Cytotoxicity of vanadium oxide nanoparticles and titanium dioxide-coated vanadium oxide nanoparticles to human lung cells

Macrophage Responses to Multicore Encapsulated Iron Oxide Nanoparticles for Cancer Therapy

Macrophages are the primary cells responsible for nanoparticle processing and mediating host immunological biological outcomes. Their cellular response to nanoparticles is a vital constituent in the safety assessment of new designs for clinical application. An approach for the treatment of solid tumors was developed, based on magnetic hyperthermia, consisting of iron oxide multicore encapsulated nanoparticles named Sarah nanoparticles (SaNPs), and alternating magnetic field irradiation. SaNPs are intravenously injected, accumulate in the liver, spleen and in tumor tissue, where they are passively targeted to malignant cells via the Enhanced Permeability and Retention (EPR) effect and undergo selective heating. SaNP-induced responses after cellular uptake were investigated in murine RAW264.7 macrophages using a wide imaging approach. When activated, macrophages form different phenotypic populations with unique immune functions, however the mechanism/s by which these activated macrophages respond to nanoparticles is unclear. Unraveling these responses is important for the understanding of nanoparticle uptake, potential degradation, and clearance to address both toxicity and regulatory concerns, which was the aim of this study. The results demonstrated that SaNPs undergo internalization, localize within the lysosomal compartment while keeping their integrity, without intracellular toxic degradation, and are cleared with time. The production of tumor necrosis factor alpha (TNF-α) and reactive oxygen species (ROS), superoxide dismutase (SOD) activation, and cytokine secretion in macrophage conditioned medium (CM) were also evaluated. SaNPs effects were both time- and dose- dependent. High SaNP concentrations resulted in reduced RAW264.7 cell viability which correlated with SOD activation and was associated with ROS generation. Lower SaNP concentrations stimulated the time-dependent production of TNF-α. The expression of additional cytokines was also induced, potentially affecting cancer cell growth by CM from SaNP-activated macrophages supporting a potential antitumor effect. These results will help understand the fate of nanoparticles in vivo.

Genotoxicity and heating Performance of VxFe3-xO4 nanoparticles in Health applications

The applications of magnetic nanoparticles (MNPs) as biocatalysts in different biomedical areas have been evolved very recently. One of the main challenges in this field is to design affective MNPs surfaces with catalytically active atomic centres, while producing minimal toxicological side effects on the hosting cell or tissues. MNPs of vanadium spinel ferrite (VFe2O4) are a promising material for mimicking the action of natural enzymes in degrading harmful substrates due to the presence of active V5+ centres. However, the toxicity of this material has not been yet studied in detail enough to grant biomedical safety. In this work, we have extensively measured the structural, compositional, and magnetic properties of a series of VxFe3-xO4 spinel ferrite MNPs to assess the surface composition and oxidation state of V atoms, and also performed systematic and extensive in vitro cytotoxicity and genotoxicity testing required to assess their safety in potential clinical applications. We could establish the presence of V5+ at the particle surface even in water-based colloidal samples at pH 7, as well as different amounts of V2+ and V3+ substitution at the A and B sites of the spinel structure. All samples showed large heating efficiency with Specific Loss Power values up to 400 W/g (H0 = 30 kA/m; f = 700 kHz). Samples analysed for safety in human hepatocellular carcinoma (HepG2) cell line with up to 24h of exposure showed that these MNPs did not induce major genomic abnormalities such as micronuclei, nuclear buds, or nucleoplasmic bridges (MNIs, NBUDs, and NPBs), nor did they cause DNA double-strand breaks (DSBs) or aneugenic effects-types of damage considered most harmful to cellular genetic material. The present study is an essential step towards the use of these type of nanomaterials in any biomedical or clinical application.

Toxicity of VO2 micro/nanoparticles to nitrogen-fixing bacterium Azotobacter vinelandii

Vanadium dioxide (VO2) has been used in a variety of products due to its outstanding phase transition properties. However, as potential heavy metal contaminants, the environmental hazards and risks of VO2 should be systematically investigated. Biological nitrogen fixation is one of the most dominant processes in biogeochemical cycle, which is associated with nitrogen-fixing bacteria. In this study, we reported the environmental bio-effects of VO2 micro/nanoparticles on the nitrogen-fixing bacterium Azotobacter vinelandii. VO2 at 10 and 30 mg/L caused severe hazards to A. vinelandii, such as cell apoptosis, oxidative damage, physical damage, genotoxicity, and the loss of nitrogen fixation activity. The up-regulated differentially expressed genes of A. vinelandii were related to stress response, and the down-regulated genes were mainly related to energy metabolism. Surprisingly, VO2 of 10 mg/L decreased the nif gene expression but elevated the vnf gene expression, which enhanced the ability of A. vinelandii to reduce acetylene in anaerobic environment. In addition, under tested conditions, VO2 nanoparticles exhibited insignificantly higher toxicity than VO2 microparticles.

Cytotoxicity of vanadium dioxide nanoparticles to human embryonic kidney cell line: Compared with vanadium(IV/V) ions

Vanadium dioxide (VO2) is a class of thermochromic material with potential applications in various fields. Massive production and wide application of VO2 raise the concern of its potential toxicity to human, which has not been fully understood. Herein, a commercial VO2 nanomaterial (S-VO2) was studied for its potential toxicity to human embryonic kidney cell line HEK293, and two most common vanadium ions, V(IV) and V(V), were used for comparison to reveal the related mechanism. Our results indicate that S-VO2 induces dose-dependent cellular viability loss mainly through the dissolved V ions of S-VO2 outside the cell rather than S-VO2 particles inside the cell. The dissolved V ions of S-VO2 overproduce reactive oxygen species to trigger apoptosis and proliferation inhibition via several signaling pathways of cell physiology, such as MAPK and PI3K-Akt, among others. All bioassays indicate that the differences in toxicity between S-VO2, V(IV), and V(V) in HEK293 cells are very small, supporting that the toxicity is mainly due to the dissolved V ions, in the form of V(V) and/or V(IV), but the V(V)'s behavior is more similar to S-VO2 according to the gene expression analysis. This study reveals the toxicity mechanism of nanosized VO2 at the molecular level and the role of dissolution of VO2, providing valuable information for safe applications of vanadium oxides.

Green Synthesis of ZnO and V-Doped ZnO Nanoparticles Using Vinca rosea Plant Leaf for Biomedical Applications

The present work focused on the synthesis of Vinca rosea leaf extract derived ZnO and vanadium-doped ZnO nanoparticles (V-ZnO NPs). The chemical composition, structural, and morphology of ZnO and vanadium-doped ZnO NPs were examined by FTIR, XRD, and SEM-EDX. The FTIR confirmed the presence of functional groups corresponding to ZnO and vanadium-doped ZnO NPs. SEM-EDX clearly indicated the morphology of synthesised NPs; the hexagonal crystal of NPs was confirmed from XRD. In addition, the cytotoxic effect of ZnO and V-ZnO NPs was estimated against the breast cancer (MCF-7) cell line. From the assay, Vinca rosea (V. rosea) capped ZnO NPs have shown improved cytotoxic activity than that of Vinca rosea capped V-ZnO NPs. ZnO and vanadium-doped ZnO NPs showed the strongest antibacterial activity against Enterococcus, Escherichia coli, Candida albicans, and Aspergillus niger. The α-amylase inhibition assays demonstrated antidiabetic activity of synthesised NPs. From the assay test, results obtained Vinca rosea capped ZnO nanoparticles prepared using the green approach showed high effective antioxidant, antidiabetic activity, and anticancer activity than vanadium-doped ZnO NPs.

The Role of p53 in Nanoparticle-Based Therapy for Cancer

p53 is arguably one of the most important tumor suppressor genes in humans. Due to the paramount importance of p53 in the onset of cell cycle arrest and apoptosis, the p53 gene is found either silenced or mutated in the vast majority of cancers. Furthermore, activated wild-type p53 exhibits a strong bystander effect, thereby activating apoptosis in surrounding cells without being physically present there. For these reasons, p53-targeted therapy that is designed to restore the function of wild-type p53 in cancer cells seems to be a very appealing therapeutic approach. Systemic delivery of p53-coding DNA or RNA using nanoparticles proved to be feasible both in vitro and in vivo. In fact, one p53-based therapeutic (gendicine) is currently approved for commercial use in China. However, the broad use of p53-based therapy in p53-inactivated cancers is severely restricted by its inadequate efficacy. This review highlights the current state-of-the-art in this area of biomedical research and also discusses novel approaches that may help overcome the shortcomings of p53-targeting nanomedicine.

Biodistribution of Vanadium Dioxide Particles in Mice by Consecutive Gavage Administration: Effects of Particle Size, Dosage, and Health Condition of Mice

The newly developed vanadium dioxide (VO₂), a material with excellent reversible and multi-stimuli responsible phase transition property, has been widely used in high-performance and energy-saving smart devices. The rapid growth of the VO₂-based emerging technologies and the complex biological effect of vanadium to organisms urge a better understanding of the behavior of VO₂ in vivo for safety purpose. Herein, we study the absorption, distribution, and excretion of two commercial VO₂ (nanoscale SVO₂ and bulk MVO₂) in mice after consecutive gavage administration for up to 28 days. The absorption of both types of VO₂ is as low as less than 1.5% of the injected dose within 28 days, while MVO₂ is several times more difficult to be absorbed than SVO₂. Almost all unabsorbed VO₂ is excreted through feces. For the absorbed vanadium, bone is the organ with the largest accumulation, followed by liver, kidney, and spleen. The vanadium content in organs shows a size-, dosage-, and animal health condition-dependent manner, and increases gradually to a saturation value along with the consecutive administration. Generally, smaller particle size and higher dosage lead to higher vanadium contents in organs, and more vanadium accumulates in bone and liver in diabetic mice than in normal mice. After the treatment is stopped, the accumulated vanadium in organs decreases a lot within 14 days, even reaches to the background level in some organs, but the content of vanadium in the bone remains high after 14 days post-exposure. These findings provide basic information for the safety assessment and safe applications of VO₂-based materials.

Rare-earth orthovanadate nanoparticles trigger Ca2+-dependent eryptosis

Introduction. Rare-earth orthovanadate nanoparticles (ReVO₄:Eu³⁺, Re = Gd, Y or La) are promising agents for photodynamic therapy of cancer due to their modifiable redox properties. However, their toxicity limits their application.Objective. The aim of this research was to elucidate pro-eryptotic effects of GdVO₄:Eu³⁺and LaVO₄:Eu³⁺nanoparticles with identification of underlying mechanisms of eryptosis induction and to determine their pharmacological potential in eryptosis-related diseases.Methods. Blood samples (n= 9) were incubated for 24 h with 0-10-20-40-80 mg l^-1GdVO₄:Eu³⁺or LaVO₄:Eu³⁺nanoparticles, washed and used to prepare erythrocyte suspensions to analyze the cell membrane scrambling (annexin-V-FITC staining), cell shrinkage (forward scatter signaling), reactive oxygen species (ROS) generation through 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) staining and intracellular Ca²⁺levels via FLUO4 AM staining by flow cytometry. Internalization of europium-enabled luminescent GdVO₄:Eu³⁺and LaVO₄:Eu³⁺nanoparticles was assessed by confocal laser scanning microscopy.Results.Both nanoparticles triggered eryptosis at concentrations of 80 mg l^-1. ROS-mediated mechanisms were not involved in rare-earth orthovanadate nanoparticles-induced eryptosis. Elevated cytosolic Ca²⁺concentrations were revealed even at subtoxic concentrations of nanoparticles. LaVO₄:Eu³⁺nanoparticles increased intracellular calcium levels in a more pronounced way compared with GdVO₄:Eu³⁺nanoparticles. Our data disclose that the small-sized (15 nm) GdVO₄:Eu³⁺nanoparticles were internalized after a 24 h incubation, while the large-sized (∼30 nm) LaVO₄:Eu³⁺nanoparticles were localized preferentially around erythrocytes.Conclusions.Both internalized GdVO₄:Eu³⁺and non-internalized LaVO₄:Eu³⁺nanoparticles (80 mg l^-1) promote eryptosis of erythrocytes after a 24 h exposurein vitrovia Ca²⁺signaling without involvement of oxidative stress. Eryptosis is a promising model for assessing nanotoxicity.

Mechanisms of the carcinogenicity of nanomaterials

Nanomaterials become more widespread in the different areas of human life, forming the new technosphere philosophy, in particular, new approaches for development and usage of these materials in everyday life, manufacture, medicine etc.The physicochemical characteristics of nanomaterials differ significantly from the corresponding indicators of aggregate materials and at least some of them are highly reactive and / or highly catalytic. This suggests their aggressiveness towards biological systems, including involvement in carcinogenesis. The review considers the areas of use of modern nanomaterials, with special attention paid to the description of medicine production using nanotechnologies, an analysis of the mechanisms of action of a number of nanomaterials already recognized as carcinogenic, and also presents the available experimental and mechanistic data obtained from the study of the carcinogenic / procarcinogenic effects of various groups of nanomaterials currently not classified as carcinogenic to humans.Preparing the review, information bases of biomedical literature were analysed: Scopus (307), PubMed (461), Web of Science (268), eLibrary.ru (190) were used. To obtain full-text documents, the electronic resources of PubMed Central (PMC), Science Direct, Research Gate, Sci-Hub and eLibrary.ru databases were used.

Identification of Potential Artefacts in In Vitro Measurement of Vanadium-Induced Reactive Oxygen Species (ROS) Production

We investigated vanadium, i.e., a redox-active heavy metal widely known for the generation of oxidative stress in cultured mammalian cells, to determine its ability to interfere with common oxidative stress-related bioassays in cell-free conditions. We first assessed the prooxidant abilities (H₂O₂ level, oxidation of DHR 123, and DCFH-DA dyes) and antioxidant capacity (ABTS, RP, OH, and DPPH methods) of popular mammalian cell culture media, i.e., Minimal Essential Medium (MEM), Dulbecco's Minimal Essential Medium (DMEM), Dulbecco's Minimal Essential Medium-F12 (DMEM/F12), and RPMI 1640. Out of the four media studied, DMEM has the highest prooxidant and antioxidant properties, which is associated with the highest concentration of prooxidant and antioxidant nutrients in its formulation. The studied vanadium compounds, vanadyl sulphate (VOSO₄), or sodium metavanadate (NaVO₃) (100, 500, and 1000 µM), either slightly increased or decreased the level of H₂O₂ in the studied culture media. However, these changes were in the range of a few micromoles, and they should rather not interfere with the cytotoxic effect of vanadium on cells. However, the tested vanadium compounds significantly stimulated the oxidation of DCFH-DA and DHR123 in a cell-independent manner. The type of the culture media and their pro-oxidant and antioxidant abilities did not affect the intensity of oxidation of these dyes by vanadium, whereas the vanadium compound type was important, as VOSO₄ stimulated DCFH-DA and DHR oxidation much more potently than NaVO₃. Such interactions of vanadium with these probes may artefactually contribute to the oxidation of these dyes by reactive oxygen species induced by vanadium in cells.

Gene Expression in Bronchial Epithelial Cell Responses to Vanadium Exposure

Vanadium exposure has the adverse effect on lung function in human, whereas the detailed mechanisms of vanadium exposure-induced pulmonary toxicity are limited. Hence, the present study aimed to investigate the hub genes and signaling pathways related to sodium metavanadate (SMV)-induced pulmonary toxicity. The transcript expression profile GSE36684 downloaded from Gene Expression Omnibus contained eight human bronchial epithelial cell (HBEC) samples including five SMV-treated and three control HBEC samples. Totally 455 differentially expressed genes (DEGs) were screened, especially 201 and 254 genes were up- and down-regulated in the HBECs treated with SMV. Gene ontology analysis suggested that the DEGs were mainly involved in signal transduction, the response to drug, cell proliferation, adhesion, and migration. Pathway analysis demonstrated that the DEGs were primarily participated in NF-κB, Wnt, MAPK, and PI3K-Akt signaling pathways. Moreover, the hub genes, including ITGA5, ITGB3, ITGA2, LAMC2, MMP2, and ITGA4, might contribute to SMV-induced pulmonary toxicity. Our study improves the understanding of the molecular mechanisms by which SMV induced the pulmonary toxicity.

Phytotoxicity of VO2 nanoparticles with different sizes to pea seedlings

Vanadium dioxide nanoparticles (VO2 NPs) have been massively produced due to their excellent metal-insulator transition characteristics for various applications. Pilot studies indicated the toxicity of VO2 NPs to bacteria and mammalian cells, but the environmental hazards of VO2 NPs to plants have been unrevealed to date. In this study, we reported the inhibitive effects of VO2 NPs to the growth and photosynthesis of pea seedlings. Laboratory synthesized monoclinic VO2 NPs (N-VO2), commercial nanosized VO2 NPs (S-VO2), and commercial microsized VO2 particles (M-VO2) were carefully characterized for environmental toxicity evaluations. VO2 particles were supplemented to culture medium for seed germination and seedling growth. All three VO2 samples did not affect the germination rates of pee seeds, while serious growth inhibition of pea seedlings was observed at 10 mg/L for S-VO2 and N-VO2, and 100 mg/L for M-VO2. VO2 particles had no impact on the chlorophyll contents, but the photosynthesis of leaf was significantly decreased following the consequence of N-VO2 > S-VO2 > M-VO2. The inhibition of photosynthesis was attributed to the damage of acceptor side of photosystem II by VO2 particles at high concentrations. Abundant bioaccumulations of vanadium in roots aroused oxidative damage and changed the root structure. Our results collectively indicated that the phytotoxicity of VO2 NPs was related to the concentration, size and crystalline degree.

Cytotoxicity Assessment of Nanoplastics and Plasticizers Exposure in In Vitro Lung Cell Culture Systems—A Systematic Review

Emerging contaminants such as nanoplastics (NPs), as well as manufacturing by-products such as plasticizers, have gained global attention and concern due to their limited biodegradability and their potential impact on human health, in particular the effects on respiratory tissue. In parallel, in vitro cell culture techniques are key to the assessment and characterization of toxic effects and cellular mechanisms in different types of tissues and should provide relevant information to understand the hazardous potential of these emergent contaminants. This systematic review presents the main results on the current knowledge of the effects of NPs and plasticizers on lung cells, as assessed with the use of in vitro cell culture techniques. From the selected studies (n = 10), following the PRISMA approach, it was observed that cell viability was the most frequently assessed endpoint and that most studies focused on epithelial cells and exposures to polystyrene (PS). It was observed that exposure to NPs or plasticizers induces cytotoxicity in a dose-dependent manner, regardless of the size of the NPs. Furthermore, there is evidence that the characteristics of NPs can affect the toxic response by promoting the association with other organic compounds. As such, further in vitro studies focusing on the combination of NPs with plasticizers will be essential for the understanding of mechanisms of NPs toxicity.

An Overview of the Importance of Transition-Metal Nanoparticles in Cancer Research

Several authorities have implied that nanotechnology has a significant future in the development of advanced cancer therapies. Nanotechnology makes it possible to simultaneously administer drug combinations and engage the immune system to fight cancer. Nanoparticles can locate metastases in different organs and deliver medications to them. Using them allows for the effective reduction of tumors with minimal toxicity to healthy tissue. Transition-metal nanoparticles, through Fenton-type or Haber-Weiss-type reactions, generate reactive oxygen species. Through oxidative stress, the particles induce cell death via different pathways. The main limitation of the particles is their toxicity. Certain factors can control toxicity, such as route of administration, size, aggregation state, surface functionalization, or oxidation state. In this review, we attempt to discuss the effects and toxicity of transition-metal nanoparticles.

UV Light-Activated GdYVO4:Eu3+ Nanoparticles Induce Reactive Oxygen Species Generation in Leukocytes Without Affecting Erythrocytes In Vitro

Nanoparticles (NPs) have been reported to be promising enhancement agents for radiation therapy. The aim of the study was to assess the cytotoxicity of UV non-treated and UV pretreated GdYVO₄:Eu³⁺ nanoparticles against erythrocytes and leukocytes by detecting eryptosis and reactive oxygen species (ROS) generation. Levels of intracellular ROS in erythrocytes and leukocytes using a ROS-sensitive dye 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA), as well as eryptosis rate utilizing annexin V staining, following direct exposure to UV-activated and nonactivated NPs were detected by flow cytometry. Blood cells were collected from 9 intact WAG rats. Neither the UV light-untreated GdYVO₄:Eu³⁺ NPs nor the treated ones promoted eryptosis and ROS generation in erythrocytes. Low concentrations of UV light-untreated NPs did not induce oxidative stress in leukocytes, evidenced by unaffected intracellular ROS levels. UV light treatment grants prooxidant properties to NPs, confirmed by NP-induced ROS overproduction in leukocytes. High concentrations of both UV light-treated and untreated NPs altered the redox state of leukocytes. UV light treatment imparts prooxidant properties to GdYVO₄:Eu³⁺ NPs, making them promising radiosensitizing agents in cancer radiation therapy.

Experimental Confirmation of Antimicrobial Effects of GdYVO4:Eu3+ Nanoparticles

Nanotechnology can be applied to design antibacterial agents to combat antibiotic resistance. The aim of the present study was to assess the antimicrobial effects and cytotoxicity of GdYVO₄:Eu³⁺ nanoparticles (NPs). Biofilm inhibition activity, antimicrobial activity, bacterial viability inhibition and DNA cleavage activity of GdYVO₄:Eu³⁺ NPs were studied. In addition, the impact of GdYVO₄:Eu³⁺ NPs on the mitochondrial membrane potential (ΔΨ_M) of host immune cells and, hence, their apoptosis was analyzed by JC-1 staining using flow cytometry. GdYVO₄:Eu³⁺ NPs demonstrated good antimicrobial, cell viability inhibition and DNA cleavage activities. In addition, GdYVO₄:Eu³⁺ NPs showed good biofilm inhibition activity against S. aureus and P. aeruginosa and inhibition percentages were 89.15% and 79.54%, respectively. However, GdYVO₄:Eu³⁺ NPs promoted mitochondrial depolarization and apoptosis of leukocytes at high concentrations. GdYVO₄:Eu³⁺ nanoparticles are promising antibacterial agents. However, more efforts should be exerted to ensure their safety.

Co-Exposure of Nanopolystyrene and Other Environmental Contaminants-Their Toxic Effects on the Survival and Reproduction of Enchytraeus crypticus

Plastics in all shapes and sizes have become widespread across ecosystems due to intense anthropogenic use. As such, they can interact with other contaminants that accumulate in the terrestrial environment, such as pharmaceuticals, metals or nanomaterials (NMs). These interactions can potentiate combined toxic effects in the exposed soil organisms, with hazardous long-term consequences to the full ecosystem. In the present study, a terrestrial model species, Enchytraeus crypticus (oligochaeta), was exposed through contaminated soil with nanopolystyrene (representative of nanoplastics (NPls)), alone and in combination with diphenhydramine (DPH, representative of pharmaceuticals), silver nitrate (AgNO₃, representative of metals) and vanadium nanoparticles (VNPs, representative of NMs). AgNO₃ and VNPs decreased E. crypticus reproduction at 50 mg/kg, regardless of the presence of NPls. Moreover, at the same concentration, both single and combined VNP exposures decreased the E. crypticus survival. On the other hand, DPH and NPls individually caused no effect on organisms' survival and reproduction. However, the combination of DPH (10 and 50 mg/kg) with 300 mg NPls/kg induced a decrease in reproduction, showing a relevant interaction between the two contaminants (synergism). Our findings indicate that the NPls can play a role as vectors for other contaminants and can potentiate the effects of pharmaceuticals, such as DPH, even at low and sub-lethal concentrations, highlighting the negative impact of mixtures of contaminants (including NPls) on soil systems.

The Effect of Vanadium Inhalation on the Tumor Progression of Urethane-Induced Lung Adenomas in a Mice Model

Lung cancer has the highest death rates. Aerosol drug delivery has been used for other lung diseases. The use of inhaled vanadium (V) as an option for lung cancer treatment is explored. Four groups of mice were studied: (1) Saline inhalation alone, (2) Single intraperitoneal (i.p.) dose of urethane, (3) V nebulization twice a week (Wk) for 8 Wk, and (4) A single dose of urethane and V nebulization for 8 Wk. Mice were sacrificed at the end of the experiment. Number and size of tumors, PCNA (proliferating cell nuclear antigen) and TUNEL (terminal deoxynucleotidyl tranferase dUTP nick-end labeling) immunohistochemistry were evaluated and compared within groups. Results: The size and number of tumors decreased in mice exposed to V-urethane and the TUNEL increased in this group; differences in the PCNA were not observed. Conclusions: Aerosol V delivery increased apoptosis and possibly the growth arrest of the tumors with no respiratory clinical changes in the mice.

Effects of VO2 nanoparticles on human liver HepG2 cells: Cytotoxicity, genotoxicity, and glucose and lipid metabolism disorders

The rapid development of smart materials stimulates the production of vanadium dioxide (VO₂) nanomaterials. This significantly increases the population exposure to VO₂ nanomaterials via different pathways, and thus urges us to pay more attentions to their biosafety. Liver is the primary accumulation organ of nanomaterials in vivo, but the knowledge of effects of VO₂ nanomaterials on the liver is extremely lacking. In this work, we comprehensively evaluated the effects of a commercial VO₂ nanoparticle, S-VO₂, in a liver cell line HepG2 to illuminate the potential hepatic toxicity of VO₂ nanomaterials. The results indicated that S-VO₂ was cytotoxic and genotoxic to HepG2 cells, mainly by inhibiting the cell proliferation. Apoptosis was observed at higher dose of S-VO₂, while DNA damage was detected at all tested concentrations. S-VO₂ particles were internalized by HepG2 cells and kept almost intact inside cells. Both the particle and dissolved species of S-VO₂ contributed to the observed toxicities. They induced the overproduction of ROS, and then caused the mitochondrial dysfunction, ATP synthesis interruption, and DNA damages, consequently arrested the cell cycle in G2/M phase and inhibited the proliferation of HepG2 cells. The S-VO₂ exposure also resulted in the upregulations of glucose uptake and lipid content in HepG2 cells, which were attributed to the ROS production and autophagy flux block, respectively. Our findings offer valuable insights into the liver toxicity of VO₂ nanomaterials, benefiting their safely practical applications.

Environmental Hazards of Boron and Vanadium Nanoparticles in the Terrestrial Ecosystem-A Case Study with Enchytraeus crypticus

From the start of the 21st century, nanoecotoxicological research has been growing in fast steps due to the need to evaluate the safety of the increasing use of engineered nanomaterials. Boron (B) and vanadium (V) nanoparticles (NPs) generated by anthropogenic activities are subsequently released in the environment; therefore, organisms can be continuously exposed to these NPs for short or long periods. However, the short and long-term effects of BNPs and VNPs on soil organisms are unknown. This work aimed to recognize and describe their potential toxicological effects on the model species Enchytraeus crypticus, assessing survival and reproduction, through a longer-term exposure (56 days (d)-OECD test extension of 28 d), and avoidance behavior, through a short-term exposure (48 hours (h)). After 28 d, BNPs did not induce a significant effect on E. crypticus survival, whereas they decreased the organisms' reproduction at 500 mg/kg. From 10 to 500 mg/kg, VNPs decreased the E. crypticus survival and/or reproduction. After 56 d, 100 to 500 mg/kg BNPs and 50 to 500 mg/kg VNPs, decreased the reproduction output of E. crypticus. The estimated Effect Concentrations (EC_x) based on reproduction, for BNPs, were lower at 56 d compared with 28 d; for VNPs, an opposite pattern was found: EC_x 28 d < EC_x 56 d. BNPs did not induce an avoidance behavior, but organisms avoided the soil contaminated with 10 mg VNPs/kg. The tested NPs showed different E. crypticus apical effects at 28 d from the ones detected at 56 d, dependent on the type of NPs (B vs. V). In general, VNPs showed to be more toxic than BNPs. However, the effects of VNPs were alleviated during the time of exposure, contrarily to BNPs (which became more toxic with extended duration). The present study adds important information about NPs toxicity with ecological significance (at the population level). Including long-term effects, the obtained results contributes to the improvement of NPs risk assessment.

Cytotoxicity and genotoxicity of low-dose vanadium dioxide nanoparticles to lung cells following long-term exposure

Vanadium dioxide nanoparticles (VO₂ NPs) have been massively produced and widely applied due to their excellent metal-insulator transition property, making it extremely urgent to evaluate their safety, especially for low-dose long-term respiratory occupational exposure. Here, we report a comprehensive cytotoxicity and genotoxicity study on VO₂ NPs to lung cell lines A549 and BEAS-2B following a long-term exposure. A commercial VO₂ NP, S-VO₂, was used to treat BEAS-2B (0.15-0.6 μg/mL) and A549 (0.3-1.2 μg/mL) cells for four exposure cycles, and each exposure cycle lasted for 4 consecutive days; then various bioassays were performed after each cycle. Significant proliferation inhibition was observed in both cell lines after long-term exposure of S-VO₂ at low doses that did not cause apparent acute cytotoxicity; however, the genotoxicity of S-VO₂, characterized by DNA damage and micronuclei, was only observed in A549 cells. These adverse effects of S-VO₂ were exposure time-, dose- and cell-dependent, and closely related to the solubility of S-VO₂. The oxidative stress in cells, i.e., enhanced reactive oxygen species (ROS) generation and suppressed reduced glutathione, was the main toxicity mechanism of S-VO₂. The ROS-associated mitochondrial damage and DNA damage led to the genotoxicity, and cell proliferation retard, resulting in the cellular viability loss. Our results highlight the importance and urgent necessity of the investigation on the long-term toxicity of VO₂ NPs.

Current understanding of nanoparticle toxicity mechanisms and interactions with biological systems

Nanotechnology is an emerging science involving the manipulation of matter on the nanometer scale.

Microwave-Assisted Synthesis and Characterization of Solar-Light-Active Copper–Vanadium Oxide: Evaluation of Antialgal and Dye Degradation Activity

In this work, solar-light-active copper–vanadium oxide (Cu-VO) was synthesized by a simple microwave method and characterized by FESEM, EDS, XRD, XPS, UV–Vis/near-infrared (NIR), and FT-IR spectroscopy. Antialgal and dye degradation activities of Cu-VO were investigated against Microcystis aeruginosa and methylene blue dye (MB), respectively. The mechanism of action of Cu-VO was examined regarding the production of hydroxyl radical (·OH) in the medium and intracellular reactive oxygen species (ROS) in M. aeruginosa. FESEM and XRD analyses of Cu-VO disclosed the formation of monoclinic crystals with an average diameter of 132 nm. EDX and XPS analyses showed the presence of Cu, V, and O atoms on the surface of Cu-VO. Furthermore, FT-IR analysis of Cu-VO exposed the presence of tetrahedral VO4 and octahedral CuO6. Cu-VO effectively reduced the algal growth and degraded methylene blue under solar light. A total of 4 mg/L of Cu-VO was found to be effective for antialgal activity. Cu-VO degraded 93% of MB. The investigation of the mechanism of action of Cu-VO showed that ·OH mediated antialgal and dye degradation of M. aeruginosa and MB. Cu-VO also triggered the production of intracellular ROS in M. aeruginosa, leading to cell death. Thus, Cu-VO could be an effective catalyst for wastewater treatment.

Reactive Oxygen Species-Related Nanoparticle Toxicity in the Biomedical Field

The unique physicochemical characteristics of nanoparticles have recently gained increasing attention in a diverse set of applications, particularly in the biomedical field. However, concerns about the potential toxicological effects of nanoparticles remain, as they have a higher tendency to generate excessive amounts of reactive oxygen species (ROS). Due to the strong oxidation potential, the excess ROS induced by nanoparticles can result in the damage of biomolecules and organelle structures and lead to protein oxidative carbonylation, lipid peroxidation, DNA/RNA breakage, and membrane structure destruction, which further cause necrosis, apoptosis, or even mutagenesis. This review aims to give a summary of the mechanisms and responsible for ROS generation by nanoparticles at the cellular level and provide insights into the mechanics of ROS-mediated biotoxicity. We summarize the literature on nanoparticle toxicity and suggest strategies to optimize nanoparticles for biomedical applications.