Cytotoxicity and Genotoxicity of Ceria Nanoparticles on Different Cell Lines in Vitro

Owing to their radical scavenging and UV-filtering properties, ceria nanoparticles (CeO₂-NPs) are currently used for various applications, including as catalysts in diesel particulate filters. Because of their ability to filter UV light, CeO₂-NPs have garnered significant interest in the medical field and, consequently, are poised for use in various applications. The aim of this work was to investigate the effects of short-term (24 h) and long-term (10 days) CeO₂-NP exposure to A549, CaCo2 and HepG2 cell lines. Cytotoxicity assays tested CeO₂-NPs over a concentration range of 0.5 μg/mL to 5000 μg/mL, whereas genotoxicity assays tested CeO₂-NPs over a concentration range of 0.5 μg/mL to 5000 μg/mL. In vitro assays showed almost no short-term exposure toxicity on any of the tested cell lines. Conversely, long-term CeO₂-NP exposure proved toxic for all tested cell lines. NP genotoxicity was detectable even at 24-h exposure. HepG2 was the most sensitive cell line overall; however, the A549 line was most sensitive to the lowest concentration tested. Moreover, the results confirmed the ceria nanoparticles’ capacity to protect cells when they are exposed to well-known oxidants such as H₂O₂. A Comet assay was performed in the presence of both H₂O₂ and CeO₂-NPs. When hydrogen peroxide was maintained at 25 μM, NPs at 0.5 μg/mL, 50 μg/mL, and 500 μg/mL protected the cells from oxidative damage. Thus, the NPs prevented H₂O₂-induced genotoxic damage.     

Attenuation of Combined Nickel(II) Oxide and Manganese(II,III) Oxide Nanoparticles’ Adverse Effects with a Complex of Bioprotectors

Stable suspensions of NiO and Mn₃O₄ nanoparticles (NPs) with a mean (±s.d.) diameter of 16.7 ± 8.2 and 18.4 ± 5.4 nm, respectively, purposefully prepared by laser ablation of 99.99% pure nickel or manganese in de-ionized water, were repeatedly injected intraperitoneally (IP) to rats at a dose of 2.5 mg/kg 3 times a week up to 18 injections, either alone or in combination. A group of rats was injected with this combination with the background oral administration of a “bio-protective complex” (BPC) comprising pectin, vitamins A, C, E, glutamate, glycine, N-acetylcysteine, selenium, iodide and omega-3 PUFA, this composition having been chosen based on mechanistic considerations and previous experience. After the termination of injections, many functional and biochemical indices and histopathological features (with morphometric assessment) of the liver, spleen, kidneys and brain were evaluated for signs of toxicity. The Ni and Mn content of these organs was measured with the help of the atomic emission and electron paramagnetic resonance spectroscopies. We obtained blood leukocytes for performing the RAPD (Random Amplified Polymorphic DNA) test. Although both metallic NPs proved adversely bio-active in many respects considered in this study, Mn₃O₄-NPs were somewhat more noxious than NiO-NPs as concerns most of the non-specific toxicity manifestations and they induced more marked damage to neurons in the striatum and the hippocampus, which may be considered an experimental correlate of the manganese-induced Parkinsonism. The comparative solubility of the Mn₃O₄-NPs and NiO-NPs in a biological medium is discussed as one of the factors underlying the difference in their toxicokinetics and toxicities. The BPC has attenuated both the organ-systemic toxicity and the genotoxicity of Mn₃O₄-NPs in combination with NiO-NPs.     

Impact of physicochemical properties of cerium oxide nanoparticles on their toxicity effects

The advancing production and application of cerium oxide nanoparticles (CeO₂-NPs) in recent years have raised scientists concern about their toxicity. Numerous investigations have been performed to study the toxicity of CeO₂-NPs although their results are sometimes contradictory. In this review, we display the most important factors that are effective in CeO₂-NPs toxicity. The studies are classified based on the target that is selected for toxicity assessment (cytotoxicity, respiratory toxicity, hepatotoxicity, neurotoxicity, dermal toxicity, phytotoxicity, and environmental toxicity). Various representative examples are presented in each class. It seems to be difficult to achieve a comprehensive view and a deterministic conclusion since several parameters are involved in interpreting the results. In order to reach repeatable and comparable results, it is necessary to design a standard protocol to study the toxicity of CeO₂-NPs. Physicochemical properties of nanoparticles, experiment set up, and toxicity assessment methods are some parameters that should be considered in this standardization.     

Evaluation of the Effects of Ag,Cu, ZnO and TiO2 Nanoparticles on the Expression Level of Oxidative Stress-Related Genes and the Activity of Antioxidant Enzymes in Escherichia coli,Bacillus cereus and Staphylococcus epidermidis

Although the molecular response of bacteria exposed to metal nanoparticles (NPs) is intensively studied, many phenomena related to their survival, metal uptake, gene expression and protein production are not fully understood. Therefore, this work aimed to study Ag-NPs, Cu-NPs, ZnO-NPs and TiO₂-NPs-induced alterations in the expression level of selected oxidative stress-related genes in connection with the activity of antioxidant enzymes: catalase (CAT), peroxidase (PER) and superoxide dismutase (SOD) in Escherichia coli, Bacillus cereus and Staphylococcus epidermidis. The methodology used included: the extraction of total RNA and cDNA synthesis, the preparation of primers for selected housekeeping and oxidative stress genes, RT-qPCR reaction and the measurements of CAT, PER and SOD activities. It was established that the treatment of E. coli and S. epidermidis with NPs resulted mainly in the down-regulation of targeted genes, whilst the up-regulation of genes was confirmed in B. cereus. The greatest differences in the relative expression levels of tested genes occurred in B. cereus and S. epidermidis treated with TiO₂-NPs, while in E. coli, they were observed under ZnO-NPs exposure. The changes found were mostly related to the expression of genes encoding proteins with PER and CAT-like activity. Among NPs, ZnO-NPs and Cu-NPs increased the activity of antioxidants in E. coli and B. cereus. In turn, TiO₂-NPs had a major effect on enzymes activity in S. epidermidis. Considering all of the collected results for tested bacteria, it can be emphasised that the impact of NPs on the antioxidant system functioning was dependent on their type and concentration.     

An Anti-inflammatory Fe3O4-Porphyrin Nanohybrid Capable of Apoptosis through Upregulation of p21 Kinase Inhibitor Having Immunoprotective Properties under Anticancer PDT Conditions

We report the influence of Fe₃O₄ nanoparticles (NPs) on porphyrins in the development of photosensitizers (PSs) for efficient photodynamic therapy (PDT) and possible post-PDT responses for inflicting cancer cell death. Except for Au, most metal-based nanomaterials are unsuitable for clinical applications. The US Food and Drug Administration and other agencies have approved Feraheme and a few other iron oxide NPs for clinical use, paving the way for novel biocompatible immunoprotective superparamagnetic iron oxide nanohybrids to be developed as nanotherapeutics. A water-soluble nanohybrid, referred to here as E-NP, comprising superparamagnetic Fe₃O₄ NPs functionalised with tripyridyl porphyrin PS was introduced through a rigid 4-carboxyphenyl linker. As a PDT agent, the efficacy of E-NP toward the AGS cancer cell line showed enhanced photosensitising ability as determined through in vitro photobiological assays. The cellular uptake of E-NPs by AGS cells led to apoptosis by upregulating ROS through cell-cycle arrest and loss of mitochondrial membrane potential. The subcellular localisation of the PSs in mitochondria stimulated apoptosis through upregulation of p21, a proliferation inhibitor capable of preventing tumour development. Under both PDT and non-PDT conditions, this nanohybrid can act as an anti-inflammatory agent by decreasing the production of NO and superoxide ions in murine macrophages, thus minimising collateral damage to healthy cells.     

Insight into the Antibacterial Activity of Selected Metal Nanoparticles and Alterations within the Antioxidant Defence System in Escherichia coli,Bacillus cereus and Staphylococcus epidermidis

The antimicrobial activity of nanoparticles (NPs) is a desirable feature of various products but can become problematic when NPs are released into different ecosystems, potentially endangering living microorganisms. Although there is an abundance of advanced studies on the toxicity and biological activity of NPs on microorganisms, the information regarding their detailed interactions with microbial cells and the induction of oxidative stress remains incomplete. Therefore, this work aimed to develop accurate oxidation stress profiles of Escherichia coli, Bacillus cereus and Staphylococcus epidermidis strains treated with commercial Ag-NPs, Cu-NPs, ZnO-NPs and TiO₂-NPs. The methodology used included the following determinations: toxicological parameters, reactive oxygen species (ROS), antioxidant enzymes and dehydrogenases, reduced glutathione, oxidatively modified proteins and lipid peroxidation. The toxicological studies revealed that E. coli was most sensitive to NPs than B. cereus and S. epidermidis. Moreover, NPs induced the generation of specific ROS in bacterial cells, causing an increase in their concentration, which further resulted in alterations in the activity of the antioxidant defence system and protein oxidation. Significant changes in dehydrogenases activity and elevated lipid peroxidation indicated a negative effect of NPs on bacterial outer layers and respiratory activity. In general, NPs were characterised by very specific nano-bio effects, depending on their physicochemical properties and the species of microorganism.     

Thermal and mechanical properties of epoxy resin reinforced with modified iron oxide nanoparticles

Epoxy polymers, having good mechanical properties and thermal stability, are often used for engineering applications. Their properties can be further enhanced by the addition of iron oxide (Fe₃O₄) nanoparticles (NPs) as fillers to the resin. In this study, pristine Fe₃O₄ NPs were functionalized with polydopamine (PDA), (3-glycidoxypropyl)trimethoxysilane (GPTMS), and (3-aminopropyl)trimethoxysilane (APTES). X-ray diffraction and scanning electron microscopy (SEM) were used to study any changes in the crystal structure and size of the NPs while Fourier-Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA) were used to ensure the presence of functional groups on the surface. The mechanical properties of the Fe₃O₄-based nanocomposites generally improved except when reinforced with Fe₃O₄/PDA. The maximum improvement in tensile strength (∼34%) and fracture toughness (∼13%) were observed for pristine Fe₃O₄-based nanocomposites. Dynamic mechanical analysis (DMA) showed that the use of any of the treated NPs improved the material's initial storage modulus and had a substantial impact on its dissipation potential. Also, it was observed that the glass transition temperature measurements by DMA and differential scanning calorimetry were below that of pure epoxy. SEM of the cracked surfaces shows that the incorporation of any NPs leads to an enhancement in its thermal and mechanical properties.     

Application of magnetic polyaniline nanocomposite for separation of uranyl ions from aqueous solutions

Polyaniline (PANI) was synthesized chemically, and then modified with magnetic iron oxide nanoparticles (Fe₃O₄ NPs). PANI and PANI-Fe₃O₄ NPs were used for removal of uranyl ions (UO₂²⁺) from aqueous solutions using a batch system. The synthesized adsorbents were characterized using FT-IR, SEM, BET and XRD techniques. From isotherm investigation, the maximum adsorption capacities (q_m) were 150.0 and 108.0 mg g^?1 for PANI and PANI-Fe₃O₄NPs, respectively. The kinetics and equilibrium adsorptions were well-described by the pseudo-second-order kinetic and Langmuir model, respectively. Thermodynamic studies depicted that the adsorption of uranyl ions by PANI is a spontaneous exothermic process and in the case of PANI-Fe₃O₄ NPs, adsorption process is endothermic; therefore, the spontaneity is controlled by entropy.     

Magnetic resonance imaging of glioma with novel APTS-coated superparamagnetic iron oxide nanoparticles

We report in vitro and in vivo magnetic resonance (MR) imaging of C6 glioma cells with a novel acetylated 3-aminopropyltrimethoxysilane (APTS)-coated iron oxide nanoparticles (Fe₃O₄ NPs). In the present study, APTS-coated Fe₃O₄ NPs were formed via a one-step hydrothermal approach and then chemically modified with acetic anhydride to generate surface charge-neutralized NPs. Prussian blue staining and transmission electron microscopy (TEM) data showed that acetylated APTS-coated Fe₃O₄ NPs can be taken up by cells. Combined morphological observation, cell viability, and flow cytometric analysis of the cell cycle indicated that the acetylated APTS-coated Fe₃O₄ NPs did not significantly affect cell morphology, viability, or cell cycle, indicating their good biocompatibility. Finally, the acetylated APTS-coated Fe₃O₄ nanoparticles were used in magnetic resonance imaging of C6 glioma. Our results showed that the developed acetylated APTS-coated Fe₃O₄ NPs can be used as an effective labeling agent to detect C6 glioma cells in vitro and in vivo for MR imaging. The results from the present study indicate that the developed acetylated APTS-coated Fe₃O₄ NPs have a potential application in MR imaging.     

Preparation of stable magnetic nanofluids containing Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>@PPy nanoparticles by a novel one-pot route

Stable magnetic nanofluids containing Fe₃O₄@Polypyrrole (PPy) nanoparticles (NPs) were prepared by using a facile and novel method, in which one-pot route was used. FeCl₃·6H₂O was applied as the iron source, and the oxidizing agent to produce PPy. Trisodium citrate (Na₃cit) was used as the reducing reagent to form Fe₃O₄ NPs. The as-prepared nanofluid can keep long-term stability. The Fe₃O₄@PPy NPs can still keep dispersing well after the nanofluid has been standing for 1 month and no sedimentation is found. The polymerization reaction of the pyrrole monomers took place with Fe³⁺ ions as the initiator, in which these Fe³⁺ ions remained in the solution adsorbed on the surface of the Fe₃O₄ NPs. Thus, the core-shell NPs of Fe₃O₄@PPy were obtained. The particle size of the as-prepared Fe₃O₄@PPy can be easily controlled from 7 to 30 nm by the polymerization reaction of the pyrrole monomers. The steric stabilization and weight of the NPs affect the stability of the nanofluids. The as-prepared Fe₃O₄@PPy NPs exhibit superparamagnetic behavior.     

Ultrafine palladium nanoparticle-bonded to polyetheylenimine grafted reduced graphene oxide nanosheets: Highly active and recyclable catalyst for degradation of dyes and pigments

Much attention has been increasingly focused on the applications of noble metal nanoparticles (NPs) for the catalytic degradation of various dyes and pigments in industrial wastewater. We have demonstrated that Pd NPs/Fe₃O₄-PEI-RGO nanohybrids exhibit high catalytic activity and excellent durability in reductive degradation of MO, R6G, RB. Specific surface area was successfully prepared by simultaneous reduction of Pd(OAc)₂ chelating to PEI grafted graphene oxide nanosheets modified with Fe₃O₄. The as-prepared Pd NPs/Fe₃O₄-PEI-RGO nanohybrids were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, high-resolution TEM and energy dispersive X-ray spectroscopy, and UV-lambda 800 spectrophotometer, respectively. The catalytic activity of Pd NPs/Fe₃O₄-PEI-RGO nanohybrids to the degradation of MO, R6G, RB with NaBH4 was tracked by UV-visible spectroscopy. It was clearly demonstrated that Pd NPs/Fe₃O₄-PEI-RGO nanohybrids exhibited high catalytic activity toward the degradation of dyes and pigments, which could be relevant to the high surface areas of Pd NPs and synergistic effect on transfer of electrons between reduced graphene oxide (RGO), PEI and Pd NPs. Notably, Pd NPs/Fe₃O₄-PEI-RGO nanohybrids were easily separated and recycled thirteen times without obvious decrease in system. Convincingly, Pd NPs/Fe₃O₄-PEI-RGO nanohybrids would be a promising catalyst for treating industrial wastewater.     

Magnetic properties of superparamagnetic nanoparticles loaded into silicon nanotubes

In this work, the magnetic properties of silicon nanotubes (SiNTs) filled with Fe₃O₄ nanoparticles (NPs) are investigated. SiNTs with different wall thicknesses of 10 and 70 nm and an inner diameter of approximately 50 nm are prepared and filled with superparamagnetic iron oxide nanoparticles of 4 and 10 nm in diameter. The infiltration process of the NPs into the tubes and dependence on the wall-thickness is described. Furthermore, data from magnetization measurements of the nanocomposite systems are analyzed in terms of iron oxide nanoparticle size dependence. Such biocompatible nanocomposites have potential merit in the field of magnetically guided drug delivery vehicles.

PACS

61.46.Fg; 62.23.Pq; 75.75.-c; 75.20.-g     

Non-Covalent Synthesis of Metal Oxide Nanoparticle–Heparin Hybrid Systems: A New Approach to Bioactive Nanoparticles

Heparin has been conjugated to Fe₃O₄, Co₃O₄, and NiO nanoparticles (NPs) through electrostatic interactions, producing colloidal suspensions of hybrid metal oxide heparin NPs that are stable in water. Negative zeta potentials and retention of heparin’s ability to capture toluidine blue indicate that heparin’s negative charges are exposed on the surface of the coated NPs. IR results confirmed the formation of nanohybrids as did NMR experiments, which were also interpreted on the basis of toluidine blue tests. Transmission electron microscopy results revealed that the heparin coating does not modify the shape or dimension of the NPs. Dynamic light scattering and negative zeta potential measurements confirmed that heparin surface functionalisation is an effective strategy to prevent NP aggregation.     

Nickel Nanoparticles Exposure and Reproductive Toxicity in Healthy Adult Rats

Nickel is associated with reproductive toxicity. However, the reproductive toxicity of nickel nanoparticles (Ni NPs) is unclear. Our goal was to determine the association between nickel nanoparticle exposure and reproductive toxicity. According to the one-generation reproductive toxicity standard, rats were exposed to nickel nanoparticles by gavage and we selected indicators including sex hormone levels, sperm motility, histopathology, and reproductive outcome etc. Experimental results showed nickel nanoparticles increased follicle stimulating hormone (FSH) and luteinizing hormone (LH), and lowered etradiol (E₂) serum levels at a dose of 15 and 45 mg/kg in female rats. Ovarian lymphocytosis, vascular dilatation and congestion, inflammatory cell infiltration, and increase in apoptotic cells were found in ovary tissues in exposure groups. For male rats, the weights decreased gradually, the ratio of epididymis weight over body weight increased, the motility of rat sperm changed, and the levels of FSH and testosterone (T) diminished. Pathological results showed the shedding of epithelial cells of raw seminiferous tubule, disordered arrangement of cells in the tube, and the appearance of cell apoptosis and death in the exposure group. At the same time, Ni NPs resulted in a change of the reproductive index and the offspring development of rats. Further research is needed to elucidate exposure to human populations and mechanism of actions.     

Histidine-Assisted Synthesis and Cellular Compatibility of Magnetic Cobalt Oxide Nanoparticles at Room Temperature

Magnetic nanoparticles (NPs) of cobalt oxide (Co₃O₄) with the diameter of 20–40 nm have been prepared by a simple liquid deposition method in the Histidine (His) assistance at room temperature. Ethanol plays an important role in the preparation of cobalt oxide NPs with a polycrystalline structure. The growth mechanism for Co₃O₄ cube particles has been preliminarily explained. The hysteresis loop of NPs reveals their good magnetic property indicating that they can be used in hyperthermia, cell separation etc. These applications need the magnetic particles with cytocompatible properties. The analysis of IR spectrum, TG curve and HRTEM image indicated that cobalt oxide particles was conjugated with the His molecules. Escherichia coli (E. coli) and L929 cells tests suggest a good cellular compatibility at a concentration of less than 0.25 mg/mL, indicating that the prepared Co₃O₄ NPs have a potential for several biomedical applications.     

pH-responsive polymer in a core–shell magnetic structure as an efficient carrier for delivery of doxorubicin to tumor cells

A pH-responsive polymer derived from polyethyleneimine with zwitterionic function was used as a shell around super paramagnetic iron oxide nanoparticles (SPIONs), to introduce an efficient drug carrier for cancer drug delivery and imaging. Core–shell magnetic Fe₃O₄@FA-PEI-SUC (SUC: Succinate conjugated) nanoparticles were attained and characterized. Right chemical attachments, 61.34% modification of primary amino groups of poly(ethyleneimine) (PEI) in PEI–SUC, spherical shape, core–shell structure, crystal structure of SPIONs, 18.23% polymer coating of NPs, 8% decrease in magnetization following polymer coating around SPIONs, doxorubicin loading efficiency 85.19%, two times more released amount in acidic pH, and proper toxicity results were obtained by different analysis methods.     

Gamma irradiation-induced modifications in the structural,thermal, and optical properties of polyvinyl alcohol-polyethylene glycol/cobalt oxide nanocomposite films

Cobalt oxide nanoparticles (NPs) are highly consistent dispersed into the blend polymers rather than other NPs. Also, the ability of polyvinyl alcohol-polyethylene glycol (PVA-PEG) to form homogenous blend attained it essential characteristics that allow it to be suitable candidate for numerous industrial applications. Thus in the present work, Co₃O₄ nano-oxide, was synthesized by the sol-gel procedure and PVA-PEG/Co₃O₄ nanocomposite NCP films were synthesized by the casting technique. Samples from the synthesized NCP were exposed to γ doses between 20 and 230 kGy. The induced alterations in the synthesized NCP due to gamma irradiation have been illustrated using X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA), Fourier transform infrared (FTIR), and UV spectroscopes. Further, Color divergence between the blank and the irradiated films has been estimated. Gamma doses between 60 and 230 kGy lead to the prevalence of intermolecular crosslinking, which enhances the disordered phase. This is reflected in a rise in the degradation temperature values from 225°C to 236°C indicating an improvement in the thermostability of the NCP samples. Moreover, the γ-radiation induces defects that split the ordered portion, reducing T_m from 238°C to 229°C. In addition, the band gap decreases from 5.24 to 4.61 eV with increasing the γ doses to 230 kGy, signifying disorder character. Finally, the NCP samples showed a color change by γ radiation, as ΔE raised with increasing dose. The resultant improvements in the optical properties of the NCP samples allow it to be used in optoelectronic and dosimetric applications.     

Synthesis of graphene nanosheets modified with the Fe3O4@ phenol formaldehyde resin or PFR nanoparticles for their application in bio‐imagine and thermal treatment

Two different types of graphene‐based composites have been synthesized with simple assays. The multifunctional composites were obtained through loading Fe₃O₄@phenol formaldehyde resin (PFR) nanoparticles (NPs) synthesized with Fe₃O₄ NPs, hexamethylene‐tetramine, and phenol onto the surface of graphene oxide sheets in the presence of coupling agent. The Fe₃O₄@PFR loaded graphene oxide composites bring several merits. It prevents PFR NPs aggregation due to the existed graphene oxide but also endows the composites photothermal conversion property. Furthermore, the graphene‐wrapped PFR composites were prepared by mixing oxide graphene and PFR NPs at 110 °C by means of the good reduction of the hydroxyl group on the surface of PFR NPs to graphene. Under the assistance of chitosan, a building block consists of graphene‐wrapped PFR composites could be obtained. Thus, an ideal method may be developed to synthesize graphene‐wrapped PFR composites for constructing building blocks. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45007.