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TiO2 NPs induce DNA damage in lymphocytes from healthy individuals and patients with respiratory diseases-An Ex vivo/In vitro StudyOsman, Ilham F., Najafzadeh, Mojgan, Sharma, Vyom, Shukla, Ritesh K, Jacob, B.K., Dhawan, A., Anderson, Diana 01 January 2018 (has links)
No / Nanotechnology has preceded nanotoxicology and little is known of the effects of nanoparticles in human systems, let alone in diseased individuals. Therefore, the effects of titanium dioxide (TiO2) nanoparticles in peripheral blood lymphocytes from patients with respiratory diseases [lung cancer, chronic obstructive pulmonary disease (COPD) and asthma] were compared with those in healthy Individuals, to determine differences in sensitivity to nanochemical insult. The Comet assay was performed according to recommended guidelines. The micronucleus assay and ras oncoprotein detection were conducted according to published standard methods. The results showed statistically significant concentration-dependent genotoxic effects of TiO2 NPs in both respiratory patient and control groups in the Comet assay. The TiO2 NPs caused DNA damage in a concentration dependent manner in both groups (respiratory and healthy controls) with the exception of the lowest TiO2 concentration (10 µg/ml) which did not induce significant damage in healthy controls (ns). When OTM data were used to compare the whole patient group and the control group, the patient group had more DNA damage (p > 0.001) with the exception of 10 µg/ml of TiO2 that caused less significant damage to patient lymphocytes (p < 0.05). Similarly, there was an increase in the pattern of cytogenetic damage measured in the MN assay without statistical significance except when compared to the negative control of healthy individuals. Furthermore, when modulation of ras p21 expression was investigated, regardless of TiO2 treatment, only lung cancer and COPD patients expressed measurable ras p21 levels. All results were achieved in the absence of cytotoxicity.
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Efeitos ecotoxicológicos das nanopartículas de dióxido de titânio sobre a alga Pseudokirchneriella Subcapitata e sobre o Cladócero Ceriodaphnia Silvestrii por diferentes vias de exposição / Ecotoxicological effects of the titanium dioxide nanoparticles on the algae Pseudokirchneriella subcapitata and on the cladoceran Ceriodaphnia silvestrii by different exposure routesLucca, Gisele Maria de 10 June 2016 (has links)
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Previous issue date: 2016-06-10 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / In recent years, increased use of titanium dioxide nanoparticles (TiO 2 NPs) in consumer
products and technological devices has raised concerns regarding their environmental
impacts and their risks to human health. Ecotoxicological studies have been used as a tool to analyze the toxic potential of TiO 2 NP S in different trophic levels, such as primary
producers (algae) and first order consumers (cladocerans). In the present study, the
chronic effects of TiO2 NPS on the population growth of the microalgae chlorophycean
Pseudokirchneriella subcapitata was evaluated during an exposure period of 96 hours,
under conditions of temperature and photoperiod similar to those found in tropical
ecosystems. New methods were developed for the separation of the aggregates between
the algae cells and TiO2 NPS, whose formation was observed at above 0.01 mg L-1
concentrations after a period of 96 hours’ exposure. The only effective method was the
one in which the cells were washed three times with a metal chelator (EDTA), with
duration of 1 minute for each wash. In the toxicity chronic test, there was obtained a
significant inhibition of algal growth from the concentration of 64 mg L-1 of TiO2 NPs,
with a concentration of 50% inhibition of algal cells (96 h - IC50) of 201.22 mg L -1 in 96
h of exposure. Then, it was evaluated the acute effects of exposure by contact and the
chronic effects of TiO2 NPs for the cladoceran Ceriodaphnia silvestrii, using
contaminated food (Pseudokirchneriella subcapitata) as a route of exposure. In acute
toxicity tests was obtained the average value of EC50 - 48 h of 77.57 mg L-1. In chronic
toxicity tests, it was observed significant differences in survival from the concentration
of 0.01 mg L-1, while for the body length, the number of eggs and neonates produced,
toxic effects were observed from the concentration of 1 mg L-1. These results indicate that
the nano-TiO2 NPS had a deleterious effect on the growth of Pseudokirchneriella
subcapitata only at concentrations above those normally found in natural aquatic
environments. For the cladoceran Ceriodaphnia silvestrii, the route of dietary exposure
indicated a greater toxic effect. / Nos últimos anos, o aumento do uso das nanopartículas de dióxido de titânio (nano-TiO2)
em produtos de consumo e em dispositivos tecnológicos tem gerado preocupações
relativas aos seus impactos ambientais e seus riscos à saúde humana. Estudos
ecotoxicológicos têm sido utilizados como uma ferramenta para analisar o potencial
tóxico das nano-TiO2 em diversos níveis tróficos, tais como produtores primários (algas)
e consumidores de primeira ordem (cladóceros). No presente estudo, os efeitos crônicos
das nano-TiO2 sobre o crescimento populacional da microalga clorofícea Pseudokirchneriella subcapitata foi avaliado durante um período de exposição de 96 horas, sob condições de temperatura e de fotoperíodo semelhantes às encontradas em ecossistemas de regiões tropicais. Foram desenvolvidas novas metodologias para separação dos agregados entre as células algais e as nano-TiO2, cuja formação foi
observada nas concentrações acima de 0,01 mg L -1 após um período de exposição de 96
horas. O único método eficiente foi aquele em que as células foram lavadas três vezes
com um quelante de metal (EDTA), com duração de 1 minuto para cada lavagem. No
teste de toxicidade crônico obteve-se inibição significativa do crescimento algal a partir
da concentração de 64 mg L-1 de nano-TiO2, com uma concentração de inibição a 50%
das células algais (CI 50 - 96h) de 201,22 mg L-1 em 96 h de exposição. Em seguida, foram
avaliados os efeitos agudos via exposição por contato e os efeitos crônicos das nano-TiO2
para o cladócero Ceriodaphnia silvestrii, utilizando o alimento (Pseudokirchneriella
subcapitata) contaminado como via de exposição. Nos testes de toxicidade aguda foi
obtido o valor médio de CE50 - 48 h de 77,57 mg L-1. Nos ensaios de toxicidade crônica,
diferenças significativas foram observadas na sobrevivência a partir da concentração de
0,01 mg L -1, enquanto que para o comprimento corporal, o número de ovos e o número
de neonatas produzidos, os efeitos tóxicos foram observados a partir da concentração de
1 mg L-1. Tais resultados indicam que as nano-TiO2 possuíram um efeito deletério sobre
o crescimento de Pseudokirchneriella subcapitata somente em concentrações acima
daquelas normalmente encontradas em ambientes aquáticos naturais. Para o cladócero
Ceriodaphnia silvestrii, a via de exposição alimentar indicou um maior efeito tóxico. / CNPq: 305698/2013-30 / FAPESP: 2014/14139-3 e 2016/00753-7
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