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Nanomateriais ingeridos: impacto biológico e relação com as suas características físico-químicas
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Advisor(s)
Abstract(s)
A utilização de nanomateriais (NMs) em setores variados, designadamente, agricultura e indústria alimentar, encontra-se amplamente disseminada.
Assim, muitos produtos alimentares contêm NMs, sendo provável a sua ingestão pelo homem. Torna-se, pois, essencial garantir que esses NMs ingeridos não produzem efeitos adversos, nomeadamente, genotoxicidade
que se relaciona com carcinogénese. Neste estudo, pretendemos avaliar
uma possível associação entre as propriedades físico-químicas de NMs
com a mesma constituição química, dióxido de titânio (TiO2), e os seus
efeitos biológicos em células humanas e, por outro lado, identificar as propriedades que determinam a sua toxicidade. Para tal, analisou-se a citotoxicidade de um conjunto de quatro NMs de TiO2 tendo-se observado que
apenas um deles induzia morte celular. Relativamente aos efeitos genotóxicos, apesar de nenhum NM ter induzido alterações cromossómicas (ensaio
do micronúcleo), observou-se que apenas os NMs na forma cristalina anatase (mas não rutilo) induziam efeitos lesivos no DNA (ensaio do cometa).
Neste último ensaio, verificou-se ainda a existência de uma correlação inversa entre o tamanho do NM em meio de cultura e a sua genotoxicidade.
Futuramente, investigaremos o efeito do processo de digestão nas características destes NMs, bem como nos seus efeitos genotóxicos in vitro, visando a tradução dos resultados em potenciais implicações na saúde humana.
The use of nanomaterials (NMs) in a variety of sectors, e.g., agriculture and the food industry, is widely disseminated. Thus, many food products contain NMs that are likely to be consumed by humans. It is therefore essential to ensure that these ingested NMs do not produce adverse effects, namely genotoxicity which is related to carcinogenesis. In this study, we intended to evaluate a possible association between the physicochemical properties of NMs with the same chemical constitution, titanium dioxide (TiO2 ), and their biological effects on human cells and, on the other hand, to identify the properties that determine their toxicity. For this purpose, the cytotoxicity of a set of four TiO2 NMs was analysed and the results showed that only one of them was able to induce cell death. Regarding the genotoxic effects, although none of them induced chromosomal changes (micronucleus assay), the NMs in the anatase (but not rutile) crystalline form were able to induce DNA damage (comet assay). In the latter assay the existence of an inverse correlation between the NM size in culture medium and its genotoxicity was also verified. In the future, we will investigate the effect of the digestion process on the characteristics of these NMs, as well as on their genotoxic effects in vitro, with the goal of translating the results into potential implications for human health.
The use of nanomaterials (NMs) in a variety of sectors, e.g., agriculture and the food industry, is widely disseminated. Thus, many food products contain NMs that are likely to be consumed by humans. It is therefore essential to ensure that these ingested NMs do not produce adverse effects, namely genotoxicity which is related to carcinogenesis. In this study, we intended to evaluate a possible association between the physicochemical properties of NMs with the same chemical constitution, titanium dioxide (TiO2 ), and their biological effects on human cells and, on the other hand, to identify the properties that determine their toxicity. For this purpose, the cytotoxicity of a set of four TiO2 NMs was analysed and the results showed that only one of them was able to induce cell death. Regarding the genotoxic effects, although none of them induced chromosomal changes (micronucleus assay), the NMs in the anatase (but not rutile) crystalline form were able to induce DNA damage (comet assay). In the latter assay the existence of an inverse correlation between the NM size in culture medium and its genotoxicity was also verified. In the future, we will investigate the effect of the digestion process on the characteristics of these NMs, as well as on their genotoxic effects in vitro, with the goal of translating the results into potential implications for human health.
Description
Keywords
Nanomateriais Doenças Genéticas
Citation
Boletim Epidemiológico Observações. 2019 janeiro-abril;8(24):35-38
Publisher
Instituto Nacional de Saúde Doutor Ricardo Jorge, IP