Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.145
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Top Curr Chem (Cham) ; 378(1): 15, 2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31938922

RESUMO

Nowadays, biomaterials have become a crucial element in numerous biomedical, preclinical, and clinical applications. The use of nanoparticles entails a great potential in these fields mainly because of the high ratio of surface atoms that modify the physicochemical properties and increases the chemical reactivity. Among them, carbon nanotubes (CNTs) have emerged as a powerful tool to improve biomedical approaches in the management of numerous diseases. CNTs have an excellent ability to penetrate cell membranes, and the sp2 hybridization of all carbons enables their functionalization with almost every biomolecule or compound, allowing them to target cells and deliver drugs under the appropriate environmental stimuli. Besides, in the new promising field of artificial biomaterial generation, nanotubes are studied as the load in nanocomposite materials, improving their mechanical and electrical properties, or even for direct use as scaffolds in body tissue manufacturing. Nevertheless, despite their beneficial contributions, some major concerns need to be solved to boost the clinical development of CNTs, including poor solubility in water, low biodegradability and dispersivity, and toxicity problems associated with CNTs' interaction with biomolecules in tissues and organs, including the possible effects in the proteome and genome. This review performs a wide literature analysis to present the main and latest advances in the optimal design and characterization of carbon nanotubes with biomedical applications, and their capacities in different areas of preclinical research.


Assuntos
Nanomedicina/métodos , Nanotecnologia/métodos , Nanotubos de Carbono/análise , Animais , Humanos , Modelos Moleculares , Nanotubos de Carbono/toxicidade , Nanotubos de Carbono/ultraestrutura
2.
Ecotoxicol Environ Saf ; 187: 109825, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31677570

RESUMO

In recent years, the release of nanomaterials pollutants to water bodies, to a great extent, attributed to anthropogenic activities. Their impacts on aquatic organisms as well as nanomaterial monitoring and bioremediation using organism have drawn much attentions. However, studies on relationship of nano-contaminants and aquatic organisms are very scarce. Our results showed that titanium dioxide nanoparticles (TiO2-NPs) and Multi-walled carbon nanotubes (MWCNTs) caused an obvious cell decreases on the whole, but a significant increase at 48 h TiO2-NPs exposure, indicating a resistant mechanism in ciliates for nano-toxic. Besides, MWCNTs was more toxic to Pseudocohnilembus persalinus than that of TiO2-NPs in terms of EC50 value. It is firstly found that P. persalinus ingested and released TiO2-NPs through cytostome and cytoproct, which might be the reason that TiO2-NPs less toxic than MWCNTs. The significantly increased superoxide dismutase (SOD) and glutathione S-transferase (GST) enzyme activities and expression levels were evaluated by reactive oxygen species ROS generation, which demonstrated that P. persalinus antioxidant defense enzyme played roles on nano-toxic resistant in ciliates. Moreover, the integrated biomarker response (IBR) was also determined, which demonstrated that MWCNTs had comparatively higher values than those of TiO2-NPs after higher concentration exposure to ciliates. In addition, it was confirmed by the present work that sod, gst and cat played different roles on immunity, and the sensitivity of cat gene expression to these two nanomaterials exposure was dissimilar. Damages of shrunk as well as losses of cilia on the cell surface caused by TiO2-NPs and MWCNTs exposure in P. persalinus using SEM revealed possible physical hazards of aggregated nanomaterials. Our findings will be helpful to understand the effect mechanisms of NPs on ciliates, and also demonstrated the possibility of P. persalinus as bio-indicator of nanomaterials in aquatic and potentials on bioremediation.


Assuntos
Nanopartículas Metálicas , Nanotubos de Carbono , Oligoimenóforos/fisiologia , Titânio/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Antioxidantes/metabolismo , Biodegradação Ambiental , Biomarcadores Ambientais , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Nanotubos de Carbono/toxicidade , Oligoimenóforos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade
3.
Environ Toxicol ; 35(1): 87-96, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31515868

RESUMO

Increasing consumption of metal-oxide nanoparticles (NPs) and carbon-based nanomaterials has caused significant concern about their potential hazards in aquatic environments. The release of NPs into aquatic environments could result in adsorption of NPs on microorganisms. While metal-oxide NP-conjugated carbon-based nanohybrids (NHs) may exhibit enhanced toxicity toward microorganisms due to their large surface area and the generation of reactive oxygen species (ROS), there is a lack of information regarding the ecotoxicological effects of NHs on marine diatom algae, which are an indicator of marine pollution. Moreover, there is scant information on toxicity mechanisms of NHs on aquatic organisms. In this study, four NHs (ie, ZnO-conjugated graphene oxide [GO], ZnO-conjugated carbon nanotubes [CNTs], TiO2 -conjugated GO, and TiO2 -conjugated CNT) that were synthesized by a hydrothermal method were investigated for their toxicity effects on a Thalassiosira pseudonana marine diatom. The in vitro cellular viability and ROS formation employed at the concentration ranges of 50 and 100 mg/L of NHs over 72 hours revealed that ZnO-GO had the most negative effect on T. pseudonana. The primary mechanism identified was the generation of ROS and GO-induced dispersion that caused electrostatic repulsion, preventing aggregation, and an increase in surface areas of NHs. In contrast to GO-induced dispersion, large aggregates were observed in ZnO/TiO2 -conjugated CNT-based NHs. The scanning electron microscopy images suggest that NHs covered algae cells and interacted with them (shading effects); this reduced light availability for photosynthesis. Detailed in vitro toxicity effects and mechanisms that cause high adverse acute toxicity on T. pseudonana were unveiled; this implied concerns about potential hazards of these mechanisms in aquatic ecosystems.


Assuntos
Diatomáceas/efeitos dos fármacos , Grafite/toxicidade , Nanotubos de Carbono/toxicidade , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Óxido de Zinco/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Organismos Aquáticos/crescimento & desenvolvimento , Sobrevivência Celular/efeitos dos fármacos , Diatomáceas/crescimento & desenvolvimento , Ecossistema , Grafite/química , Nanotubos de Carbono/química , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Propriedades de Superfície , Titânio/química , Poluentes Químicos da Água/química , Óxido de Zinco/química
4.
Biophys Chem ; 256: 106268, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31707064

RESUMO

Carbon nanotubes (CNTs) are extensively used in the area of biotechnology and biomedicine, and the binding of proteins to CNTs plays an important role in the potential toxicity of nanomaterials. Rutin is a glycoside of the bioactive quercetin with various health-improving effects due to its antioxidant ability. Demonstration of the interaction between serum albumin and bioactive components is important to design effective carriers for the suppression of CNTs' toxicity. In this study, bindings of bovine serum albumin (BSA) to single-walled CNTs and/or rutin were investigated by fluorescence and molecular docking techniques. The fluorescence of BSA was significantly quenched by both CNTs and rutin in static mode, which was confirmed by the Stern-Volmer calculations. Although rutin showed higher affinity to protein than CNTs, the interactions of both components with BSA did mainly locate within subdomain IIA (site I). BSA-diligand complexes were successfully formed after the simultaneous addition of CNTs and rutin. Bioactive rutin in the BSA-diligand complex still kept strong free radical scavenging activity compared to free rutin or BSA-monoligand complex. Consistently, the cytotoxicity of CNTs and reactive oxygen species formation in endothelial cells was reduced in the BSA-diligand complexes relative to those of BSA-CNTs corona or CNTs alone, where the co-presence of rutin played an important role. These findings suggest the possibility and advantage of designing BSA-based carriers for the suppression of CNTs' toxicity in their biomedical applications.


Assuntos
Nanotubos de Carbono/química , Rutina/química , Soroalbumina Bovina/química , Animais , Antioxidantes/química , Sítios de Ligação , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana , Humanos , Simulação de Acoplamento Molecular , Nanotubos de Carbono/toxicidade , Estrutura Terciária de Proteína , Rutina/metabolismo , Soroalbumina Bovina/metabolismo
5.
Chemosphere ; 240: 124931, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31561161

RESUMO

Carbon nanotubes (CNTs) have been widely used in many scientific fields including plant sciences due to their unique physical and chemical properties. However, little is known about the toxic effects of CNTs combined with cadmium (Cd) on wheat. The aim of this study was to investigate the effects of single-walled carbon nanotubes (SW) and multi-walled carbon nanotubes (MW) on the phytotoxicity of Cd in wheat. A hydroponic culture was carried out to study wheat seedling growth in six treatments, namely Cd only (Cd); MW only (MW); SW only (SW); SW combined with Cd (SWCd); MW combined with Cd (MWCd); and a control (neither Cd nor carbon nanotubes). Compared with the Cd, SW/MW alone, CNTsCd treatments induced a reduction in total root length, root surface area, average root diameter, number of root hairs, and the dry weight of shoots and roots, which indicated that wheat growth and development was significantly inhibited. In addition, an obvious decrease in tubulins in the roots was observed. However, SW/MWCd induced a significant increase in glutathione S-transferase and cyochrome P450 in the shoots and roots, which indicated that the defense ability of wheat seedlings had improved, thus alleviating Cd stress. Moreover, Cd content increased significantly in shoot and root tissues with an increase in SW/MW content, compared to the Cd treatment. According to the transmission electron microscopy, CNTs alone destroyed the cell structure, and this devastating phenomenon was deepened after combining Cd and CNTs due to CNTs carrying Cd to attack cells. Compared with MW, SW had a greater effect on wheat seedlings. To conclude, CNTs increase the toxicity of Cd to wheat seedlings. These results are significant as they evaluate indirect phytotoxicity of CNTs for adsorbing heavy metals and plant growth regulators. In view of the widespread exposure of agricultural crops to Cd, the nanotoxicity of CNTs should be seriously considered in relation to food security in the future.


Assuntos
Cádmio/toxicidade , Nanotubos de Carbono/toxicidade , Raízes de Plantas/fisiologia , Plântula/crescimento & desenvolvimento , Triticum/crescimento & desenvolvimento , Transporte Biológico , Sistema Enzimático do Citocromo P-450/metabolismo , Glutationa Transferase/metabolismo , Hidroponia , Microscopia Eletrônica de Transmissão , Reguladores de Crescimento de Planta/farmacologia
6.
Bioelectrochemistry ; 131: 107346, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31706115

RESUMO

Carbon nanotubes (CNTs) have been reported to promote symbiotic metabolism in bacteria by accelerating interspecies electron transfer. However, this phenomenon has not been investigated or proven in a cocultures system. In this study, multi-walled CNTs (MWCNTs) were added into Geobacter cocultures systems with the ability of direct interspecies electron transfer (DIET). Results showed that addition of MWCNTs accelerated the metabolic rate of the cocultures. Succinate production rate in a test with 1.0gL-1 MWCNTs was 1.12mM d-1, 1.67 times higher than without MWCNTs. However, the biotoxicity effect became evident with the addition of much higher levels of MWCNTs addition. This study supports the possibility that carbon nanotubes accelerate interspecies electron transfer and provides a theoretical basis for the MWCNTs application in the process of anaerobic wastewater treatment.


Assuntos
Geobacter/efeitos dos fármacos , Nanotubos de Carbono/toxicidade , Aderência Bacteriana , Biomassa , Meios de Cultura , Transporte de Elétrons , Etanol/metabolismo , Geobacter/metabolismo , Especificidade da Espécie
7.
Int J Nanomedicine ; 14: 6465-6480, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31616140

RESUMO

Purpose: Multiwalled carbon nanotubes (MWCNTs) have been known to enter the circulatory system via the lungs from inhalation exposure; however, its carcinogenicity and subsequent accumulation in other organs have not been adequately reported in the literature. Moreover, the safety of MWCNTs as a biomaterial has remained a matter of debate, particularly when the material enters the circulatory system. To address these problems, we used carcinogenic rasH2 transgenic mice to intravenously administer highly dispersed MWCNTs and to evaluate their carcinogenicity and accumulation in the organs. Methods: Two types of MWCNTs (thin- and thick-MWCNTs) were intravenously administered at a high dose (approximately 0.7 mg per kg body weight) and low dose (approximately 0.07 mg per kg body weight). Results: MWCNTs showed pancreatic accumulation in 3.2% of mice administered with MWCNTs, but there was no accumulation in other organs. In addition, there was no significant difference in the incidence of tumor among the four MWCNTs-administered groups compared to the vehicle group without MWCNTs administration. Blood tests revealed elevated levels in mean red blood cell volume and mean red blood cell hemoglobin level for the MWCNTs-administered group, in addition to an increase in eotaxin. Conclusion: The present study demonstrated that the use of current technology to sufficiently disperse MWCNTs resulted in minimal organ accumulation with no evidence of carcinogenicity.


Assuntos
Carcinógenos/toxicidade , Nanotubos de Carbono/toxicidade , Administração Intravenosa , Animais , Peso Corporal , Carcinogênese/patologia , Citocinas/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/patologia , Masculino , Camundongos Transgênicos , Nanotubos de Carbono/ultraestrutura , Análise de Sobrevida , Distribuição Tecidual/efeitos dos fármacos
8.
Expert Rev Med Devices ; 16(10): 863-875, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31550943

RESUMO

Introduction: Tuberculosis (TB) remains one of the most alarming worldwide infectious diseases primarily in low-income countries, where the infection shows a higher and unvaried prevalence. In the last years, the emergence and spread of Mycobacterium tuberculosis (Mtb) strains resistant to first-line anti-TB drugs are the cause of major concern and prompted the implementation of new treatments, including the development of new drugs and the repurposing of old ones. Areas covered: In this review, we discuss solutions against TB based on nanomaterials (NMTs), alone or combined with current anti-TB drugs. We will summarize drug delivery platforms tested in in vivo or in vitro models and their activity against mycobacteria. We will describe how the new nanotechnologies based on carbon nanomaterials, like carbon nanotubes and graphene oxide are now facing the panorama of the medical fight against TB. Expert opinion: We foresee that in the next decade carbon nanomaterials will be at the forefront in fighting emerging antibiotic-resistant Mtb strains by shortening treatment periods, reducing adverse effects and mitigating antibiotic use. However, toxicity and biodegradation studies should be done prior to the clinical translation of carbon nanomaterials.


Assuntos
Grafite/uso terapêutico , Nanotubos de Carbono/química , Tuberculose/terapia , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Sistemas de Liberação de Medicamentos , Grafite/química , Humanos , Mycobacterium tuberculosis/efeitos dos fármacos , Nanotubos de Carbono/toxicidade , Tuberculose/tratamento farmacológico , Tuberculose/microbiologia
9.
IET Nanobiotechnol ; 13(6): 597-601, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31432792

RESUMO

Nanobiotechnology is a promising field concerned with the using of engineered nanomaterials, which leads to the improvement of new human remedial against pathogenic bacteria modalities. In this work, silver nanoparticles (AgNPs) were prepared by an easy, cheap and low-cost electro-chemical method. The AgNPs were then loaded successfully on to multi-walled carbon nanotubes (MWCNTs) using a modified chemical reaction process. The AgNPs on the MWCNTs were well spread and evenly distributed on the surfaces of the long nanotubes with well-graphitised walls as examined by high-resolution transmission electron microscopy. X-ray diffraction and transmission electron microscopy were used for sample characterisation. Good dispersion of AgNPs was obtained on the surface of MWCNTs, resulting in an efficient reactivity of the carbon nanotubes surfaces. Finally, the antibacterial activity of AgNPs/MWCNTs hybrid was evaluated against two pathogenic bacteria Pseudomonas aeruginosa and Staphylococcus aureus exhibited excellent activity.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Nanotubos de Carbono , Antibacterianos/química , Bactérias/patogenicidade , Escherichia coli , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Nanotubos de Carbono/química , Nanotubos de Carbono/microbiologia , Nanotubos de Carbono/toxicidade , Pseudomonas aeruginosa , Prata/química , Prata/farmacologia , Staphylococcus aureus , Propriedades de Superfície
10.
Ecotoxicol Environ Saf ; 183: 109507, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31386942

RESUMO

Multi-walled carbon nanotubes (MWCNTs) promote biodegradation in water treatment, but the effect of MWCNT on denitrification under aerobic conditions is still unclear. This investigation focused on the denitrification performance of MWCNT and its toxic effects on Alcaligenes sp. TB which showed that 30 mg/L MWCNTs increased NO3- removal efficiency from 84% to 100% and decreased the NO2-and N2O accumulation rates by 36% and 17.5%, respectively. Nitrite reductase and nitrous oxide reductase activities were further increased by 19.5% and 7.5%, respectively. The mechanism demonstrated that electron generation (NADH yield) and electron transportation system activity increased by 14.5% and 104%, respectively. Cell membrane analysis found that MWCNT caused an increase in polyunsaturated fatty acids, which had positive effects on electron transportation and membrane fluidity at a low concentration of 96 mg/kg but caused membrane lipid peroxidation and impaired membrane integrity at a high concentration of 115 mg/L. These findings confirmed that MWCNT affects the activity of Alcaligenes sp. TB and consequently enhances denitrification performance.


Assuntos
Alcaligenes/metabolismo , Desnitrificação/fisiologia , Nanotubos de Carbono , Purificação da Água/métodos , Biodegradação Ambiental , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Desnitrificação/efeitos dos fármacos , Transporte de Elétrons , Ácidos Graxos Insaturados/metabolismo , NAD/metabolismo , Nanotubos de Carbono/toxicidade , Nitratos/isolamento & purificação
11.
Inhal Toxicol ; 31(5): 192-202, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31345048

RESUMO

Background: Increasing evidence from rodent studies indicates that inhaled multi-walled carbon nanotubes (MWCNTs) have harmful effects on the lungs. In this study, we examined the effects of inhalation exposure to MWCNTs on allergen-induced airway inflammation and fibrosis. We hypothesized that inhalation pre-exposure to MWCNTs would render mice susceptible to developing allergic lung disease induced by house dust mite (HDM) allergen. Methods: Male B6C3F1/N mice were exposed by whole-body inhalation for 6 h a day, 5 d a week, for 30 d to air control or 0.06, 0.2, and 0.6 mg/m3 of MWCNTs. The exposure atmospheres were agglomerates (1.4-1.8 µm) composed of MWCNTs (average diameter 16 nm; average length 2.4 µm; 0.52% Ni). Mice then received 25 µg of HDM extract by intranasal instillation 6 times over 3 weeks. Necropsy was performed at 3 and 30 d after the final HDM dose to collect serum, bronchoalveolar lavage fluid (BALF), and lung tissue for histopathology. Results: MWCNT exposure at the highest dose inhibited HDM-induced serum IgE levels, IL-13 protein levels in BALF, and airway mucus production. However, perivascular and peribronchiolar inflammatory lesions were observed in the lungs of mice at 3 d with MWCNT and HDM, but not MWCNT or HDM alone. Moreover, combined HDM and MWCNT exposure increased airway fibrosis in the lungs of mice. Conclusions: Inhalation pre-exposure to MWCNTs inhibited HDM-induced TH2 immune responses, yet this combined exposure resulted in vascular inflammation and airway fibrosis, indicating that MWCNT pre-exposure alters the immune response to allergens.


Assuntos
Antígenos de Dermatophagoides/imunologia , Hipersensibilidade/fisiopatologia , Exposição por Inalação/efeitos adversos , Pulmão/fisiologia , Nanotubos de Carbono/toxicidade , Animais , Líquido da Lavagem Broncoalveolar , Relação Dose-Resposta Imunológica , Fibrose , Imunoglobulina E/sangue , Interleucina-13/análise , Masculino , Camundongos , Células Th2/imunologia
12.
Toxicol Ind Health ; 35(7): 497-506, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31272286

RESUMO

Single-walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs) are broadly applicable across a variety of industrial fields. Despite their usefulness in many different applications, oxidative stress-induced toxicity of SWCNTs and MWCNTs has not been widely investigated. The present study examined the effects of SWCNTs and MWCNTs on rat brain mitochondria using the 3,4 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and indices of reactive oxygen species (ROS), based on measurements of malondialdehyde (MDA), glutathione (GSH), and mitochondrial membrane potential. Based on the MTT assay, exposure to SWCNTs and MWCNTs decreased mitochondrial survival and viability in a dose-dependent manner. Findings also indicated that MWCNTs and SWCNTs could damage mitochondrial membranes and induce the formation of ROS, as indicated by increased levels of MDA and decreased GSH content. The results of this study suggest that SWCNTs and MWCNTs likely damage brain tissue mitochondria by increasing oxidative stress and possibly activating the apoptosis pathway as well as other pathways of cytotoxicity.


Assuntos
Encéfalo/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Nanotubos de Carbono/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Animais , Sobrevivência Celular , Relação Dose-Resposta a Droga , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Ratos , Ratos Wistar
13.
Int J Mol Sci ; 20(11)2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31146342

RESUMO

As the demand for multi-walled carbon nanotube (MWCNT) incorporation into industrial and biomedical applications increases, so does the potential for unintentional pulmonary MWCNT exposure, particularly among workers during manufacturing. Pulmonary exposure to MWCNTs raises the potential for development of lung inflammation, fibrosis, and cancer among those exposed; however, there are currently no effective biomarkers for detecting lung fibrosis or predicting the risk of lung cancer resulting from MWCNT exposure. To uncover potential mRNAs and miRNAs that could be used as markers of exposure, this study compared in vivo mRNA and miRNA expression in lung tissue and blood of mice exposed to MWCNTs with in vitro mRNA and miRNA expression from a co-culture model of human lung epithelial and microvascular cells, a system previously shown to have a higher overall genome-scale correlation with mRNA expression in mouse lungs than either cell type grown separately. Concordant mRNAs and miRNAs identified by this study could be used to drive future studies confirming human biomarkers of MWCNT exposure. These potential biomarkers could be used to assess overall worker health and predict the occurrence of MWCNT-induced diseases.


Assuntos
Pneumopatias/sangue , Pulmão/metabolismo , MicroRNAs/sangue , Nanotubos de Carbono/toxicidade , RNA Mensageiro/sangue , Animais , Biomarcadores/sangue , Biomarcadores/metabolismo , Linhagem Celular , Células Cultivadas , Humanos , Pulmão/efeitos dos fármacos , Pneumopatias/etiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , MicroRNAs/metabolismo , Exposição Ocupacional , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
14.
J Mater Sci Mater Med ; 30(5): 54, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31041537

RESUMO

The in vitro cytotoxicity of both the multiwalled carbon nanotubes (MWCNT) in suspension with culture medium and the tetracalcium phosphate/monetite cement with addition of 0.8 wt% of MWCNTs on fibroblasts and osteoblasts were studied. The cytotoxicity was evaluated by MTS test (formazan) and live/dead staining. No cytotoxicity of MWCNT extract was measured contrary to about 60% reduction in proliferation of fibroblasts in MWCNT suspension as compared with negative control. The several contact cytotoxicity of MWCNT composite cement surfaces on seeded cells was demonstrated by MTS test and live/dead staining of damaged fibroblasts and dead osteoblasts after 72 h of culture. The detailed microstructure analysis showed a significant refinement of the surface texture due to the formation of thin needle-like hydroxyapatite particles on MWCNTs and this effect could be responsible for cytotoxicity of composites.


Assuntos
Cimentos para Ossos/química , Cimentos para Ossos/toxicidade , Fosfatos de Cálcio/química , Fosfatos de Cálcio/toxicidade , Nanotubos de Carbono/química , Nanotubos de Carbono/toxicidade , Animais , Materiais Biocompatíveis , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Teste de Materiais , Camundongos
15.
Chem Biol Interact ; 307: 206-222, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31054282

RESUMO

Application of nanomaterials in our daily life is increasing, day in day out and concerns have raised about their toxicity for human and other organisms. In this manner, carbon-based nanomaterials have been applied to different products due to their unique physicochemical, electrical, mechanical properties, and biological compatibility. But, there are several reports about the negative effects of these materials on biological systems and cellular compartments. This review article describes the various types of carbon-based nanomaterials and methods that use for determining these toxic effects that are reported recently in the papers. Then, extensively discussed the toxic effects of these materials on the human and other living organisms and also their toxicity routs including Neurotoxicity, Hepatotoxicity, Nephrotoxicity, Immunotoxicity, Cardiotoxicity, Genotoxicity and epigenetic toxicity, Dermatotoxicity, and Carcinogenicity.


Assuntos
Carbono/química , Nanoestruturas/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Fulerenos/química , Fulerenos/toxicidade , Grafite/química , Grafite/toxicidade , Humanos , Nanoestruturas/toxicidade , Nanotubos de Carbono/química , Nanotubos de Carbono/toxicidade , Estresse Oxidativo/efeitos dos fármacos
16.
IEEE Trans Nanobioscience ; 18(3): 463-468, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31056505

RESUMO

Human mesenchymal stem cells (hMSCs) have attracted significant attention for tissue engineering because of their ability to differentiate into bone cells, chondrocytes, adipocytes, and muscle cells. Single-walled carbon nanotubes (SWCNTs) have been considered as a potential material for tissue engineering applications due to their unique properties, such as high aspect ratio, excellent electrocatalytic activity, and biocompatibility. Here we prepared exfoliated SWCNTs layers through an ultra-sonication process in the acidic medium and evaluated their cytotoxicity using hMSCs. Improved viability and osteogenesis of hMSCs were observed in the presence of exfoliated SWCNTs. Besides, the higher expression of osteogenic differentiation-related genes in the presence of exfoliated SWCNTs further confirmed their enhanced osteogenic nature. These results indicated the potential of SWCNTs as a biomaterial for tissue engineering applications.


Assuntos
Técnicas de Cultura de Células/métodos , Células-Tronco Mesenquimais , Nanotubos de Carbono , Osteogênese/efeitos dos fármacos , Materiais Biocompatíveis/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Nanotubos de Carbono/química , Nanotubos de Carbono/toxicidade
17.
Chemosphere ; 230: 369-376, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31108448

RESUMO

Although traditional water treatment systems can remove various substances from wastewater, these conventional systems fail to remove many chemical molecules that pose potential ecological and health risks. Carbon nanotubes (CNTs) appear attractive to adsorption of many substances, but CNTs adsorbed with toxic substances becomes a nanocomposite still more toxic. Here, we employ zebrafish embryos as biosensor to examine how a hybrid micro/nanostructured carbonaceous material (HMNC) derived from a combination of activated carbon (AC) with hydrophilic carbon nanotubes (CNTs) can remediate wastewater contaminated with the pharmaceutical fluoxetine hydrochloride (FLX). AC and HMNC are practically non-toxic to zebrafish embryos (LC50 > 1000 mg.L-1). HMNC addition to culture medium containing FLX significantly reduces sublethal effects and lethality. Interaction between FLX and HMNC involves chemical adsorption such that embryo co-exposure to HMNC adsorbed with FLX in the range of concentrations evaluated herein does not elicit any behavioral changes in zebrafish.


Assuntos
Carvão Vegetal/toxicidade , Embrião não Mamífero/efeitos dos fármacos , Fluoxetina/toxicidade , Nanocompostos/toxicidade , Nanotubos de Carbono/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra , Adsorção , Animais , Comportamento Animal/efeitos dos fármacos , Carvão Vegetal/química , Recuperação e Remediação Ambiental/métodos , Fluoxetina/química , Dose Letal Mediana , Nanocompostos/química , Nanotubos de Carbono/química , Águas Residuárias/química , Poluentes Químicos da Água/química
18.
Environ Sci Pollut Res Int ; 26(20): 20742-20752, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31104242

RESUMO

Although the increased production of nanoparticles (NPs) has raised extensive concerns about the potential toxic effects on aquatic organisms, as well as the increasing evidences which documented the impact of ocean acidification (OA) on the physiology and fitness of marine invertebrates, limited number of studies reported their combined toxic effects. For these reasons, in the present study, we investigated the physiological and biochemical responses of one of the most economically important bivalve species in the World, the Manila clam Ruditapes philippinarum, after the exposure to an environmnetally relevant concentration of carboxylated carbon nanotubes and predicted OA conditions. The results showed that the organisms were not only susceptible to NPs but also to seawater acidification. Different responses between low pH and NPs for most tested biomarkers were observed, both in terms of physiological (respiration rate) and biochemical responses (metabolic capacity, oxitative status and neurotoxicity). Acidified pH significantly decreased the respiration rate and metabolism and increased the energy reserves consumption. Moreover, increase of the oxidative damage was also detected under this condition confirming that the mechanism of enhanced toxicity in the organisms should be attributed to lower aggregation state with more suspended NPs in acidified seawater, indicating that seawater acidification significantly influenced the impact of the used NPs in the exposed organisms.


Assuntos
Bivalves/fisiologia , Ácidos Carboxílicos/toxicidade , Nanotubos de Carbono/toxicidade , Água do Mar/química , Poluentes Químicos da Água/toxicidade , Animais , Disponibilidade Biológica , Biomarcadores/metabolismo , Bivalves/efeitos dos fármacos , Bivalves/metabolismo , Ácidos Carboxílicos/química , Concentração de Íons de Hidrogênio , Nanotubos de Carbono/química , Estresse Oxidativo , Poluentes Químicos da Água/química
19.
Part Fibre Toxicol ; 16(1): 15, 2019 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-30943996

RESUMO

BACKGROUND: Multi-walled carbon nanotubes (MWCNT) have been shown to elicit the release of inflammatory and pro-fibrotic mediators, as well as histopathological changes in lungs of exposed animals. Current standards for testing MWCNTs and other nanoparticles (NPs) rely on low-throughput in vivo studies to assess acute and chronic toxicity and potential hazard to humans. Several alternative testing approaches utilizing two-dimensional (2D) in vitro assays to screen engineered NPs have reported conflicting results between in vitro and in vivo assays. Compared to conventional 2D in vitro or in vivo animal model systems, three-dimensional (3D) in vitro platforms have been shown to more closely recapitulate human physiology, providing a relevant, more efficient strategy for evaluating acute toxicity and chronic outcomes in a tiered nanomaterial toxicity testing paradigm. RESULTS: As inhalation is an important route of nanomaterial exposure, human lung fibroblasts and epithelial cells were co-cultured with macrophages to form scaffold-free 3D lung microtissues. Microtissues were exposed to multi-walled carbon nanotubes, M120 carbon black nanoparticles or crocidolite asbestos fibers for 4 or 7 days, then collected for characterization of microtissue viability, tissue morphology, and expression of genes and selected proteins associated with inflammation and extracellular matrix remodeling. Our data demonstrate the utility of 3D microtissues in predicting chronic pulmonary endpoints following exposure to MWCNTs or asbestos fibers. These test nanomaterials were incorporated into 3D human lung microtissues as visualized using light microscopy. Differential expression of genes involved in acute inflammation and extracellular matrix remodeling was detected using PCR arrays and confirmed using qRT-PCR analysis and Luminex assays of selected genes and proteins. CONCLUSION: 3D lung microtissues provide an alternative testing platform for assessing nanomaterial-induced cell-matrix alterations and delineation of toxicity pathways, moving towards a more predictive and physiologically relevant approach for in vitro NP toxicity testing.


Assuntos
Asbesto Crocidolita/toxicidade , Matriz Extracelular/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Modelos Biológicos , Nanotubos de Carbono/toxicidade , Alternativas aos Testes com Animais , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Matriz Extracelular/ultraestrutura , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Pulmão/ultraestrutura , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Testes de Toxicidade/métodos
20.
Mater Sci Eng C Mater Biol Appl ; 100: 616-630, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30948098

RESUMO

With advances in nanotechnology, the applications of nanomaterial are developing widely and greatly. The characteristic properties of carbon nanotubes (CNTs) make them the most selective candidate for various multi-functional applications. The greater surface area of the CNTs in addition to the capability to manipulate the surfaces and dimensions has provided greater potential for this nanomaterial. The CNTs possess greater potential for applications in biomedicine due to their vital electrical, chemical, thermal, and mechanical properties. The unique properties of CNT are exploited for numerous applications in the biomedical field. They are useful in both therapeutic and diagnostic applications. They form novel carrier systems which are also capable of site-specific delivery of therapeutic agents. In addition, CNTs are of potential application in biosensing. Many recently reported advanced systems of CNT could be exploited for their immense potential in biomedicine in the future.


Assuntos
Tecnologia Biomédica/métodos , Nanotubos de Carbono/química , Sistemas de Liberação de Medicamentos , Técnicas de Transferência de Genes , Nanotubos de Carbono/toxicidade , Nanotubos de Carbono/ultraestrutura , Medicina Regenerativa , Engenharia Tecidual
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA