Search Results (15)

Excessive levels of heavy metal pollutants in the environment pose significant threats to human health and ecosystem stability. Consequently, the accurate and rapid detection of heavy metal ions is critically important. A AgNPs@CeO₂/Nafion composite was prepared by dispersing nano-ceria (CeO₂) in a Nafion solution and incorporating silver nanoparticles (AgNPs). The morphology, microstructure, and electrochemical properties of the modified electrode materials were systematically characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and cyclic voltammetry (CV). By leveraging the oxygen vacancies and high electron transfer efficiency of CeO₂, the strong adsorption capacity of Nafion, and the superior conductivity of AgNPs, an AgNPs@CeO₂/Nafion/GCE electrochemical sensor was developed. Under optimized conditions, trace Pb²⁺ in water was detected using square wave anodic stripping voltammetry (SWASV). The sensor demonstrated a linear response for Pb²⁺ within the concentration range of 1–100 μg·L⁻¹, with a detection limit of 0.17 μg·L⁻¹ (S/N = 3). When applied to real water samples, the method achieved recovery rates between 93.7% and 110.3%, validating its reliability and practical applicability. Full article

In this work, CeBTC (a cerium(III) 1,3,5-benzene-tricarboxylate), was used as a precursor for obtaining CeO₂ nanoparticles (nanoceria) with better sensor performances than CeO₂ nanoparticles synthesized by the solvothermal method. Metal–organic framework-derived nanoceria (MOFdNC) were functionalized with spheric gold nanoparticles (AuNPs) to further improve non-enzymatic electrode material for highly sensitive detection of prominent biocompound uric acid (UA) at this modified carbon paste electrode (MOFdNC/AuNPs&CPE). X-ray powder diffraction (XRPD) and transmission electron microscopy (TEM) analysis were used for morphological structure characterization of the obtained nanostructures. Cyclic voltammetry and electrochemical impedance spectroscopy, both in an [Fe(CN)₆]^3−/4− redox system and uric acid standard solutions, were used for the characterization of material electrocatalytic performances, the selection of optimal electrode modifier, and the estimation of nature and kinetic parameters of the electrode process. Square-wave voltammetry (SWV) was chosen, and the optimal parameters of technique and experimental conditions were established for determining uric acid over MOFdNC/AuNPs&CPE. Together with the development of the sensor, the detection procedure was optimized with the following analytical parameters: linear operating ranges of 0.05 to 1 µM and 1 to 50 µM and a detection limit of 0.011 µM, with outstanding repeatability, reproducibility, and stability of the sensor surface. Anti-interference experiments yielded a stable and nearly unchanged current response with negligible or no change in peak potential. After minor sample pretreatment, the proposed electrode was successfully applied for the quantification of UA in milk. Full article

Background/Objectives: The issue of effective wound healing remains highly relevant. The objective of the study is to develop an optimal method for the synthesis of nanosized cerium oxide powder obtained via the thermal decomposition of cerium carbonate precipitated from aqueous nitrate solution for the technical creation of new drugs in production conditions; the select modification of synthesis under different conditions based on the evaluation of the physicochemical characteristics of the obtained material and its biological activity, and an evaluation of the broad-spectrum effect on cells involved in the regeneration of skin structure as well as antimicrobial properties. Methods: Several modes of the industrial synthesis of cerium dioxide nanoparticles (NPs) were carried out. The synthesis stages and the chemical and physical parameters of the obtained NPs were described using transmission electron microscopy (TEM), X-ray diffraction, Raman spectroscopy, and mass spectrometry. The cell cultures of human fibroblasts and keratinocytes were cultured with different concentrations of different nanoceria variations, and the cytotoxicity and the metabolic and proliferative activity were investigated. An MTT test and cell counting were performed. The antimicrobial activity of CeO₂ variations at a concentration of 0.1–0.0001 M against Pseudomonas aeruginosa was studied. Results: The purity of the synthesized nanoceria powders in all the batches was >99.99%. According to TEM data, the size of the NPs varied from 1 nm to 70 nm under different conditions and methodologies. The most optimal technology for the synthesis of the nanoceria with the maximum biological effect was selected. A method for obtaining the most bioactive NPs of optimal size (up to 10 nm) was proposed. The repeatability of the results of the proposed method of nanoceria synthesis in terms of particle size was confirmed. It was proven that the more structural defects on the surface of the CeO₂ crystal lattice, the higher the efficiency of the NPs due to oxygen vacancies. The strain provided the best redox activity and antioxidant properties of the nanoceria, which was demonstrated by better regenerative potential on various cell lines. The beneficial effect of synthesized nanoceria on the proliferative and metabolic activity of the cell lines involved in skin regeneration (human fibroblasts, human keratinocytes) was demonstrated. The antimicrobial effect of synthesized nanoceria on the culture of the most-resistant-to-modern-antibiotics microorganism Pseudomonas aeruginosa was confirmed. The optimal concentrations of the nanoceria to achieve the maximum biological effect were determined (10⁻³ M). Conclusions: It was possible to develop a method for the industrial synthesis of nanoceria, which can be used to produce drugs and medical devices containing CeO₂ NPs. Full article

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. Full article

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. Full article

In this work we studied nanoceria (CeO₂NPs) and nanoceria modified by 5-fluorouracil (5FU) as potential APIs. Nanoceria were synthesized by precipitation in a matrix of hydroxyethyl cellulose or hydroxypropylmethyl cellulose, using cerium (III) nitrate and meglumine. Nanoceria properties were estimated by UV, FTIR and X-ray photoelectron spectra; scanning electron and atomic force microscopy; powder X-ray diffraction patterns and energy dispersive X-ray microanalysis. The cytotoxicity of nanoceria and polymer-protected nanoparticles was evaluated using the established cell line NCTC clone 929 (C3H/An mouse, subcutaneous connective tissue, clone of L. line). The morphology and metabolic activity of nanoparticles at 10 μg∙mL⁻¹ of cells was not significant. In addition, the cytotoxic effects of nanoceria were assessed on two human colorectal cancer cell lines (HT29 and HCT116), murine melanoma B16 cells and normal human skin fibroblasts. An inhibitory effect was shown for HCT116 human colorectal cancer cells. The IC₅₀ values for pure CeO₂NPs and CeO₂NPs-5FU were 219.0 ± 45.6 μg∙mL⁻¹ and 89.2 ± 14.0 μg∙mL⁻¹, respectively. On the other hand, the IC₅₀ of 5FU in the combination of CeO₂NPs-5FU was 2-fold higher than that of pure 5FU, amounting to 5.0 nmol∙mL⁻¹. New compositions of nanoceria modified by 5-fluorouracil in a polymer matrix were designed as a dermal polymer film and gel. The permeability of the components was studied using a Franz cell. Full article

Cerium dioxide nanoparticles (CeO₂NP) show antioxidant enzyme-like properties and reactive oxygen species (ROS) scavenging activity, making them a promising material for potential therapeutic applications in neurodegenerative diseases. The objective of this work was to assess the biological behavior of CeO₂NP in human SH-SY5Y neuronal and A172 glial cells by means of the MTT assay and the γH2AX assay. Despite the significant dose- and time-dependent NP internalization by both cell lines, nanoceria generally presented scarce cytotoxicity or genotoxicity, essentially restricted to the highest NP doses and longest exposure times. In conclusion, a high biocompatibility of CeO₂NP was observed under the conditions tested. Full article

A soft synthesis of nanoceria with non-stoichiometric composition (33% Ce³⁺/67% Ce⁴⁺) named CeO₂ NPs in bacterial cellulose (BC) matrix in the form of aerogel and hydrogel with controlled CeO₂ NPs content was proposed. The advantage of CeO₂ NPs synthesis in BC is the use of systemic antacid API–trisamine as a precursor, which did not destruct cellulose at room temperature and enabled a reduction in the duration of synthesis and the number of washes. Moreover, this method resulted in the subsequent uniform distribution of CeO₂ NPs in the BC matrix due to cerium (III) nitrate sorption in the BC matrix. CeO₂ NPs (0.1–50.0%) in the BC matrix had a fluorite structure with a size of 3–5 nm; the specific surface area of the composites was 233.728 m²/g. CeO₂ NPs in the BC-CeO₂ NPs composite demonstrated SOD-like activity in the processes of oxidation and reduction of cytochrome c (cyt c³⁺/cyt c²⁺), as well as epinephrine to inhibit its auto-oxidation in aqueous solutions by 33–63% relative to the control. In vitro experiments on rat blood showed a decrease in the MDA level and an increase in the activity of antioxidant defense enzymes–SOD by 24% and G6PDH by 2.0–2.5 times. Therefore, BC-CeO₂ NPs can be proposed for wound healing as antioxidant material. Full article

Oxidative stress is known to be associated with a number of degenerative diseases. A better knowledge of the interplay between oxidative stress and amyloidogenesis is crucial for the understanding of both, aging and age-related neurodegenerative diseases. Cerium dioxide nanoparticles (CeO₂ NPs, nanoceria) due to their remarkable properties are perspective nanomaterials in the study of the processes accompanying oxidative-stress-related diseases, including amyloid-related pathologies. In the present work, we analyze the effects of CeO₂ NPs of different sizes and Ce⁴⁺/Ce³⁺ ratios on the fibrillogenesis of insulin, SOD-like enzymatic activity, oxidative stress, biocompatibility, and cell metabolic activity. CeO₂ NPs (marked as Ce1–Ce5) with controlled physical–chemical parameters, such as different sizes and various Ce⁴⁺/Ce³⁺ ratios, are synthesized by precipitation in water–alcohol solutions. All synthesized NPs are monodispersed and exhibit good stability in aqueous suspensions. ThT and ANS fluorescence assays and AFM are applied to monitor the insulin amyloid aggregation and antiamyloid aggregation activity of CeO₂ NPs. The analyzed Ce1–Ce5 nanoparticles strongly inhibit the formation of insulin amyloid aggregates in vitro. The bioactivity is analyzed using SOD and MTT assays, Western blot, fluorescence microscopy, and flow cytometry. The antioxidative effects and bioactivity of nanoparticles are size- or valence-dependent. CeO₂ NPs show great potential benefits for studying the interplay between oxidative stress and amyloid-related diseases, and can be used for verification of the role of oxidative stress in amyloid-related diseases. Full article

The current study demonstrated the capability of using maize silk as a green, simple, clean, safe, and cost-effective platform for the biosynthesis of cerium oxide (CeO₂NPs). Several spectroscopic and microscopic analyses were employed to characterize the resulted biogenic nanoceria. When the concentration of the CeO₂NPs was elevated from 25 to 100 ug mL⁻¹, the CeO₂NPs exhibited strong scavenging potential ranging from 60.21 to 75.11% and 56 to 77% for 1,1-diphenyl-2- picrylhydrazyl (DPPH•) and 2-2′-azino-bis(3-ethyl benzothiazoline-6-sulphonic acid) (ABTS) tests, respectively. The quantitative determination of ferulic, sinapic, and p-coumaric acids was carried out using an eco-friendly, cost-effective, and optimized ultrasensitive nanoceria enhanced sequential injection-chemiluminescence (SIA-CL) system. The highest amount was presented by the ferulic acid (1636 ± 2.61 ug/g_dw), followed by p-coumaric acid (206 ± 1.12 ug/g_dw) and sinapic acid (123 ± 2.15 ug/g_dw). The intrinsic capabilities of the biogenic CeO₂NPs in enhancing the developed system reveal its potential role in detecting phenolic compounds with great sensitivity. Full article

The human placenta is a transient organ essential for pregnancy maintenance, fetal development and growth. It has several functions, including that of a selective barrier against pathogens and xenobiotics from maternal blood. However, some pollutants can accumulate in the placenta or pass through with possible repercussions on pregnancy outcomes. Cerium dioxide nanoparticles (CeO₂ NPs), also termed nanoceria, are an emerging pollutant whose impact on pregnancy is starting to be defined. CeO₂ NPs are already used in different fields for industrial and commercial applications and have even been proposed for some biomedical applications. Since 2010, nanoceria have been subject to priority monitoring by the Organization for Economic Co-operation and Development in order to assess their toxicity. This review aims to summarize the current methods and models used for toxicology studies on the placental barrier, from the basic ones to the very latest, as well as to overview the most recent knowledge of the impact of CeO₂ NPs on human health, and more specifically during the sensitive window of pregnancy. Further research is needed to highlight the relationship between environmental exposure to CeO₂ and placental dysfunction with its implications for pregnancy outcome. Full article

Submicron biomaterials have recently been found with a wide range of applications for biomedical purposes, mostly due to a considerable decrement in size and an increment in surface area. There have been several attempts to use innovative nanoscale biomaterials for tissue repair and tissue regeneration. One of the most significant metal oxide nanoparticles (NPs), with numerous potential uses in future medicine, is engineered cerium oxide (CeO₂) nanoparticles (CeONPs), also known as nanoceria. Although many advancements have been reported so far, nanotoxicological studies suggest that the nanomaterial’s characteristics lie behind its potential toxicity. Particularly, physicochemical properties can explain the positive and negative interactions between CeONPs and biosystems at molecular levels. This review represents recent advances of CeONPs in biomedical engineering, with a special focus on tissue engineering and regenerative medicine. In addition, a summary report of the toxicity evidence on CeONPs with a view toward their biomedical applications and physicochemical properties is presented. Considering the critical role of nanoengineering in the manipulation and optimization of CeONPs, it is expected that this class of nanoengineered biomaterials plays a promising role in the future of tissue engineering and regenerative medicine. Full article

Retinal pigment epithelium (RPE) dysfunction and degeneration underlie the development of age-related macular degeneration (AMD), which is the leading cause of blindness worldwide. In this study, we investigated whether cerium oxide nanoparticles (CeO₂-NPs or nanoceria), which are anti-oxidant agents with auto-regenerative properties, are able to preserve the RPE. On ARPE-19 cells, we found that CeO₂-NPs promoted cell viability against H₂O₂–induced cellular damage. For the in vivo studies, we used a rat model of acute light damage (LD), which mimics many features of AMD. CeO₂-NPs intravitreally injected three days before LD prevented RPE cell death and degeneration and nanoceria labelled with fluorescein were found localized in the cytoplasm of RPE cells. CeO₂-NPs inhibited epithelial-mesenchymal transition of RPE cells and modulated autophagy by the down-regulation of LC3B-II and p62. Moreover, the treatment inhibited nuclear localization of LC3B. Taken together, our study demonstrates that CeO₂-NPs represent an eligible candidate to counteract RPE degeneration and, therefore, a powerful therapy for AMD. Full article

Cerium oxide nanoparticles (CeO₂-NPs) have great applications in different industries, including nanomedicine. However, some studies report CeO₂-NPs-related toxicity issues that limit their usage and efficiency. In this study, the sol–gel method was applied to the synthesis of CeO₂-NPs using poly(allylamine) (PAA) as a capping and/or stabilizing agent. The different molecular weights of PAA (15,000, 17,000, and 65,000 g/mol) were used to investigate the physico-chemical and biological properties of the NPs. In order to understand their performance as an anticancer agent, three cell lines (MCF7, HeLa, and erythrocyte) were analyzed by MTT assay and RBC hemolysis assay. The results showed that the CeO₂-NPs had anticancer effects on the viability of MCF7 cells with half-maximal inhibitory concentration (IC50) values of 17.44 ± 7.32, 6.17 ± 1.68, and 0.12 ± 0.03 μg/mL for PAA15000, PAA17000, PAA65000, respectively. As for HeLa cells, IC50 values reduced considerably to 8.09 ± 1.55, 2.11 ± 0.33, and 0.20 ± 0.01 μg/mL, in order. A decrease in the viability of cancer cells was associated with the 50% hemolytic concentration (HC50) of 0.022 ± 0.001 mg/mL for PAA15000, 3.74 ± 0.58 mg/mL for PAA17000, and 7.35 ± 1.32 mg/mL for PAA65000. Ultraviolet-Visible (UV-vis) spectroscopy indicated that an increase in the PAA molecular weight led to a blue shift in the bandgap and high amounts of Ce³⁺ on the surface of the nanoceria. Thus, PAA65000 could be considered as a biocompatible nanoengineered biomaterial for potential applications in cancer nanomedicine. Full article

Previously, catalytic cerium oxide nanoparticles (CNPs, nanoceria, CeO2-x NPs) have been widely utilized for chemical mechanical planarization in the semiconductor industry and for reducing harmful emissions and improving fuel combustion efficiency in the automobile industry. Researchers are now harnessing the catalytic repertoire of CNPs to develop potential new treatment modalities for both oxidative- and nitrosative-stress induced disorders and diseases. In order to reach the point where our experimental understanding of the antioxidant activity of CNPs can be translated into useful therapeutics in the clinic, it is necessary to evaluate the most current evidence that supports CNP antioxidant activity in biological systems. Accordingly, the aims of this review are three-fold: (1) To describe the putative reaction mechanisms and physicochemical surface properties that enable CNPs to both scavenge reactive oxygen species (ROS) and to act as antioxidant enzyme-like mimetics in solution; (2) To provide an overview, with commentary, regarding the most robust design and synthesis pathways for preparing CNPs with catalytic antioxidant activity; (3) To provide the reader with the most up-to-date in vitro and in vivo experimental evidence supporting the ROS-scavenging potential of CNPs in biology and medicine. Full article