A road map toward a globally harmonized approach for occupational health surveillance and epidemiology in nanomaterial workers

OBJECTIVE: Few epidemiological studies have addressed the health of workers exposed to novel manufactured nanomaterials. The small current workforce will necessitate pooling international cohorts. METHOD: A road map was defined for a globally harmonized framework for the careful choice of materials, exposure characterization, identification of study populations, definition of health endpoints, evaluation of appropriateness of study designs, data collection and analysis, and interpretation of the results. RESULTS: We propose a road map to reach global consensus on these issues. The proposed strategy should ensure that the costs of action are not disproportionate to the potential benefits and that the approach is pragmatic and practical. CONCLUSIONS: We should aim to go beyond the collection of health complaints, illness statistics, or even counts of deaths; the manifestation of such clear endpoints would indicate a failure of preventive measures.

Limitations and information needs for engineered nanomaterial-specific exposure estimation and scenarios: recommendations for improved reporting practices

The aim of this paper is to describe the process and challenges in building exposure scenarios for engineered nanomaterials (ENM), using an exposure scenario format similar to that used for the European Chemicals regulation (REACH). Over 60 exposure scenarios were developed based on information from publicly available sources (literature, books, and reports), publicly available exposure estimation models, occupational sampling campaign data from partnering institutions, and industrial partners regarding their own facilities. The primary focus was on carbon-based nanomaterials, nano-silver (nano-Ag) and nano-titanium dioxide (nano-TiO2), and included occupational and consumer uses of these materials with consideration of the associated environmental release. The process of building exposure scenarios illustrated the availability and limitations of existing information and exposure assessment tools for characterizing exposure to ENM, particularly as it relates to risk assessment. This article describes the gaps in the information reviewed, recommends future areas of ENM exposure research, and proposes types of information that should, at a minimum, be included when reporting the results of such research, so that the information is useful in a wider context.

Biological impact assessment of nanomaterial used in nanomedicine. Introduction to the NanoTEST project.

Therapeutic nanoparticles (NPs) are used in nanomedicine as drug carriers or imaging agents, providing increased selectivity/specificity for diseased tissues. The first NPs in nanomedicine were developed for increasing the efficacy of known drugs displaying dose-limiting toxicity and poor bioavailability and for enhancing disease detection. Nanotechnologies have gained much interest owing to their huge potential for applications in industry and medicine. It is necessary to ensure and control the biocompatibility of the components of therapeutic NPs to guarantee that intrinsic toxicity does not overtake the benefits. In addition to monitoring their toxicity in vitro, in vivo and in silico, it is also necessary to understand their distribution in the human body, their biodegradation and excretion routes and dispersion in the environment. Therefore, a deep understanding of their interactions with living tissues and of their possible effects in the human (and animal) body is required for the safe use of nanoparticulate formulations. Obtaining this information was the main aim of the NanoTEST project, and the goals of the reports collected together in this special issue are to summarise the observations and results obtained by the participating research teams and to provide methodological tools for evaluating the biological impact of NPs.

Control of nanomaterial self-assembly in ultrasonically levitated droplets

We demonstrate that acoustic trapping can be used to levitate and manipulate droplets of soft matter, in particular, lyotropic mesophases formed from selfassembly of different surfactants and lipids, which can be analyzed in a contact-less manner by X-ray scattering in a controlled gas-phase environment. On the macroscopic length scale, the dimensions and the orientation of the particle are shaped by the ultrasonic field, while on the microscopic length scale the nanostructure can be controlled by varying the humidity of the atmosphere around the droplet. We demonstrate levitation and in situ phase transitions of micellar, hexagonal, bicontinuous cubic, and lamellar phases. The technique opens up a wide range of new experimental approaches of fundamental importance for environmental, biological, and chemical research.

New hydrazine sensors based on electropolymerized meso-tetra (4-sulphonatephenyl)porphyrinate manganese (III)/silver nanomaterial

A new electrocatalytic active porphyrin nanocomposite material was obtained by electropolymerization of meso-tetra(4-sulphonatephenyl) porphyrinate manganese(III) complex (MnTPPS) in alkaline solutions containing sub-micromolar concentrations of silver chloride. The modified glassy carbon electrodes efficiently oxidize hydrazine at 10 mV versus Ag/AgCl, dramatically decreasing the overpotential of conventional carbon electrodes. The analytical characteristics of this amperometric sensor coupled with batch injection analysis (BIA) technique were explored. Wide linear dynamic range (2.5 x 10(-7) to 2.5 x 10(-4) mol L-1), good repeatability (R.S.D. = 0.84%, n = 30) and low detection (3.1 x 10(-8) mol L-1) and quantification (1.0 x 10(-7) mol L-1) limits, as well as very fast sampling frequency (60 determinations per hour) were achieved. (c) 2007 Elsevier B.V. All rights reserved.

Adsorption of transition-metal ions in ethanol solution by a nanomaterial based on modified silsesquioxane

The material octakis[3-(3-amino- 1,2,4-triazole)propyl]octasilsesquioxane (ATZ-SSQ) was synthesized and its potential was assessed for Cu(II), Ni(II), Co(II), Zn(II) and Fe(III) from their ethanol solutions and compared with related 3-amino-1,2,4-triazole-propyl modified silica gel (ATZ-SG). The adsorption was performed using a batchwise process and both organofunctionalized surfaces showed the ability to adsorb the metal ions from ethanol solution. The Langmuir model allowed to describe the sorption of the metal ions on ATZ-SSQ and ATTZ-SG in a satisfactory way. The equilibrium is reached very quickly Q min) for ATZ-SSQ, indicating that the adsorption sites are well exposed. The maximum metal ion uptake values for Cu(II), Co(II), Zn(II), Ni(II) and Fe(III) were 0.86, 0.09, 0.19, 0.09 and 0.10 mmol g(-1), respectively, for the ATZ-SSQ, which were higher than the corresponding values 0.21, 0.04, 0.14, 0.05 and 0.07 mmol g(-1) achieved with the ATZ-SG. In order to obtain more information on the metal-ligand interaction of the complexes on the surface of the ATZ-SSQ, Cu(II) was used as a probe to determine the arrangements of the ligands around the central metal ion by electron spin resonance (ESR). The ATZ-SSQ was used for the separation and determination (in flow using a column technique) of the metal ions present in commercial ethanol. (c) 2008 Elsevier B.V. All rights reserved.

DNA - novel nanomaterial for applications in photonics and in electronics

Functionalization with surfactants and with active molecules of deoxyribonucleic acid (DNA), thin film processing as well as their nonlinear optical and electrical properties are reviewed and discussed. On the basis of a quantum three level model, we show that the anomalous concentration variation of cubic susceptibility chi((3))(-3 omega; omega, omega, omega) in thin films of DNA-CTMA complexes doped with Disperse Red 1 chromophore can be explained by the concentration variation of two-photon resonance contribution. We show also that the DNA complexes, plasticized with glycerol and adequately doped can be processed into self standing conducting membranes with a high electrical conductivity. The measured ionic conductivity at room temperature, depending on dopant used and its concentration, is in the range of 3.5 x 10(-4)-10(-5) S/cm and increases linearly as a function of temperature, reaching 10(-3) S/cm at 358 K for the most conducting sample, obeying predominantly the Arrhenius law. Practical applications of DNA complexes are also described and discussed. (C) 2012 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Efeitos bioquímicos da exposição ao nanomaterial óxido de grafeno em diferentes tecidos do camarão branco (Litopenaeus vannamei; Crustacea, Decapoda), através da suplementação na ração

O desenvolvimento da nanotecnologia vem se intensificando nos últimos anos. Sendo que os NM já estão sendo utilizados em vários produtos disponíveis no mercado. Dentre os NM mais utilizados estão os compostos de carbono que embora sejam compostos somente por este elemento podem ter estruturas diferentes que refletem em suas aplicações e possivelmente em seus efeitos. Dentre os NM de carbono, o grafeno e o óxido de grafeno apresentam promissoras características que ampliam sua utilização em diversos segmentos desde eletrônicos até a distribuição de medicamentos. A intensificação da produção e utilização destes NM é acompanhada pela liberação destes nanomateriais no ambiente que pode afetar os organismos vivos, principalmente os animais aquáticos. Entretanto, pouco se sabe sobre os efeitos do óxido de grafeno em crustáceos de importância comercial como é o caso do camarão branco Litopenaeus vannamei. Portanto, a presente dissertação teve como objetivo avaliar os efeitos biológicos da exposição ao óxido de grafeno em diferentes tecidos do camarão.

Interação da cianotoxina microcistina e o nanomaterial de carbono fulereno (C60) em brânquias do peixe Cyprinus carpio (Teleostei: Cyprinidae) sob incidência de radiação UVA

A produção mundial de nanomateriais tem aumentado nos últimos anos, em função de suas variadas aplicações tecnológicas e, como consequência do seu crescente uso e demanda, poderão existir riscos ambientais sendo a água o ambiente onde muitas destas substâncias podem exercer efeitos deletérios. Um dos nanomaterias de carbono mais utilizados é o fulereno, um composto orgânico lipofílico que pode se comportar como carreador de moléculas tóxicas, potencializando a entrada de contaminantes ambientais em órgãos específicos, fenômeno conhecido como “cavalo de Troia”. As microcistinas (MC) são cianotoxinas produzidas por cianobactérias durante episódios de floração, afetando aos organismos aquáticos e ao ser humano. Diversos estudos demonstram que organismos expostos tanto às MCs quanto ao fulereno podem causar produção excessiva de espécies ativas de oxigênio e alterar os níveis de antioxidantes. Além disso, outro fator que pode vir a intensificar o potencial tóxico de ambos é a incidência de radiação UVA. Sendo assim, procurou-se avaliar os efeitos em parâmetros de estresse oxidativo da co-exposição ex vivo da cianotoxina microcistina-LR (MC-LR) e o nanomaterial de carbono fulereno em brânquias do peixe Cyprinus carpio sob incidência de radiação UVA. Os resultados mostraram que: (a) houve uma perda da capacidade antioxidante no tratamento com MC-LR (baixa concentração) quando coexposta com fulereno no UVA em relação com o tratamento realizado sem co-exposição com fulereno; (b) o fulereno no UV diminuiu a atividade da enzima glutationa-Stransferase (GST) quando comparado com o controle no UV; (c) a MC-LR (alta concentração) co-exposta com fulereno foi capaz de diminuir as concentrações do antioxidante glutationa (GSH) quando comparado com o mesmo tratamento tanto no UVA quanto no escuro sem a co-exposição ao fulereno; (d) o tratamento MC-LR (baixa concentração) com UVA aumentou o dano oxidativo lipídico quando comparado com o controle UVA; (e) o fulereno não causou uma maior bioacumulação da microcistina no tecido. Sendo assim, pode-se concluir que o fulereno não apresentou o potencial de carregador de moléculas nessas concentrações de microcistina, porém, a co-exposição dos compostos diminuem tanto capacidade antioxidante total, como a concentração da GSH, podendo gerar problemas a longo prazo na detoxificação da toxina.

Dielectric studies of Liquid Crystal Nanocomposites and Nanomaterial systems.

Liquid crystals (LCs) have revolutionized the display and communication technologies. Doping of LCs with inorganic nanoparticles such as carbon nanotubes, gold nanoparticles and ferroelectric nanoparticles have garnered the interest of research community as they aid in improving the electro-optic performance. In this thesis, we examine a hybrid nanocomposite comprising of 5CB liquid crystal and block copolymer functionalized barium titanate ferroelectric nanoparticles. This hybrid system exhibits a giant soft-memory effect. Here, spontaneous polarization of ferroelectric nanoparticles couples synergistically with the radially aligned BCP chains to create nanoscopic domains that can be rotated electromechanically and locked in space even after the removal of the applied electric field. The resulting non-volatile memory is several times larger than the non-functionalized sample and provides an insight into the role of non-covalent polymer functionalization. We also present the latest results from the dielectric and spectroscopic study of field assisted alignment of gold nanorods.

Influência dos ácidos graxos do tipo ômega-3 ou ômega-6 e o nanomaterial de carbono fulereno (C60) no estado antioxidante em suspensões celulares de cérebro de Cyprinus carpio (Pisces, Cyprinidae)

Os nanomateriais de carbono como o fulereno (C60) apresenta comportamentos bioquímicos distintos, podendo atuar como antioxidante ou pró-oxidante em diferentes sistemas biológicos. Outra evidência ao C60 refere-se a sua característica lipofilica, na qual oferece ação mais direta a diferentes tipos de membranas celulares. Do mesmo modo ácidos graxos poliinsaturados (AGPs) como o ômega-3 (DHA) e o ômega-6 (LA) são importantes para funções celulares da membrana, sendo considerados antioxidantes clássicos. Dessa forma este estudo avaliou em suspensões celulares de cérebro da carpa (Cyprinus carpio, Cyprinidae), o efeito de C60 após um pré-tratamento com DHA ou LA. Para tal avaliação os ensaios consistiram em um pré-tratamento com AGPs (48h) e após exposição a C60 (2h). Como resultados observamos que a viabilidade celular e a capacidade antioxidante total não apresentaram diferença (p> 0.05) entre todos os grupos. Em relação a valores de espécies ativas de oxigênio e dano lipídico foi observado redução nos seus valores nos grupos expostos ao C60 pré – tratados com AGPs (p<0.05). Em termos de cisteína, ocorre uma redução da sua concentração em todos os grupos expostos ao C60. Porém para glutationa a exposição ao C60 provoca um aumento de sua concentração nos grupo controle (sem AGPs) e no grupo pré – tratado com DHA. Dessa forma consideramos que o pré – tratamento com AGPs é benéfico às células, uma vez que um aumento nos níveis de glutationa e uma diminuição na concentração de espécies ativas de oxigênio e peroxidação lipídica foram observados nos grupos expostos ao C60. Sendo assim um bom estado nutritivo em termos da concentração de AGPs foi considerado benéfico na exposição ao fulereno.

Non-Equilibrium Atmospheric Plasma As A Novel Route To Nanomaterial Synthesis And Processing For Biomedical Applications

Since last century, the rising interest of value-added and advanced functional materials has spurred a ceaseless development in terms of industrial processes and applications. Among the emerging technologies, thanks to their unique features and versatility in terms of supported processes, non-equilibrium plasma discharges appear as a key solvent-free, high-throughput and cost-efficient technique. Nevertheless, applied research studies are needed with the aim of addressing plasma potentialities optimizing devices and processes for future industrial applications. In this framework, the aim of this dissertation is to report on the activities carried out and the results achieved concerning the development and optimization of plasma techniques for nanomaterial synthesis and processing to be applied in the biomedical field. In the first section, the design and investigation of a plasma assisted process for the production of silver (Ag) nanostructured multilayer coatings exhibiting anti-biofilm and anti-clot properties is described. With the aim on enabling in-situ and on-demand deposition of Ag nanoparticles (NPs), the optimization of a continuous in-flight aerosol process for particle synthesis is reported. The stability and promising biological performances of deposited coatings spurred further investigation through in-vitro and in-vivo tests which results are reported and discussed. With the aim of addressing the unanswered questions and tuning NPs functionalities, the second section concerns the study of silver containing droplet conversion in a flow-through plasma reactor. The presented results, obtained combining different analysis techniques, support a formation mechanism based on droplet to particle conversion driven by plasma induced precursor reduction. Finally, the third section deals with the development of a simulative and experimental approach used to investigate the in-situ droplet evaporation inside the plasma discharge addressing the main contributions to liquid evaporation in the perspective of process industrial scale up.