Cytotoxicity and oxidative stress induced by different metallic nanoparticles on human kidney cells

Background  

Some manufactured nanoparticles are metal-based and have a wide variety of applications in electronic, engineering and medicine. Until now, many studies have described the potential toxicity of NPs on pulmonary target, while little attention has been paid to kidney which is considered to be a secondary target organ. The objective of this study, on human renal culture cells, was to assess the toxicity profile of metallic nanoparticles (TiO₂, ZnO and CdS) usable in industrial production. Comparative studies were conducted, to identify whether particle properties impact cytotoxicity by altering the intracellular oxidative status.     

Genotoxic responses to titanium dioxide nanoparticles and fullerene in gpt delta transgenic MEF cells

Background  

Titanium dioxide (TiO₂) nanoparticles and fullerene (C₆₀) are two attractive manufactured nanoparticles with great promise in industrial and medical applications. However, little is known about the genotoxic response of TiO₂ nanoparticles and C₆₀ in mammalian cells. In the present study, we determined the mutation fractions induced by either TiO₂ nanoparticles or C₆₀ in gpt delta transgenic mouse primary embryo fibroblasts (MEF) and identified peroxynitrite anions (ONOO^-) as an essential mediator involved in such process.     

A dose-controlled system for air-liquid interface cell exposure and application to zinc oxide nanoparticles

Background  

Engineered nanoparticles are becoming increasingly ubiquitous and their toxicological effects on human health, as well as on the ecosystem, have become a concern. Since initial contact with nanoparticles occurs at the epithelium in the lungs (or skin, or eyes), in vitro cell studies with nanoparticles require dose-controlled systems for delivery of nanoparticles to epithelial cells cultured at the air-liquid interface.     

Asbestos, carbon nanotubes and the pleural mesothelium: a review of the hypothesis regarding the role of long fibre retention in the parietal pleura, inflammation and mesothelioma

Background

Increasing environmental and occupational exposures to nanoparticles (NPs) warrant deeper insight into the toxicological mechanisms induced by these materials. The present study was designed to characterize the cell death induced by carbon black (CB) and titanium dioxide (TiO₂) NPs in bronchial epithelial cells (16HBE14o- cell line and primary cells) and to investigate the implicated molecular pathways.

Results

Detailed time course studies revealed that both CB (13 nm) and TiO₂(15 nm) NP exposed cells exhibit typical morphological (decreased cell size, membrane blebbing, peripheral chromatin condensation, apoptotic body formation) and biochemical (caspase activation and DNA fragmentation) features of apoptotic cell death. A decrease in mitochondrial membrane potential, activation of Bax and release of cytochrome c from mitochondria were only observed in case of CB NPs whereas lipid peroxidation, lysosomal membrane destabilization and cathepsin B release were observed during the apoptotic process induced by TiO₂ NPs. Furthermore, ROS production was observed after exposure to CB and TiO₂ but hydrogen peroxide (H₂O₂) production was only involved in apoptosis induction by CB NPs.

Conclusions

Both CB and TiO₂ NPs induce apoptotic cell death in bronchial epithelial cells. CB NPs induce apoptosis by a ROS dependent mitochondrial pathway whereas TiO₂ NPs induce cell death through lysosomal membrane destabilization and lipid peroxidation. Although the final outcome is similar (apoptosis), the molecular pathways activated by NPs differ depending upon the chemical nature of the NPs.     

Surface Composition and Catalytic Evolution of Au x Pd1−x (x = 0.25, 0.50 and 0.75) Nanoparticles Under CO/O2 Reaction in Torr Pressure Regime and at 200 °C

Abstract  

Au _x Pd_1−x (x = 0, 0.25, 0.5, 0.75, 1) nanoparticle (NP) catalysts (8–11 nm) were synthesized by a one-pot reaction strategy using colloidal chemistry. XPS depth profiles with variable X-ray energies and scanning transmission electron microscopy (STEM) analyses show that the as-synthesized Au _x Pd_1−x (x = 0.25 and 0.5) bimetallic NPs have gradient alloy structures with Au-rich cores and Pd-rich shells. The evolution of composition and structure in the surface region corresponding to a mean free path of 0.6–0.8 nm (i.e., 2–3 layers to the bulk from the particle surface) was studied with ambient pressure X-ray photoelectron spectroscopy (AP-XPS) under CO/O₂ reaction in the Torr pressure regime. Under the reaction conditions of 80 mTorr CO and 200 mTorr O₂ at 200 °C, the surface region of Au_0.75Pd_0.25 NP is Au-rich (~70% by Au). All Au _x Pd_1−x (x = 0.25, 0.5, 0.75) NP catalysts have higher turnover rates for the model CO/O₂ reaction than pure Pd and pure Au NPs. The Pd-rich Au_0.25Pd_0.75 NPs show the highest turnover rates and the Pd-rich Au_0.5Pd_0.5 NPs the lowest turnover rates at 200 °C. Interestingly, the Au-rich Au_0.75Pd_0.25 NPs exhibit steady-state turnover rates which are intermediate to those of the Pd-rich bimetallic nanoparticles.     

ETS-10 Supported Au Nanoparticles for Solvent-Free Oxidation of 1-Phenylethanol with Oxygen

Abstract  

Au nanoparticles (NPs) were uniformly dispersed on ETS-10 titanosilicate using the cation exchange procedure and [Au(NH₃)₄](NO₃)₃ complex as the gold source. [Au(NH₃)₄]³⁺ cations were first introduced inside ETS-10 micropores, ligands were then released, Au³⁺ was reduced to Au⁺ forming electron-deficient Au clusters, and finally aggregation to Au NPs occurred. In comparison to the incipient-wetness and deposition–precipitation methods, the ion-exchange led to greater activity of the Au NPs in the oxidation of 1-phenylethanol by oxygen.     

Neuroinflammation is induced by tongue-instilled ZnO nanoparticles via the Ca<Superscript>2+</Superscript>-dependent NF-κB and MAPK pathways

Background

The extensive biological applications of zinc oxide nanoparticles (ZnO NPs) in stomatology have created serious concerns about their biotoxicity. In our previous study, ZnO NPs were confirmed to transfer to the central nervous system (CNS) via the taste nerve pathway and cause neurodegeneration after 30 days of tongue instillation. However, the potential adverse effects on the brain caused by tongue-instilled ZnO NPs are not fully known.

Methods

In this study, the biodistribution of Zn, cerebral histopathology and inflammatory responses were analysed after 30 days of ZnO NPs tongue instillation. Moreover, the molecular mechanisms underlying neuroinflammation in vivo were further elucidated by treating BV2 and PC12 cells with ZnO NPs in vitro.

Results

This analysis indicated that ZnO NPs can transfer into the CNS, activate glial cells and cause neuroinflammation after tongue instillation. Furthermore, exposure to ZnO NPs led to a reduction in cell viability and induction of inflammatory response and calcium influx in BV2 and PC12 cells. The mechanism underlying how ZnO NPs induce neuroinflammation via the Ca²⁺-dependent NF-κB, ERK and p38 activation pathways was verified at the cytological level.

Conclusion

This study provided a new way how NPs, such as ZnO NPs, induce neuroinflammation via the taste nerve translocation pathway, a new mechanism for ZnO NPs-induced neuroinflammation and a new direction for nanomaterial toxicity analysis.

     

Synthesis of Calcium Phosphate Nanoparticle‐Based Docetaxel Delivery System and its In Vitro Anticancer Activity

A new docetaxel (DTX) delivery system has been prepared based on calcium phosphate nanoparticles (CaP NPs) and obtained DTX‐adsorbed CaP NPs. The DTX‐adsorbed CaP NPs were nearly spherical with mean diameter about 200 nm and a negative zeta potential of ?18.8 ± 0.5 mV. They can be well dispersed and stable in water for a long time. In addition, the DTX‐adsorbed CaP NPs showed higher cytotoxicity in human nonsmall‐cell lung cancer (NSCLC) cell lines than that of DTX at the same experimental conditions. Thus, it could be concluded that CaP NPs can be a promising DTX delivery vehicle in NSCLC chemotherapy.     

Phytoextract-mediated synthesis of Cu doped NiO nanoparticle using cullon tomentosum plant extract with efficient antibacterial and anticancer property

In the present study, nickel oxide (NiO) and copper-doped nickel oxide (NiCuO) nanoparticles (NPs) were successfully synthesized using Cullen tomentosum plant extract with the co-precipitation method. This work focuses on the Phyto-mediated synthesis and characterization of NPs for their biological applications. Phytochemicals that exist in the plant extract acts as reducing and capping agent. The successful formation of the NPs was validated by various analysis as XRD, FESEM, EDAX, FT-IR, UV–Vis, and Photoluminescence. According to XRD studies, the average crystallite size of NiO and NiCuO NPs is 36 nm and 31 nm, respectively. The river stone and nanoflower like morphology for NiO and NiCuO NPs are confirmed by FESEM image. Furthermore, the synthesized NPs were tested against Gram-positive (Bacillus subtilis, Streptococcus pneumoniae) and Gram-negative (Klebsiella pneumoniae, Escherichia coli) bacteria, which showed enhanced antibacterial activity of NiCuO NPs. The cytotoxicity of NPs was investigated against human breast cancer cells (MDA-MB-231) and fibroblast L929 cell lines. Also, the IC₅₀ value for human breast cancer cells is 11.8 μg/mL. According to these findings, NiCuO NPs are potential nanomaterials with advanced healthcare uses.     

A comparison of dispersing media for various engineered carbon nanoparticles

Background  

With the increased manufacture and use of carbon nanoparticles (CNP) there has been increasing concern about the potential toxicity of fugitive CNP in the workplace and ambient environment. To address this matter a number of investigators have conducted in vitro and in vivo toxicity assessments. However, a variety of different approaches for suspension of these particles (culture media, Tween 80, dimethyl sulfoxide, phosphate-buffered saline, fetal calf serum, and others), and different sources of materials have generated potentially conflicting outcomes. The quality of the dispersion of nanoparticles is very dependent on the medium used to suspend them, and this then will most likely affect the biological outcomes.     

Antimicrobial Properties of Palladium and Platinum Nanoparticles: A New Tool for Combating Food-Borne Pathogens

Although some metallic nanoparticles (NPs) are commonly used in the food processing plants as nanomaterials for food packaging, or as coatings on the food handling equipment, little is known about antimicrobial properties of palladium (PdNPs) and platinum (PtNPs) nanoparticles and their potential use in the food industry. In this study, common food-borne pathogens Salmonella enterica Infantis, Escherichia coli, Listeria monocytogenes and Staphylococcus aureus were tested. Both NPs reduced viable cells with the log₁₀ CFU reduction of 0.3–2.4 (PdNPs) and 0.8–2.0 (PtNPs), average inhibitory rates of 55.2–99% for PdNPs and of 83.8–99% for PtNPs. However, both NPs seemed to be less effective for biofilm formation and its reduction. The most effective concentrations were evaluated to be 22.25–44.5 mg/L for PdNPs and 50.5–101 mg/L for PtNPs. Furthermore, the interactions of tested NPs with bacterial cell were visualized by transmission electron microscopy (TEM). TEM visualization confirmed that NPs entered bacteria and caused direct damage of the cell walls, which resulted in bacterial disruption. The in vitro cytotoxicity of individual NPs was determined in primary human renal tubular epithelial cells (HRTECs), human keratinocytes (HaCat), human dermal fibroblasts (HDFs), human epithelial kidney cells (HEK 293), and primary human coronary artery endothelial cells (HCAECs). Due to their antimicrobial properties on bacterial cells and no acute cytotoxicity, both types of NPs could potentially fight food-borne pathogens.     

Comparative toxicity of 24 manufactured nanoparticles in human alveolar epithelial and macrophage cell lines

Background  

A critical issue with nanomaterials is the clear understanding of their potential toxicity. We evaluated the toxic effect of 24 nanoparticles of similar equivalent spherical diameter and various elemental compositions on 2 human pulmonary cell lines: A549 and THP-1. A secondary aim was to elaborate a generic experimental set-up that would allow the rapid screening of cytotoxic effect of nanoparticles. We therefore compared 2 cytotoxicity assays (MTT and Neutral Red) and analyzed 2 time points (3 and 24 hours) for each cell type and nanoparticle. When possible, TC50 (Toxic Concentration 50 i.e. nanoparticle concentration inducing 50% cell mortality) was calculated.     

Calcium-dependent cyto- and genotoxicity of nickel metal and nickel oxide nanoparticles in human lung cells

Background

Genotoxicity is an important toxicological endpoint due to the link to diseases such as cancer. Therefore, an increased understanding regarding genotoxicity and underlying mechanisms is needed for assessing the risk with exposure to nanoparticles (NPs). The aim of this study was to perform an in-depth investigation regarding the genotoxicity of well-characterized Ni and NiO NPs in human bronchial epithelial BEAS-2B cells and to discern possible mechanisms. Comparisons were made with NiCl₂ in order to elucidate effects of ionic Ni.

Methods

BEAS-2B cells were exposed to Ni and NiO NPs, as well as NiCl₂, and uptake and cellular dose were investigated by transmission electron microscopy (TEM) and inductively coupled plasma mass spectrometry (ICP-MS). The NPs were characterized in terms of surface composition (X-ray photoelectron spectroscopy), agglomeration (photon cross correlation spectroscopy) and nickel release in cell medium (ICP-MS). Cell death (necrosis/apoptosis) was investigated by Annexin V-FITC/PI staining and genotoxicity by cytokinesis-block micronucleus (cytome) assay (OECD 487), chromosomal aberration (OECD 473) and comet assay. The involvement of intracellular reactive oxygen species (ROS) and calcium was explored using the fluorescent probes, DCFH-DA and Fluo-4.

Results

NPs were efficiently taken up by the BEAS-2B cells. In contrast, no or minor uptake was observed for ionic Ni from NiCl₂. Despite differences in uptake, all exposures (NiO, Ni NPs and NiCl₂) caused chromosomal damage. Furthermore, NiO NPs were most potent in causing DNA strand breaks and generating intracellular ROS. An increase in intracellular calcium was observed and modulation of intracellular calcium by using inhibitors and chelators clearly prevented the chromosomal damage. Chelation of iron also protected against induced damage, particularly for NiO and NiCl₂.

Conclusions

This study has revealed chromosomal damage by Ni and NiO NPs as well as Ni ionic species and provides novel evidence for a calcium-dependent mechanism of cyto- and genotoxicity.

     

Photocrosslinkable acid urethane dimethacrylates from renewable natural oil and their use in the design of silver/gold polymeric nanocomposites

Castor oil-based acid urethane macromers were prepared and employed for obtaining Ag/Au/polymer nanocomposites. Structure and UV induced photopolymerization of the macromers were investigated by spectral methods. The polymerization rate and the degree of conversion decreased with about 10% in the presence of 2.5 wt.% silver nanoparticles (Ag NPs). For the diacid macromer, the surface plasmon intensity increased with irradiation time (the optical density of the absorption maximum (430 nm) attained 2.3 after 600 s), whereas a diminished efficiency was found for Ag NPs in situ generated. Transmission electron microscopy and X-ray photoelectron spectroscopy confirmed uniform distribution of the spherical nanoparticles (0.6 nm (Ag NPs); 5 nm (Au NPs)) and the appearance of Ag 3d_3/2, Ag 3d_5/2, Au 4f_7/2 and Au 4f_5/2 peaks corresponding to Ag (0) or Au (0). Environmental scanning electron microscope with energy-dispersive X-ray detector, contact angle and mechanical parameters measurements complemented the above observations.     

Effects of differently shaped TiO<Subscript>2</Subscript>NPs (nanospheres,nanorods and nanowires) on the <Emphasis Type="Italic">in vitro</Emphasis> model (Caco-2/HT29) of the intestinal barrier

Background

The biological effects of nanoparticles depend on several characteristics such as size and shape that must be taken into account in any type of assessment. The increased use of titanium dioxide nanoparticles (TiO₂NPs) for industrial applications, and specifically as a food additive, demands a deep assessment of their potential risk for humans, including their abilities to cross biological barriers.

Methods

We have investigated the interaction of three differently shaped TiO₂NPs (nanospheres, nanorods and nanowires) in an in vitro model of the intestinal barrier, where the coculture of Caco-2/HT29 cells confers inherent intestinal epithelium characteristics to the model (i.e. mucus secretion, brush border, tight junctions, etc.).

Results

Adverse effects in the intestinal epithelium were detected by studying the barrier’s integrity (TEER), permeability (LY) and changes in the gene expression of selected specific markers. Using Laser Scanning Confocal Microscopy, we detected a different behaviour in the bio-adhesion and biodistribution of each of the TiO₂NPs. Moreover, we were able to specifically localize each type of TiO₂NPs inside the cells. Interestingly, general DNA damage, but not oxidative DNA damage effects, were detected by using the FPG version of the comet assay.

Conclusions

Results indicate different interactions and cellular responses related to differently shaped TiO₂NPs, nanowires showing the most harmful effects.

     

Hybrid Nanoarchitectonics of Chitosan-Cerium Oxide Nanoparticles for Anticancer Potentials

The aim of this study was to synthesize green cerium oxide nanoparticles (CeO₂–NPs) and coat them with chitosan polymers to increase bioavailability and their effectiveness in anti-cancer studies. For the synthesis of CeO₂–NPs, aqueous rosemary leaf extract (RLE) was used as a reducing and stabilizing agent, and after characterizing the nanoparticles (DLS and XRD), a coating of chitosan around the nanoparticles (CeCh–NPs) was created by ionic gelation method. After characterizing (DLS, Zeta potential, FTIR and FESEM) and confirming the presence of nanoparticles, its toxicity effects were evaluated by MTT method and its pro-apoptotic effects were evaluated by qPCR (Caspase 3 and 9) and flow cytometric analysis. CeO₂–NPs were formed with uniform dispersion (PDI: 0.25) in nanometer dimensions (184.84 nm) and after coating, their size increase to 202.35 nm was confirmed by DLS method. The CeCh–NPs were spherical, stable (ζ potential:?+?35.4 mV) and uniformly dispersed (PDI: 0.27). The median concentrations of nanoparticles against AGS, A459, PC3 and HFF cells were reported to be about 156.02, 169.1, 155.8 and 307.5 μg/ml. Increased expression of caspase 3 and 9 genes as well as increased percentage of SubG1 phase cells in flow cytometry confirmed the occurrence of apoptosis in treated cells. The results of this study confirmed the anticancer properties of CeCh–NPs by relying on the apoptosis process.

     

In vitro anticancer activity and comparative green synthesis of ZnO/Ag nanoparticles by moringa oleifera,mentha piperita,and citrus lemon

This study proposes a simple, effective, and environmentally friendly approach for the synthesis of zinc oxide/silver nanoparticles (ZnO/Ag NPs) using three different plant extracts. The plants used in this study were moringa oleifera (MO), mentha piperita (MP), and citrus lemon (CL). Characterizations of ZnO/Ag NPs were done using ultraviolet–visible spectroscopy (UV vis), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) along with energy dispersive spectroscopy (EDX), and fourier transform infrared spectroscopy (FTIR). In accordance with size distribution findings, ZnO/Ag NPs synthesized with MO have a narrow size distribution, with the average particle size being 119 ± 36 nm. Among these three reducing agent MO act as the best reducing agent. Moreover, the anticancer activity of silver nanoparticles (Ag NPs), zinc oxide nanoparticles (ZnO NPs) and ZnO/Ag NPs synthesized with MO were demonstrated in human cervical cancer cells (HeLA). The results revealed that ZnO/Ag NPs demonstrate in vitro cell viability of 72%, 81%, and 84% using 2.5, 5, and 10 μgml^?1of ZnO/Ag NPs for 24 h. While Ag NPs and ZnO NPs prepared with MO showed 50% and 60% cell viability using 2.5 μgml^?1concentration for 24 h. This showed that the ZnO/Ag NPs act as a strong anticancer agent compared to Ag NPs and ZnO NPs. Overall, this research proposes a green synthesis approach for ZnO/Ag NPs with a wide range of potential uses, particularly in biomedicine.     

Stability and cytotoxicity study of NiFe2O4 nanocomposites synthesized by co-precipitation and subsequent thermal annealing

In this article, NiFe₂O₄ nanoparticles (NPs) were prepared by co-precipitation method with subsequent thermal annealing leading to obtainment NPs with average sizes of 78 nm. Structure and magnetic analysis were performed by X-ray diffraction, transmission electron microscopy, Mössbauer spectroscopy and vibrating sample magnetometry techniques. Stability of NiFe₂O₄ NPs was evaluated in PBS solution during 20 days. The toxicity of prepared NPs was evaluated in vitro using different cancer cell lines: HeLa (cervical cancer cell), PC-3 (prostate cancer cell). Fibroblasts like cells of L929 obtained from subcutaneous adipose tissue of mouse were used as normal cells. Results indicate successful synthesis of NiFe₂O₄ NPs that exhibit low cytotoxicity in concentration range from 1 to 100 μg/ml. Presented physical and biological results indicate the possibility of application investigated magnetic nanoparticles in hyperthermia, targeted drug delivery, magnetic resonance imaging or cell separation.     

Self synthesize of silver nanoparticles in/on polyurethane nanofibers: Nano‐biotechnological approach

In this study, we are introducing a new class of Polyurethane (PU) nanofibers containing silver nanoparticles (NPs) by electrospinning. A simple method not depending on the addition of foreign chemicals has been used to self‐synthesize of silver NPs in/on PU nanofibers. Typically, a sol?gel consisting of AgNO₃/PU/N,N‐dimethylformamide (DMF) has been electrospun and aged for a week, so silver NPs have been created in/on PU nanofibers. Syntheses of silver NPs were carried out by exploiting the reduction ability of the DMF solvent which is the main constituent to obtain PU electrospun nanofibers in decomposition of silver nitrate precursor into silver NPs. Physiochemical characterizations confirmed well oriented nanofibers and good dispersing of pure silver NPs. Various parameters affecting utilizing of the prepared nanofibers on various nano‐biotechnological fields have been studied. For instance, the obtained nanofiber mats were checked for mechanical properties which showed the improvement of the tensile strength upon increase in silver NPs content. Moreover, the nanofibers were subjected to 10 times successive washing experiments with using solid to liquid ratio of 3 : 5000 for 25 h, UV spectroscopy analysis reveals no losses of silver NPs from the PU nanofibers. 3T3‐L1 fibroblasts were cultured in presence of the designed nanofibers. The morphological features of the cells attached on nanofibers were examined by BIO‐SEM, which showed well attachment of cells to fibrous mats. The cytotoxicity results indicated absence of toxic effect on the 3T3‐L1 cells after cell culturing. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Ultrahigh Active Pd Nanocatalyst Supported on Core-Sheath Conducting Polymer/Metal Oxide Composite Nanorods

Abstract  

A facile and aqueous-phase method based on the electron transfer reduction process for fabricating core-sheath structured polyaniline (PANI)/SnO₂ composite nanorods supported Pd nanocatalyst has been demonstrated. The Pd nanoparticles synthesized by this strategy have a small size of smaller than 3.0 nm. The well dispersed Pd nanoparticles with small sizes supported on core-sheath PANI/SnO₂ composite nanorods exhibited an ultrahigh catalytic activity during the catalytic reduction of p-nitrophenol into p-aminophenol by NaBH₄ in aqueous solution. The kinetic apparent rate constant (k_app) reach to be about 26.9 × 10⁻³ s⁻¹. It is believed that this method could be extended to cover many kinds of other functional composite nanomaterials where the active component is expected to bring in new features and applications.