR]

This study is one of the first attempts to assess CeO2 nanoparticles as a nanoplatform for radiopharmaceuticals with radionuclides. The process of functionalization using a bifunctional azacrown ligand is described, and the resulting conjugates are characterized by IR and Raman spectroscopy. Their complexes with 207Bi show a high stability in medically relevant media, thus encouraging the further study of these conjugates in vivo as potential combined radiopharmaceuticals. [ABSTRACT FROM AUTHOR]

Abstract Background There is an increasing concern about the neurotoxicity of engineered nanomaterials (NMs). To investigate the effects of subchronic oral exposures to SiO2 and CeO2 NMs on Alzheimer’s disease (AD)-like pathology, 5xFAD transgenic mice and their C57BL/6J littermates were fed ad libitum for 3 or 14 weeks with control food pellets, or pellets dosed with these respective NMs at 0.1% or 1% (w/w). Behaviour effects were evaluated by X-maze, string suspension, balance beam and open field tests. Brains were analysed for plaque load, beta-amyloid peptide levels, markers of oxidative stress and neuroinflammation. Results No marked behavioural impairments were observed in the mice exposed to SiO2 or CeO2 and neither treatment resulted in accelerated plaque formation, increased oxidative stress or inflammation. In contrast, the 5xFAD mice exposed to 1% CeO2 for 14 weeks showed significantly lower hippocampal Aβ plaque load and improved locomotor activity compared to the corresponding controls. Conclusions The findings from the present study suggest that long-term oral exposure to SiO2 or CeO2 NMs has no neurotoxic and AD-promoting effects. The reduced plaque burden observed in the mice following dietary CeO2 exposure warrants further investigation to establish the underlying mechanism, given the easy applicability of this administration method.

Nanomaterials as an emerging tool are being used to improve plant's net photosynthetic rate (A N) when suffering salt stress, but the underlying mechanisms remain unclear. To clarify this, a hydroponic experiment was conducted to study the effects of polyacrylic acid coated nanoceria (PNC) on the A N of salt-stressed cotton and related intrinsic mechanisms. Results showed that the PNC-induced A N enhancement of salt-stressed leaves was strongly facilitated by the mesophyll conductance to CO 2 (g m). Further analysis showed that the PNC-induced improvement of g m was related to the increased chloroplast surface area exposed to intercellular airspaces, which was attribute to the increased mesophyll surface area exposed to intercellular airspaces and chloroplast number due to the increased K+ content and decreased reactive oxygen species level in salt-stressed leaves. Interestingly, our results also showed that PNC-induced variations in cell wall composition of salt-stressed cotton leaves strongly influenced g m , especially, hemicellulose and pectin. Moreover, the proportion of pectin in cell wall composition played a more important role in determining g m. Our study demonstrated for the first time that nanoceria, through alterations to anatomical traits and cell wall composition, drove g m enhancement, which ultimately increased A N of salt-stressed leaves. • Foliar application of CeO 2 NPs enhances growth and photosynthesis of cotton under salt stress. • CeO 2 NPs-induced enhancement in g m of salt-stressed cotton leaves is a key determinant for promoting photosynthesis. • CeO 2 NPs-induced variations in leaf anatomy partly explain the enhancement of g m to salt-stressed cotton leaves. • CeO 2 NPs-induced variations in cell wall composition also strongly influence the g m of salt-stressed cotton leaves. [ABSTRACT FROM AUTHOR]

[Display omitted] • The carbon/cerium oxide composites were prepared with the assistance of the glucose-based surfactant and impregnated to Fabrics. • The resultant CeO 2 –C composites exhibited excellent antibacterial activity. • The nanocomposites demonstrate efficient sunlight-driven photocatalytic activity. • The nanocomposites results in a synergistic effect, enhancing both antibacterial and photocatalytic performances. • The developed textiles hold promise for various healthcare applications. This work inspects the antibacterial activity and sunlight-driven photocatalytic activity effect of nanocomposites of CeO 2 and carbon as a surface coating onto the fabric with self-cleaning properties. The nanocomposites of CeO 2 and carbon were confirmed by XRD, FTIR, Laser Raman and TEM, revealing the amorphous nature of carbon and the crystallographic structure of CeO 2 nanoparticles. TEM depicted a sheet-like structure of carbon and orbicular morphology of CeO 2. The nanocomposite was impregnated onto fabrics using an immersion and ultrasonication method. The fabrics impregnated with nanocomposites exposed a clear zone of inhibition of E. Coli and S.aureus bacterial strains, indicating potent bactericidal properties. The nanocomposite-impregnated fabrics show efficient and strong photocatalytic activity against P-Rosaniline Hydrochloride (PRH) dye, which was investigated at different concentrations of dye, repeatability, and reusability with time. The notable photocatalytic activity of the fabrics underscores their potential for use in anti-infection applications. [ABSTRACT FROM AUTHOR]

Nonalcoholic fatty liver disease (NAFLD) describes a spectrum of liver abnormalities, from benign steatosis to nonalcoholic steatohepatitis (NASH). Because of their antioxidant capabilities, CeNPs have sparked a lot of interest in biological applications. This review evaluated the effectiveness of CeNPs in NAFLD evolution through in vivo and in vitro studies. Databases such as MEDLINE, EMBASE, Scopus, and Web of Science were looked for studies published between 2012 and June 2023. Quality was evaluated using PRISMA guidelines. We looked at a total of nine primary studies in English carried out using healthy participants or HepG2 or LX2 cells. Quantitative data such as blood chemical markers, lipid peroxidation, and oxidative status were obtained from the studies. Our findings indicate that NPs are a possible option to make medications safer and more effective. In fact, CeNPs have been demonstrated to decrease total saturated fatty acids and foam cell production (steatosis), reactive oxygen species production and TNF-α (necrosis), and vacuolization in hepatic tissue when used to treat NAFLD. Thus, CeNP treatment may be considered promising for liver illnesses. However, limitations such as the variation in durations between studies and the utilization of diverse models to elucidate the etiology of NAFLD must be considered. Future studies must include standardized NAFLD models.

In the ongoing search for practical uses of rare-earth metal nanoparticles, cerium dioxide nanoparticles (nanoceria) have received special attention. The purpose of this research was to study the biomedical effects of nanocrystalline forms of cerium oxide obtained by different synthesis schemes and to evaluate the effect of different concentrations of nanoceria (from 10−2 to 10−6 M) on cells involved in the regeneration of skin cell structures such as fibroblasts, mesenchymal stem cells, and keratinocytes. Two different methods of nanoceria preparation were investigated: (1) CeO-NPs-1 by precipitation from aqueous solutions of cerium (III) nitrate hexahydrate and citric acid and (2) CeO-NPs-2 by hydrolysis of ammonium hexanitratocerate (IV) under conditions of thermal autoclaving. According to the X-ray diffraction, transmission electron microscopy, and dynamic light scattering data, CeO2-1 consists of individual particles of cerium dioxide (3–5 nm) and their aggregates with diameters of 60–130 nm. CeO2-2 comprises small aggregates of 8–20 nm in diameter, which consist of particles of 2–3 nm in size. Cell cultures of human fibroblasts, human mesenchymal stem cells, and human keratinocytes were cocultured with different concentrations of nanoceria sols (10−2, 10−3, 10−4, 10−5, and 10−6 mol/L). The metabolic activity of all cell types was investigated by MTT test after 48 and 72 h, whereas proliferative activity and cytotoxicity were determined by quantitative cell culture counting and live/dead test. A dependence of biological effects on the method of nanoceria preparation and concentration was revealed. Data were obtained with respect to the optimal concentration of sol to achieve the highest metabolic effect in the used cell cultures. Hypotheses about the mechanisms of the obtained effects and the structure of a fundamentally new medical device for accelerated healing of skin wounds were formulated. The method of nanoceria synthesis and concentration fundamentally and significantly change the biological activity of cell cultures of different types—from suppression to pronounced stimulation. The best biological activity of cell cultures was determined through cocultivation with sols of citrate nanoceria (CeO-NPs-1) at a concentration of 10−3–10−4 M.