Browsing by Issue Date, starting with "2021-05-05"
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- Early-stage nanosafety assessment as a critical tool for innovative nanomaterials developmentPublication . Louro, Henriqueta; Ventura, Célia; Rolo, Dora; Vital, Nádia; Pinto, Fátima; Silva, Maria JoãoThe perspectives of innovation through the use of nanomaterials (NMs) in key sectors such as agriculture, food industry, medicine, energy, environment, and electronics, has exponentially increased their development, production, and application. However, a major concern for public health is that some materials for long being considered safe for humans, e.g., titanium dioxide or cellulose fibers, can acquire different properties at the nanoscale that, despite being more attractive for industrial applications, may also elicit nano-bio interactions and toxic effects. Furthermore, their physicochemical properties can be influenced by the surrounding matrix or by physiological processes, such as digestion or inhalation, that modify their primary physicochemical properties. These secondary features may also influence the NMs toxicity and associated adverse health outcomes, such chronic inflammation and/or cancer. Therefore, the safety assessment of NMs must be conducted early in their development process and follow the nanotoxicology principles, in order to unveil the most relevant physicochemical characteristics that determine their potential adverse effects. In this work, the nanotoxicological investigation for the case studies of titanium dioxide NMs and nanocelluloses are presented. They illustrate the establishment of relationships between NMs characteristics and their toxicological properties and how they may direct the synthesis of innovative and safer NMs. If such tool is used at an early stage of NMs or product development, it moves industry towards a safe and sustainable by design (SSBD) approach that will enable safety to keep pace with innovation for the benefit of citizens. The Portuguese ISO/CEN Technical Commission for Nanotechnologies (CT194) is acknowledged for its role in bridging the gap between science and industry.
- Comparative assessment of the acute toxicity of commonly used metal nanoparticles in two in vitro models of human barriersPublication . Pires, J.; Moreira, L.; Teixeira, João; Fraga, SóniaMetal nanoparticles (M-NP) have application in several areas such as industry, environment, agriculture, and biomedicine. Consequently, human exposure to these nanosized materials is increasing, which raises serious concerns regarding their safety to the human health and the environment. Biological barriers are important lines of defence to xenobiotics, thus expected targets for M-NP. The present study investigated the in vitro toxicity of different types of M-NP in two cell models of biological barriers: human intestinal (Caco-2) and trophoblastic (BeWo clone b30) epithelial cells. Cells were exposed for 24 h to varied concentrations (0.8-48 µg/cm2) of M NP of different chemical composition (Au, Ag, TiO2), primary size (10, 30 and 60 nm), capping (citrate, PEG) and crystal structure (rutile, anatase) and toxicity assessed by determining changes in cell morphology, metabolic activity, plasma membrane integrity, generation of intracellular reactive oxygen species (ROS) and intracellular ATP levels. Our data show that the potential toxicity of the tested M-NPs is similar for both cell lines with AgNPs > AuNPs > TiO2NPs, being the effects more visible at higher concentrations. The influence of the size in the cytotoxic-induced effects was more evident for AgNP than for AuNP, with the smaller NP causing more toxicity, being the BeWo cells more sensitive to these M-NP. In addition, PEG-capping effectively attenuated AuNP-induced toxicity both in Caco-2 and BeWo cells. Only cells exposed to AgNP exhibited significant increased levels of ROS. Thus, our data support that the physicochemical properties of the nanomaterials, in this particular case of M-NP, is an important determinant of their cytotoxicity and that intestinal and trophoblastic cells exhibit different sensitivity to the tested M-NP. Future studies would be useful to further explore the effects of M-NP in the human barriers
- In vitro toxicity of metal nanoparticles in two human barrier models: role of the physicochemical featuresPublication . Pires, J; Moreira, L; Teixeira, J.P.; Fraga, S.Metal nanoparticles (M-NP) are among the most widely used nanomaterials in consumer products available in the market. Thus, human exposure to these nanosized materials is increasing, which raises serious concerns regarding their environmental and human safety. Biological barriers are important lines of defence to xenobiotics, thus expected targets for M-NP. The present study aimed at evaluating the in vitro toxicity of different M-NPs in two cell models of biological barriers: human intestinal (Caco-2) and trophoblastic (BeWo clone b30) epithelial cells. Cells were exposed for 24 h to varied concentrations (0.8-48 µg/cm2) of M-NP of different chemical composition (Au, Ag, TiO2), primary size (10, 30 and 60 nm), capping (citrate, PEG) and crystal structure (rutile, anatase) and toxicity assessed by determining changes in cell morphology, metabolic activity, plasma membrane integrity, generation of intracellular reactive oxygen species (ROS) and intracellular ATP levels. Our data show that the toxicity potential of the tested M-NP is similar in both cell lines with AgNPs > AuNPs > TiO2 NPs, being the effects more visible at higher concentrations. The influence of the size in the cytotoxic-induced effects was more evident for AgNP than for AuNP, with the smaller NP causing more toxicity, being the BeWo cells more sensitive to these M-NP. In addition, PEG-capping effectively attenuated AuNP-induced toxicity in both barrier models. In addition, only cells exposed to AgNP exhibited significant increased levels of ROS. Thus, our data support that the physicochemical properties of M-NP are an important determinant of their cytotoxicity and that intestinal and trophoblastic cells exhibit different sensitivity to the tested M-NP. Future studies would be useful to further explore the effects of M-NP in the human barriers.
- Exposição a micotoxinas e o seu impacto na saúde humana: desafios emergentesPublication . Alvito, PaulaSUMÁRIO: Micotoxinas; Implicações na Saúde; Exposição Humana; Alterações climáticas; Mensagens e desafios