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Background/Aims: The development of new nanomaterials has been growing in recent decades to bring benefits in several areas, especially carbon-based nanoparticles, which have unique physical-chemical properties and allow to take on several applications. Consequently, the use of new nanomaterials without previous toxicological studies raises concern about possible harmful health effects. The aim of this study was to investigate the cytotoxic profile of a new multi-walled carbon nanotube (MWCNT) functionalized with tetraethylenepentamine called OCNT-TEPA using in vitro assays in murine macrophage cells linage J774 A.1. Methods: OCNT-TEPA was characterized by transmission electron microscopy (TEM) and high resolution TEM (HR-TEM), scanning electron microscopy (SEM), zeta potential and dynamic light scattering (DLS), and its cytotoxic effects were evaluated at 24 and 48 hours by cell viability assays (MTT and NR), morphology and cell recovery (optic microscopy and clonogenic assay), formation of reactive oxygen (ROS) and nitric oxide (NO) species, inflammatory profile (IL-6 and TNF cytokines), mitochondrial membrane potential analysis (MMP), activation of the caspase 3 pathway and cell death (flow cytometry). Results: The data showed a significant decrease in cell viability, increased production of ROS and NO, alteration of mitochondrial membrane potential, increased levels of inflammatory cytokines, alteration of cell morphology, activation of the Caspase 3 pathway and consequently cell death, in the highest concentrations of OCNTTEPA tested in the periods of 24 and 48 hours. Conclusion: The analyses showed that OCNTTEPA has a dose-dependent cytotoxic profile, which may be harmful to murine macrophages (J774 A.1) and may represent a health risk. [ABSTRACT FROM AUTHOR]

The extensive use of titanium dioxide nanoparticles (TiO2 NPs) in cosmetics, food, personal care products, and industries brought concerns about their possible harmful effects. Nowadays it has become important to assess TiO2 NPs toxic effects as a way to understand their primary risks. In the cellular environment, after cell uptake, TiO2 NPs were described to induce reactive oxygen species (ROS) production, unbalance oxidative state, and activate apoptosis in several cell lines. Therefore, we aimed to evaluate the cytotoxicity and genotoxicity of a new TiO2 NP surface-functionalized with sodium carboxylic ligands in a murine fibroblast cell line (LA-9). TEM and DLS analyses were performed to define nanoparticle physicochemical characteristics. We evaluated the metabolic activity and LDH released after 24 h exposition to determine cytotoxic effects. Also, we evaluated DNA damage, intracellular reactive oxygen species (ROS) production, and apoptosis induction after 24 h exposure. The TiO2 NP impaired the cell membrane integrity at 1000 μg/mL, induced intracellular ROS production and late apoptosis at 24 h. The genotoxic effects were observed at all conditions tested at 24 h. Indeed, in fibroblasts exposed at 100 μg/mL was observed early apoptosis cells. The intracellular ROS content was increased in a dose-dependent manner. Thus, short-term exposure to TiO2 NP promoted cytotoxicity, genotoxicity and activated apoptosis pathways based on the potential role of oxygen species in the fibroblasts cell line. [ABSTRACT FROM AUTHOR]

Background/Aims: A new type of nanoparticle, called NP CB-EDA (Black Carbon modified with ethylenediamine), is commonly used in the oil industry. In the literature, few studies are found in biological models, making NP-EDA potential cytotoxicity in organisms unclear. As its large surface area is capable of interacting with the biological system, that interaction could lead to factors harmful to health. The objective of this study was to investigate the cytotoxic effect of NP CB-EDA on fibroblasts LA-9 at 24 and 48 hours, at different concentrations of the nanoparticle (1, 50, 250, 500 and 1000 µg/ml). Methods: NP CB-EDA was characterized by TEM microscopy and its effect on cell viability (MTT method), cell morphology (optical microscopy), cell membrane (lactate dehydrogenase release - LDH), oxidative stress pathways (species levels reactive oxygen, ROS and nitrogen, NOS) and apoptosis/necrosis (flow cytometry) were evaluated. Results: The results show that NP CB-EDA at concentrations of 500 and 1000 µg/ ml form clusters. The nanoparticle can be absorbed by cells decreasing cell viability. There was damage to the cell membrane of fibroblasts LA 9, an increase in the production of ROS, NOS and pro-inflammatory interleukins TNF-α and IL-6; it was also observed an increase in % of cells in the state of apoptosis in the two periods analyzed, being this response more significant in 24 hours, and concentrations of 250, 500 and 1000 µg/ml presenting higher cytotoxicity. Conclusion: The data suggest that NP CB-EDA in fibroblasts LA9 presents cytotoxic potential, which is associated with oxidative stress and apoptosis. [ABSTRACT FROM AUTHOR]