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1.
Regul Toxicol Pharmacol ; 138: 105312, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36565917

RESUMO

OPINION TO BE CITED AS: SCCS (Scientific Committee on Consumer Safety), scientific opinion on Butylated hydroxytoluene (BHT), preliminary version of September 27, 2021, final version of December 2, 2021, SCCS/1636/21.


Assuntos
Hidroxitolueno Butilado , Cosméticos , Medição de Risco , Qualidade de Produtos para o Consumidor , Atitude
2.
Regul Toxicol Pharmacol ; 140: 105364, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36907371

RESUMO

Opinion to be cited as: SCCS (Scientific Committee on Consumer Safety), Opinion on Acid Yellow 3 - C054 (CAS Number 8004-92-0, EC No 305-897-5), submission II, preliminary version of 7 May 2021, final version of 23 July 2021, SCCS/1631/21.


Assuntos
Cosméticos , Medição de Risco , Qualidade de Produtos para o Consumidor , Atitude
3.
Regul Toxicol Pharmacol ; 126: 105046, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34560169

RESUMO

The Cosmetic Regulation (EC) No 1223/2009 specifically covers the risk of nanomaterials used in cosmetic products. If there are concerns regarding the safety of a nanomaterial, the European Commission refers it to the SCCS for a scientific opinion. The Commission mandated the SCCS to identify the scientific basis for safety concerns that could be used as a basis for identifying and prioritising nanomaterials for safety assessment, and to revisit previous inconclusive SCCS opinions on nanomaterials to identify any concerns for potential risks to the consumer health. The SCCS Scientific Advice identified the key general aspects of nanomaterials that should raise a safety concern for a safety assessor/manager, so that the nanomaterial(s) in question could be subjected to safety assessment to establish safety to the consumer. The Advice also developed a list of the nanomaterials notified to the Commission for use in cosmetics in an order of priority for safety assessment, and revisited three previous inconclusive opinions on nanomaterials to highlight concerns over consumer safety that merited further safety assessment.


Assuntos
Qualidade de Produtos para o Consumidor/normas , Cosméticos/efeitos adversos , Nanoestruturas/efeitos adversos , Relação Dose-Resposta a Droga , Europa (Continente) , Humanos , Tamanho da Partícula , Medição de Risco , Solubilidade , Propriedades de Superfície
4.
Bioconjug Chem ; 29(7): 2248-2256, 2018 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-29906097

RESUMO

Biocompatible thermoresponsive copolymers based on 2-(2-methoxyethoxy) ethyl methacrylate (MEO2MA) and oligo (ethylene glycol) methacrylate (OEGMA) were grown from the surface of ZnO quantum dots (QDs) by surface initiated atom transfer radical polymerization with activators regenerated by electron transfer (SI-ARGET ATRP) in order to design smart and fluorescent core/shell nanosystems to be used toward cancer cells. Tunable lower critical solution temperature (LCST) values were obtained and studied in water and in culture medium. The complete efficiency of the process was demonstrated by the combination of spectroscopic and microscopic studies. The colloidal behavior of the ZnO/copolymer core/shell QDs in water and in physiological media with temperature was assessed. Finally, the cytotoxicity toward human colon cancer HT29 cells of the core/shell QDs was tested. The results showed that the polymer-capped QDs exhibited almost no toxicity at concentrations up to 12.5 µg.mL-1, while when loaded with doxorubicin hydrochloride (DOX), a higher cytotoxicity and a decreased HT29 cancer cell viability in a short time were observed.


Assuntos
Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Neoplasias/tratamento farmacológico , Pontos Quânticos/uso terapêutico , Sobrevivência Celular/efeitos dos fármacos , Coloides , Doxorrubicina/farmacologia , Células HT29 , Humanos , Metacrilatos/química , Polimerização , Pontos Quânticos/química , Pontos Quânticos/toxicidade , Óxido de Zinco
5.
Nanotechnology ; 28(12): 125601, 2017 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-28145892

RESUMO

Core/shell nanostructures based on silica, fluorescent ZnO quantum dots (QDs) and superparamagnetic Fe3O4 nanoparticles (NPs) were prepared and fully characterized by the combination of different techniques and the physical properties of the nanostructures were studied. We demonstrate the efficiency of the atom transfer radical polymerization with activators regenerated by electron transfer process to graft (co-)polymers of different structures and polarity at the surface of metal oxide NPs. The influence of the polymer chain configuration on the optical properties of the ZnO/polymer core/shell QDs was enlightened. Concerning the magnetic properties of the Fe3O4/polymer nanostructures, only the amount of the grafted polymer plays a role on the saturation magnetization of the NPs and no influence of the aggregation was evidenced. The simple and fast process described in this work is efficient for the grafting of copolymers from surfaces and the derived NPs display the combination of the physical properties of the core and the macromolecular behavior of the shell.

6.
Chem Soc Rev ; 42(18): 7571-637, 2013 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-23558752

RESUMO

The aim of this review article on recent developments of mechanochemistry (nowadays established as a part of chemistry) is to provide a comprehensive overview of advances achieved in the field of atomistic processes, phase transformations, simple and multicomponent nanosystems and peculiarities of mechanochemical reactions. Industrial aspects with successful penetration into fields like materials engineering, heterogeneous catalysis and extractive metallurgy are also reviewed. The hallmarks of mechanochemistry include influencing reactivity of solids by the presence of solid-state defects, interphases and relaxation phenomena, enabling processes to take place under non-equilibrium conditions, creating a well-crystallized core of nanoparticles with disordered near-surface shell regions and performing simple dry time-convenient one-step syntheses. Underlying these hallmarks are technological consequences like preparing new nanomaterials with the desired properties or producing these materials in a reproducible way with high yield and under simple and easy operating conditions. The last but not least hallmark is enabling work under environmentally friendly and essentially waste-free conditions (822 references).

7.
Macromol Biosci ; 23(3): e2200434, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36448191

RESUMO

Ovarian cancer remains a major public health issue due to its poor prognosis. To develop more effective therapies, it is crucial to set-up reliable models that closely mimic the complexity of the ovarian tumor's microenvironment. 3D bioprinting is currently a promising approach to build heterogenous and reproducible cancer models with controlled shape and architecture. However, this technology is still poorly investigated to model ovarian tumors. In this study, a 3D bioprinted ovarian tumor model combining cancer cells (SKOV-3) and cancer associated fibroblasts (CAFs) are described. The resulting tumor models show their ability to maintain cell viability and proliferation. Cells are observed to self-assemble in heterotypic aggregates. Moreover, CAFs are observed to be recruited and to circle cancer cells reproducing an in vivo process taking place in the tumor microenvironment. Interestingly, this approach also shows its ability to rapidly generate a high number of reproducible tumor models that can be subjected to usual characterizations (cell viability and metabolic activity; histology and immunological studies; and real-time imaging). Therefore, these ovarian tumor models can be an interesting tool for high throughput drug screening applications.


Assuntos
Bioimpressão , Fibroblastos Associados a Câncer , Neoplasias Ovarianas , Feminino , Humanos , Técnicas de Cocultura , Fibroblastos Associados a Câncer/patologia , Neoplasias Ovarianas/patologia , Linhagem Celular Tumoral , Esferoides Celulares/patologia , Microambiente Tumoral
8.
EFSA J ; 21(7): e08106, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37522100

RESUMO

Calcium carbonate (E 170) was re-evaluated in 2011 by the former EFSA Panel on Food Additives and Nutrient sources added to Food (ANS). As a follow-up to this assessment, the Panel on Food Additives and Flavourings (FAF) was requested to assess the safety of calcium carbonate (E 170) for its uses as a food additive in food for infants below 16 weeks of age belonging to food category 13.1.5.1 (Dietary foods for infants for special medical purposes and special formulae for infants) and as carry over in line with Annex III, Part 5 Section B to Regulation (EC) No 1333/2008. In addition, the FAF Panel was requested to address the issues already identified during the re-evaluation of the food additive when used in food for the general population. The process involved the publication of a call for data to allow the interested business operators (IBOs) to provide the requested information to complete the risk assessment. The Panel concluded that there is no need for a numerical acceptable daily intake (ADI) for calcium carbonate and that, in principle, there are no safety concern with respect to the exposure to calcium carbonate per se at the currently reported uses and use levels in all age groups of the population, including infants below 16 weeks of age. With respect to the calcium intake resulting from the use of E 170 in food for the general population and infants < 16 weeks of age, the Panel concluded that it contributes only to a small part to the overall calcium dietary exposure. However, the unavoidable presence of aluminium in E 170 is of concern and should be addressed. In addition, the Panel concluded that the technical data provided by the IBO support further amendments of the specifications for E 170 laid down in Commission Regulation (EU) No 231/2012.

9.
ACS Omega ; 5(10): 4770-4777, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32201762

RESUMO

Designing and manufacturing multifunctional nanoparticles (NPs) are of considerable interest for both academic and industrial research. Among NPs used in this field, iron oxide NPs show low toxicity compared to metallic ones and are thus of high interest for biomedical applications. In this work, superparamagnetic Fe3-δO4-based core/shell NPs were successfully prepared and characterized by the combination of different techniques, and their physical properties were investigated. We demonstrate the efficiency of the layer-by-layer process to graft polyelectrolytes on the surface of iron oxide NPs. The influence of the polyelectrolyte chain configuration on the magnetic properties of the Fe3-δO4/polymer core/shell NPs was enlightened. The simple and fast process described in this work is efficient for the grafting of polyelectrolytes from surfaces, and thus, derived Fe3-δO4 NPs display both the physical properties of the core and of the macromolecular shell. Finally, the cytotoxicity toward the human THP-1 monocytic cell line of the core/shell NPs was assessed. The results showed that the polymer-capped Fe3-δO4 NPs exhibited almost no toxicity after 24 h of exposure at concentrations up to 25 µg mL-1. Our results show that these smart superparamagnetic nanocarriers with stealth properties are promising for applications in multimodal cancer therapy, including drug delivery.

10.
Toxicology ; 436: 152421, 2020 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-32119890

RESUMO

Although the need for non-animal alternatives has been well recognised for the human health hazard assessment of chemicals in general, it has become especially pressing for cosmetic ingredients due to the full implementation of testing and marketing bans on animal testing under the European Cosmetics Regulation. This means that for the safety assessment of cosmetics, the necessary safety data for both the ingredients and the finished product can be drawn from validated (or scientifically-valid), so-called "Replacement methods". In view of the challenges for safety assessment without recourse to animal test data, the Methodology Working Group of the Scientific Committee on Consumer Safety organised a workshop in February 2019 to discuss the key issues in regard to the use of animal-free alternative methods for the safety evaluation of cosmetic ingredients. This perspective article summarises the outcomes of this workshop and reflects on the state-of-the-art and possible way forward for the safety assessment of cosmetic ingredients for which no experimental animal data exist. The use and optimisation of "New Approach Methodology" that could be useful tools in the context of the "Next Generation Risk Assessment" and the strategic framework for safety assessment of cosmetics were discussed in depth.


Assuntos
Alternativas aos Testes com Animais/tendências , Cosméticos/efeitos adversos , Testes de Toxicidade/tendências , Animais , Simulação por Computador , Qualidade de Produtos para o Consumidor , Cosméticos/classificação , Cosméticos/farmacocinética , Difusão de Inovações , União Europeia , Previsões , Humanos , Modelos Biológicos , Medição de Risco , Relação Estrutura-Atividade
11.
Nanotechnology ; 20(23): 235602, 2009 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-19451687

RESUMO

A new fabrication method to produce homogeneously fluorescent nanodiamonds with high yields is described. The powder obtained by high energy ball milling of fluorescent high pressure, high temperature diamond microcrystals was converted in a pure concentrated aqueous colloidal dispersion of highly crystalline ultrasmall nanoparticles with a mean size less than or equal to 10 nm. The whole fabrication yield of colloidal quasi-spherical nanodiamonds was several orders of magnitude higher than those previously reported starting from microdiamonds. The results open up avenues for the industrial cost-effective production of fluorescent nanodiamonds with well-controlled properties.


Assuntos
Diamante/química , Fluorescência , Nanopartículas/química , Nanotecnologia/métodos , Carbono/química , Coloides/química , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Modelos Químicos , Nanopartículas/ultraestrutura , Nitrogênio/química , Pressão , Temperatura , Difração de Raios X
12.
ACS Appl Mater Interfaces ; 11(34): 30610-30620, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31359758

RESUMO

This study reports on the development of thermoresponsive core/shell magnetic nanoparticles (MNPs) based on an iron oxide core and a thermoresponsive copolymer shell composed of 2-(2-methoxy)ethyl methacrylate (MEO2MA) and oligo(ethylene glycol)methacrylate (OEGMA) moieties. These smart nano-objects combine the magnetic properties of the core and the drug carrier properties of the polymeric shell. Loading the anticancer drug doxorubicin (DOX) in the thermoresponsive MNPs via supramolecular interactions provides advanced features to the delivery of DOX with spatial and temporal controls. The so coated iron oxide MNPs exhibit superparamagnetic behavior with a saturation magnetization of around 30 emu g-1. Drug release experiments confirmed that only a small amount of DOX was released at room temperature, while almost 100% drug release was achieved after 52 h at 42 °C with Fe3-δO4@P(MEO2MA60OEGMA40), which grafted polymer chains displaying a low critical solution temperature of 41 °C. Moreover, the MNPs exhibit magnetic hyperthermia properties as shown by specific absorption rate measurements. Finally, the cytotoxicity of the core/shell MNPs toward human ovary cancer SKOV-3 cells was tested. The results showed that the polymer-capped MNPs exhibited almost no toxicity at concentrations up to 12 µg mL-1, whereas when loaded with DOX, an increase in cytotoxicity and a decrease of SKOV-3 cell viability were observed. From these results, we conclude that these smart superparamagnetic nanocarriers with stealth properties are able to deliver drugs to tumor and are promising for applications in multimodal cancer therapy.


Assuntos
Doxorrubicina , Portadores de Fármacos , Temperatura Alta , Hipertermia Induzida , Nanopartículas de Magnetita , Neoplasias , Linhagem Celular Tumoral , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Doxorrubicina/química , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Humanos , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/uso terapêutico , Neoplasias/metabolismo , Neoplasias/patologia , Neoplasias/terapia
13.
EFSA J ; 17(7): e05760, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32626376

RESUMO

The present opinion deals with the assessment of the data provided by interested business operators in support of an amendment of the EU specifications for titanium dioxide (E 171) with respect to the inclusion of additional parameters related to its particle size distribution. Titanium dioxide which is used as a food additive E 171 in food undergoes no surface treatment and is not coated. It consists of anatase or rutile generally containing small amounts of the other phase (rutile or anatase, < 2% m/m) and it may also contain small quantities (< 0.5%) of constituent particle growth and crystal phase control agents (alumina, sodium or potassium in combination with phosphate). Particle size analyses, by TEM, SEM, XDC or DC, have been carried out on five commercial brands of anatase E 171 and one of rutile E 171 manufactured by the only three EU manufacturers that, according to information submitted by interested business operators, produce food-grade titanium dioxide. Interested business operators proposed to introduce in the EU specifications for E 171 a specification of more than 100 nm for median Feret min diameter and less than 50% of the number of constituent particles below 100 nm; measured by EM in both cases. The Panel, after reviewing the data, concluded that a specification of more than 100 nm for median minimal external dimension, equivalent to less than 50% of the number of constituent particles with a median minimal external dimension below 100 nm, should be inserted in the current EU specifications. The Panel considered that the conclusions made, and the uncertainties identified, in the previous EFSA assessments on E 171 remain valid. The Panel reiterates the need for the further research as recommended in the previous opinions in order to decrease the level of uncertainty and acknowledged that additional studies with characterised E 171 are being carried out by interested business operators.

14.
Int J Pharm ; 532(2): 738-747, 2017 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-28893585

RESUMO

The unique physical properties of the superparamagnetic nanoparticles (SPIONs) have made them candidates of choice in nanomedicine especially for diagnostic imaging, therapeutic applications and drug delivery based systems. In this study, superparamagnetic Fe3O4 NPs were synthesized and functionalized with a biocompatible thermoresponsive copolymer to obtain temperature responsive core/shell NPs. The ultimate goal of this work is to build a drug delivery system able to release anticancer drugs in the physiological temperatures range. The core/shell NPs were first synthesized and their chemical, physical, magnetic and thermo-responsive properties where fully characterized in a second step. The lower critical solution temperature (LCST) of the core/shell NPs was tuned in physiological media in order to release the cancer drug at a controlled temperature slightly above the body temperature to avoid any premature release of the drug. The core/shell NPs exhibiting the targeted LCST were then loaded with Doxurubicin (DOX) and the drug release properties were then studied with the temperature. Moreover the cytotoxicity tests have shown that the core/shell NPs had a very limited cytotoxicity up to concentration of 25µg/mL. This investigation showed that the significant release occurred at the targeted temperature in the physiological media making those nano-systems very promising for further use in drug delivery platform.


Assuntos
Antineoplásicos/administração & dosagem , Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos , Nanopartículas de Magnetita/administração & dosagem , Polietilenoglicóis/administração & dosagem , Ácidos Polimetacrílicos/administração & dosagem , Antineoplásicos/química , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/química , Liberação Controlada de Fármacos , Células HT29 , Humanos , Nanopartículas de Magnetita/química , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Temperatura
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