Cytotoxicity investigations of biogenic tellurium nanorods towards PC12 cell line (original) (raw)
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Acute and subacute toxicities of biogenic tellurium nanorods in mice
Regulatory Toxicology and Pharmacology, 2017
The current study was performed to evaluate the acute and subacute toxicities of biogenic tellurium nanorods (Te NRs). The Te NRs were prepared using Pseudomonas pseudoalcaligenes strain Te in a culture medium containing K 2 TeO 3 (1 mM) and their physiochemical properties were investigated using TEM, EDX and XRD. The median lethal dose (LD 50) of Te NRs and potassium tellurite (K 2 TeO 3) were determined in mice and the subacute toxicity was also evaluated. The experimental design involved certain general toxicological, haematological, serum and histopathological investigations. The TEM and XRD analyses showed that the biogenic nanoparticles were rod-shaped and hexagonal. The toxicological evaluation showed that the LD 50 values of Te NRs and K 2 TeO 3 were 60 and 12.5 mg/kg, respectively. Higher doses of Te NRs (6 mg/kg) and K 2 TeO 3 (1.25 mg/kg) were accompanied by signs of toxicity, including lower body weight, elevation in MDA and depletion in GSH content, SOD and CAT activity, and changes in biochemistry parameters. No obvious histopathological changes were observed in the treatment with Te NRs. In conclusion, the biogenic Te NRs were less toxic as compared to K 2 TeO 3 , and the no-observed-adverse-effect level (NOAEL) dose of Te NRs in 14 days subacute toxicity study was lower than 1.2 mg/kg.
Iranian Journal of Biotechnology
Background: Recent theranostic (therapeutic or diagnostic) applications of tellurium nanoparticles have attracted a great interest for development of diff erent methods for synthesis of this valuable nanostructure, especially via biological resources. Objectives: In the present study, the antimicrobial and antioxidant eff ects of the tellurium nanorods (Te NRs) biosynthesized by a bacterial strain Pseudomonas pseudoalcaligenes strain Te were evaluated. Materials and Methods: The antimicrobial eff ect of Te NRs and potassium tellurite against diff erent bacterial and fungal pathogens was assessed by microdilution method. Furthermore, the disk diff usion method was used to evaluate the antibacterial eff ect of the biogenic Te NRs and potassium tellurite against methicillin-resistant Staphylococcus aureus, alone or in combination with various antibiotics. Also, the biogenic Te NRs were investigated for antioxidant activity using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and reducing power assay. Results: Transmission electron micrograph (TEM) of the purifi ed Te NRs showed individual and rod-shaped nanostructure (~22 nm diameter by 185 nm in length). Based on the data obtained from both microdilution and disk diff usion method the K 2 TeO 3 exhibited a higher antibacterial and antifungal activity compared to the Te NRs. The measured IC 50 for the biogenic Te NRs (i.e. DPPH radical scavenging activity) was found to be 24.9 μg.mL-1 , while, K 2 TeO 3 has represented only 17.6 ± 0.8 % DPPH radical scavenging eff ect at the concentration of 160 μg.mL-1. The reducing power assay revealed a higher electron-donating activity for Te NRs compared to K 2 TeO 3. Conclusions: Based on the data obtained from both microdilution and disk diff usion method the K 2 TeO 3 exhibited a higher antimicrobial and antifungal activity than Te NRs. Te NRs didn't show the antibacterial eff ect against the tested bacterial strain: MRSA and showed an inhibitory eff ect and antibacterial activity of the eff ective antibiotics. However, more studies should be performed to explore the action mechanism of the produced biogenic Te NRs.
A comparative study of tellurite toxicity in normal and cancer cells
Molecular & Cellular Toxicology, 2012
Data regarding tellurium (Te) toxicity are scarce but metabolic studies in bacteria highlight a major role of reactive oxygen species (ROS). Concentration-and time-dependent cell death has been reported in cancer cells exposed to inorganic tellurite. However, the potential in vitro effect that tellurite could generates in non-transformed human cells is still unknown. Therefore, we have studied the toxicity of inorganic tellurite (K 2 TeO 3 ) in both freshly isolated peripheral blood leukocytes and in human chronic myeloid leukemia cells (K562 cells). Interestingly, we observed higher increases of ROS in leukocytes after treatment with tellurite, as compared to K562 cells. Given the high reactivity of tellurite with glutathione (GSH), a mechanism that leads to ROS formation (and mainly superoxide anion), we postulate that such a difference between cancer and normal cells is likely due to the higher GSH contents found in leukocytes versus leukemia cells. Taken together, our data point out the major differences that can be observed between cancer and corresponding normal cells in studies looking for in vitro toxicity.
Journal of Nanoparticle Research, 2018
Antibiotic resistance is a predicament that affects more than 2 million people worldwide each year. Through the over-prescription and extensive use of antibiotics, bacteria have generated resistance to many common antibiotic treatments. A promising approach to target antibiotic-resistant bacteria is the use of metallic nanoparticles. In this work, an environmentally safe synthesis of tellurium nanoparticles was explored. Rodshaped tellurium nanoparticles coated with polyvinylpyrrolidone (PVP) were prepared using a facile hydrothermal reduction reaction. Transmission electron microscopy (TEM) images were used to characterize the size and morphology of the nanoparticles and showed a narrow size distribution. In addition, energy dispersive X-ray spectroscopy (EDS) was performed to verify the chemical composition of the nanoparticles. Antibacterial assays determined that treatment with nanoparticles at concentrations of 25 to 100 μg/mL induced a decay in the growth of both Gram-negative and Gram-positive bacteria-both antibiotic-resistant and non-antibioticresistance strains. To determine the effects of the nanoparticles on off-target cells, cytotoxicity assays were performed using human dermal fibroblasts (HDF) and melanoma (skin cancer) cells for durations of 24 and 48 h. Treatment with nanoparticles at concentrations between 10 and 100 μg/mL showed no significant cytotoxicity towards HDF cells. Contrarily, in melanoma cells, a cytotoxic effect was observed at the same concentrations. This suggests that the nanoparticles possess both anticancer properties towards melanoma cells and antibacterial effects without being toxic to healthy cells. These properties show that, for the first time, PVPcoated tellurium nanorods can be exploited for the treatment of antibiotic-resistant bacterial infections. These nanorods should be further explored for numerous antibacterial and anticancer applications.
Oxidative stress mediated cytotoxicity of tellurite in MDA-MB-231 breast cancer cells
Journal of King Saud University - Science, 2019
Among different metallic compounds, tellurium (Te) was investigated as having anticancer properties. In the current investigation, MDA-MB-231 breast cancer cell line was cultured with or without tellurite to measure live cells by crystal violet staining. TrxR systems can be acted as a leader for anticancer therapy by eliminating cancerous cells through inhibition of TrxR and glutathione reductase (GR). Oxidative stress, generated in higher concentration in tellurite exposed cells, leads to lower the cell reduced environment such as reduced glutathione GSH) and non-protein thiol. Tellurite exposed cells underwent both type of cell death via necrosis and apoptosis. The lateral was slowed as tellurite concentration increased which was measured by caspase-3 activity, thus this finding would be very useful for determination of type and extent of cell death occurred by tellurite via biochemical and morphological ways. By elucidating the role of tellurite in inducing cell death in carcinoma cells by increased production of reactive oxygen species, this method could be employed for the treatment of carcinoma cells.
Toxicology - New Aspects to This Scientific Conundrum, 2016
Nanotoxicology represents a new and growing research area in toxicology. It deals with the assessment of the toxicological properties of nanoparticles (NPs) with the intention of determining whether (and to what extent) they pose an environmental or societal threat. Inherent properties of NPs (including size, shape, surface area, surface charge, crystal structure, coating, and solubility/dissolution) as well as environmental factors (such as temperature, pH, ionic strength, salinity, and organic matter) collectively influence NP behavior, fate and transport, and ultimately toxicity. The mechanisms underlying the toxicity of nanomaterials (NMs) have recently been studied extensively. Reactive oxygen species (ROS) toxicity represents one such mechanism. An overproduction of ROS induces oxidative stress, resulting in inability of the cells to maintain normal physiological redoxregulated functions. In the context of this book, this chapter includes topics pertaining to chemical and physical properties of NMs and characterization for proper toxicological evaluation, exposure, and environmental fate and transport, and ecological and genotoxic effects. This chapter reviews the available research pertaining specifically to NMs in the aquatic environment (in plants, aquatic invertebrates, and fish) and their use in biomarker studies.
Nano Letters, 2006
Nanomaterial properties differ from those bulk materials of the same composition, allowing them to execute novel activities. A possible downside of these capabilities is harmful interactions with biological systems, with the potential to generate toxicity. An approach to assess the safety of nanomaterials is urgently required. We compared the cellular effects of ambient ultrafine particles with manufactured titanium dioxide (TiO 2 ), carbon black, fullerol, and polystyrene (PS) nanoparticles (NPs). The study was conducted in a phagocytic cell line (RAW 264.7) that is representative of a lung target for NPs. Physicochemical characterization of the NPs showed a dramatic change in their state of aggregation, dispersibility, and charge during transfer from a buffered aqueous solution to cell culture medium. Particles differed with respect to cellular uptake, subcellular localization, and ability to catalyze the production of reactive oxygen species (ROS) under biotic and abiotic conditions. Spontaneous ROS production was compared by using an ROS quencher (furfuryl alcohol) as well as an NADPH peroxidase bioelectrode platform. Among the particles tested, ambient ultrafine particles (UFPs) and cationic PS nanospheres were capable of inducing cellular ROS production, GSH depletion, and toxic oxidative stress. This toxicity involves mitochondrial injury through increased calcium uptake and structural organellar damage. Although active under abiotic conditions, TiO 2 and fullerol did not induce toxic oxidative stress. While increased TNF-r production could be seen to accompany UFP-induced oxidant injury, cationic PS nanospheres induced mitochondrial damage and cell death without inflammation. In summary, we demonstrate that ROS generation and oxidative stress are a valid test paradigm to compare NP toxicity. Although not all materials have electronic configurations or surface properties to allow spontaneous ROS generation, particle interactions with cellular components are capable of generating oxidative stress.
Nanotoxicology and in vitro studies: The need of the hour
Toxicology and Applied Pharmacology, 2012
In vitro cytotoxicity Bio-distribution of nanoparticles Genotoxicity of nanoparticles Molecular determinants of nanotoxicology Nanotechnology is considered as one of the key technologies of the 21st century and promises revolution in our world. Objects at nano scale, take on novel properties and functions that differ markedly from those seen in the corresponding bulk counterpart primarily because of their small size and large surface area. Studies have revealed that the same properties that make nanoparticles so unique could also be responsible for their potential toxicity. Nanotechnology is rapidly advancing, with more than 1000 nanoproducts already on the market. Considering the fact that intended as well as unintended exposure to nanomaterials is increasing and presently no clear regulatory guideline(s) on the testing/evaluation of nanoparticulate materials are available, the in vitro toxicological studies become extremely relevant and important. This review presents a summary of nanotoxicology and a concise account of the in vitro toxicity data on nanomaterials. For nanomaterials to move into the applications arena, it is important that nanotoxicology research uncovers and understands how these multiple factors influence their toxicity so that the ensuing undesirable effects can be avoided.
Nanomaterials Toxicity and Cell Death Modalities
Journal of Drug Delivery, 2012
In the last decade, the nanotechnology advancement has developed a plethora of novel and intriguing nanomaterial application in many sectors, including research and medicine. However, many risks have been highlighted in their use, particularly related to their unexpected toxicityin vitroandin vivoexperimental models. This paper proposes an overview concerning the cell death modalities induced by the major nanomaterials.