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sexta-feira, 17 de maio de 2013

The Big Risk of Small Particles: The Threats and Promise of Nanotechnology


nanotech
Skin cancer is reaching epidemic proportions in Australia. A combination of long, blistering summers and increased exposure to ultraviolet radiation from the depletion of the ozone layer has pushed up the number of sufferers. Health-care providers delivered over 412,000 treatments for non-melanoma cancer in 1997. In 2010, that figure hit 767,000, the Australian Medical Journal reported last year. By 2015, treatments are likely to top 900,000. The graphs for melanoma cancer are also trending upwards.
Not surprisingly, sunscreens are high on the list of defenses among a nation that prides itself on an outdoor lifestyle. But now some Australians would prefer to go without that protection because of a novel ingredient manufacturers are adding to their creams: nanotechnology.
Industry studies say replacing traditional “bulk” zinc oxide products, which filter UV radiation, with their nano counterparts makes sunscreen both transparent and more effective. The health risk is negligible, they say. In fact, well-publicized research conducted in 2010 by Australia’s science agency CSIRO said that sunbathers using nano-enhanced sunscreens might even enjoy health benefits from marginally increased zinc levels.
BIG RISK OF SMALL PARTICLES
The safety concerns surrounding nanotechnology have eased since the early debates focused on science fiction fears, butNANOTECH’S TROUBLED PASTremains relevant to today’s climate.
But Australians have been hard to convince. And many non-governmental organizations (NGOs) have sided with the skeptics. Last year, for example, Friends of the Earth, an international network of environmental activist groups, called for stronger regulation, clear product labelling and other measures that would effectively ban the use of nano applications from sunscreens. The document (“Nano ingredients in sunscreen, the need for regulation”) cited research that suggested nano zinc oxide could increase cancer risk for users and, worse still, cause damage to DNA.
“Until risk assessment for nanomaterials is validated and fit-for-purpose detection methods are developed, we do not support the commercial sale of nano-sunscreens,” said Georgia Miller, the author of the report.
There have been similar arguments about nanotechnology in other fields. Five years ago, it was nanosilver. In 2008, an alliance of health and environmental campaigners filed a petition with the U.S. Environmental Protection Agency (EPA) against manufacturers of nanosilver products. It argued that the substance, which is used in washing machines, among other things, could increase the toxicity of waterways.
Before that, it was carbon nanotubes, which are used in medical equipment, building materials, sporting goods and vehicles but may also have the potential to cause cancer. And in 2003, the U.S. Congress became embroiled in a bitter fight about the definition, uses and risks associated with such technologies. Everywhere it is found, this tiny technology seems to cause trouble.
New Risks, New Rules
Nanotechnology refers to the study and application of materials at the atomic and molecular level, specifically anything smaller than 100 nanometers. (A nanometer is one-billionth of a meter—to put this in perspective, a sheet of paper is about 100,000 nanometers thick.) One of the reasons that the risks and benefits of nanotechnology are so hard to pin down is that it does not exist as a single thing. Calling them “nanotechnologies” would be more accurate.
Scientists often have to rip up the rule book on toxicology when dealing with nanotech.
Modern engineering techniques often work at the atomic level, so when products hit the supermarket shelves or enter the industrial supply chain, they are nanotechnologies by default. Those manufacturing processes cut across all sectors—from medicine, computing and cosmetics to energy, plastics and electronics. Sometimes, scientists working on the same product call it by different names because the processes are so new that they may be working in ignorance of each other’s research.
Risk is also difficult to assess because many nanomaterials act in unique ways. Nanosilver, for example, has a much higher surface area than traditional forms of the metal. That makes it excellent as an anti-viral material, and some hospital surfaces have nanosilver particles built into them to help fight superbugs. But the bigger surface area increases its toxicity when it comes into contact with the environment.
Scientists often have to rip up the rule book on toxicology when dealing with nanotech. Only recently have they begun to develop more standardized ways of assessing their potential risks.
In the middle of last year, the standard-setting International Organization for Standardization (ISO) published voluntary guidance for researchers on this issue (ISO/TR 13014:2012). The publication aimed to help experts “understand, plan, identify and address relevant physicochemical characteristics of nano-objects before conducting toxicological tests on them.”
The document is an admission that the traditional approaches did not work because they took no account of the physical aspects of materials. “The old way in toxicology is to think of how much mass there is and work out how harmful it might be,” said Richard Pleus, chair for the report and a member of the ISO technical group that oversees standards on nanotechnologies. “Nanotechnology helped us understand that the surface area of a substance could also influence its toxicity.”
Pleus expects the standard to help with the overall quality of scientific research on hazards, which he admits still needs improvement. That is because more information on each nanomaterial should help to make experiments on them comparable. But these in-depth tests are time-consuming and expensive, and the number of toxicologists in the world is finite. The UK’s Royal Commission on Environmental Pollution warned in 2008 that it would take decades to carry out enough research to produce reliable data that could inform effective regulation.
“Without social acceptance, we can’t sell our products.”  – Carolin Kranz of BASF
But industry does not wait. The global market for nanotechnology is growing at almost 20% per year. In 2011, it was worth just over $20 billion, according to the forecasting firm BCC Research. It expects total sales to reach almost $50 billion by 2017.
Lux Research puts global sales even higher. It estimates that if the figures are adjusted to include the sales from so-called composite products, in which nanoscale and larger materials are mixed, the value of the market will reach almost $2.4 trillion in 2015. These are big figures for such small particles.
Regulating in a Vacuum
Given the speed of this growth, regulators initially have had to act in a relative data vacuum regarding potential risks. Different countries have taken different routes. U.S. authorities, for example, do not recognize nanotechnology as a distinctive substance that needs its own definition and separate regulator.
Instead, existing bodies manage applications. The EPA, for example, deals with nanosilver when used as a pesticide; the U.S. Food and Drug Administration deals with nanosilver when it is used as a wound dressing.
The White House’s Emerging Technologies Interagency Policy Coordination Committee published a memorandum on regulating nanotechnology in 2011. The document lists a set of principles for regulators to consider and calls for more coordination between agencies. But it does not specifically define nanotechnology and argues that any judgement on whether nanomaterials are benign or harmful needs to be based on scientific evidence. Gathering data has become a major focus.
Chemical manufacturing in Europe, on the other hand, is regulated under the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), an EU regulation that has been in force since June 2007. Now, any chemical imported into, or manufactured in, the European Union in quantities of more than one ton per year must be registered with REACH. If they aren’t, they may not be made or sold within EU borders. While REACH only talks of chemical substances, the European Commission adopted a definition of nanotechnology in 2011 that will underpin all of its regulation of nanomaterials.
Industry experts generally believe that the U.S. system will be more resilient in managing existing and emerging risks in the field. “I think the U.S. regulators are able to handle any risk issues that arise on nanotechnologies,” said Martha Marrapese, partner at the U.S. law firm Keller and Heckman and founder of the practice’s special interest group in nanotechnology. She says that they have a track record in reviewing materials and have chosen to regulate nanomaterials based on whatever scientific evidence they have seen.
U.S. regulators have powers to request more data and deny the release of materials about which they have concerns. They can also fine companies for infringements, such as using false descriptions on their products. Beyond the field of pesticides, however, there has been very little enforcement from the regulators in terms of fines. “Agencies have used those few cases to send out a clear message,” said Marrapese. “Be aware of the programs, and register your products.”
“I think the U.S. regulators are able to handle any risk issues that arise on nanotechnologies.” – Martha Marrapese, partner at Keller and Heckman
Searching for an Advocate
Andrew Maynard says that Europe’s more-prescriptive view could see some risky, novel materials, which may be larger than 100 nanometers, fall outside of its regulatory framework. And on the whole, Maynard, international chair of environmental health sciences at the University of Michigan, believes that regulators are behind the game when it comes to the more-complex materials now emerging.
Despite the recent ISO standard, he says that U.S. administrators still view risk from the old chemical paradigm and pay much less attention to the potential hazards created by the physical properties of sophisticated materials. These issues have been compounded, he argues, by the way that the industry has been “slow off the mark” to deal with risk and in devising suitable toxicology tests.
“There is an explosion of research in this area,” he said, “and we are beginning to piece together parts of the puzzle. But it is painfully slow and it doesn’t tell us exactly what we need to know.” He also worries that no one seems willing to champion the benefits of nanotechnologies, which allows public debate to be dominated by cries of their potential harms.
Hilary Sutcliffe, director of Matter, a self-styled emerging technologies “action tank,” lays much of the blame for this at the doorstep of big business. She says companies have failed to sell the benefits of nanotechnologies to the public.
In 2008, Sutcliffe set up the Responsible Nano Forum and, prior to that, was a member of the secretariat for the Responsible Nano Code, a multi-stakeholder initiative that developed a principles-based code of conduct for companies involved with nanotechnologies. The code was intended to act as a benchmark for investors, she says, but it failed to get adequate funding from global corporations. It is now used mainly by the Brussels-based trade body, the Nanotechnologies Industry Association (NIA), help to certify product quality and safety.
“We felt, with the Nano Code, that we were communicating into a vacuum, and ultimately people got too frightened to identify themselves with nanotechnology,” she said.
No one seems willing to champion the benefits of nanotechnologies, which allows public debate to be dominated by cries of their potential harms.
Instead of being driven by the debates around risk and harm, Sutcliffe argues that corporations need to build trust with the public by being open and talking in a measured way about the benefits and risks associated with their products. “You can’t do research all the time because it leads to analysis-paralysis,” she said. “You need to get your products in front of people and talk about them.”
Opening a Nanotech Dialogue
There are few takers. But one of them is the world’s largest chemicals company, BASF. The German-based corporation has been running its Dialog Forum Nano since 2008. It says it has found the process useful.
The project gets a wide range of stakeholders together, including representatives from science, labor unions, commercial and business interests, churches, and environmental and consumer groups, to discuss the company’s products in specific sectors. Policymakers are specifically excluded so that no one attending the sessions is tempted to turn meetings into a soapbox for political advocacy.
“The initiative is part of the company’s risk management of nanotechnology,” said Carolin Kranz, BASF’s senior manager of communications and government relations. Other strands of its risk processes include safety research and political communication, but the Dialog is high on the company’s list of priorities. “Without social acceptance, we can’t sell our products,” she said.
The program does not deal directly with the public but relies on the participants to communicate with their own stakeholders, including the wider population. “Of course, we cannot know what the stakeholders will make of it,” she said.
But it is a risk the company believes is worth taking. Not only does BASF have the opportunity to get its message across and educate the participants, the process acts as an early-warning system. Kranz says that if anyone in the group does not accept nanotechnology in a particular product, that information is fed back into the company and informs its decision making.
While the Dialog initiative has been successful in Kranz’s view, it has also been a challenge. She feels that the company has too many audiences to persuade, each with its own level of technical competence. On top of that, each audience is likely to have its own interests and agendas that it wants to communicate to the corporation. That can be a lot for the company to take on board.
Given the prevailing public ignorance and uncertainty about nanotechnologies and the over-riding focus on hazards in some products, the industry trade body NIA wants to see more government action.
More Government Action Required
Given the prevailing public ignorance and uncertainty about nanotechnologies and the over-riding focus on hazards in some products, the industry trade body NIA wants to see more government action.
“While industries always take the lion’s share of responsibility for communicating the benefits of their products on the market,” said Steffi Friedrichs, NIA’s managing director, “the current risk-centric debates on nanomaterials have also created a strong responsibility for governments to wade in and support nanotechnology’s innovative power. It should ultimately provide an unbiased environment, in which the benefits can be openly communicated.”
For Australians facing more scorching summers, an unbiased assessment of the sunscreen products they use cannot come soon enough. But with the continuing lack of clarity over the risks and benefits of nanotechnologies in so many areas, it could be a long wait. Until then, the threat of uncertain hazards will continue to hover over the entire industry.

quarta-feira, 15 de maio de 2013

Charting Europe's nanotechnology 'roadmap'


Nanotechnology is opening the way to a new industrial revolution. From 'individualised' medical treatments tailored for each patient to new, environmentally-friendly energy storage and generation systems, nanotechnology is bringing significant advances. Exciting new futures await those businesses able to get ahead in the race to turn this wealth of promise into commercial success. But in a field which requires a high degree of coordinated effort involving many different stakeholder groups, including researchers, policymakers and commercial players across a wide variety of industrial sectors, it has perhaps been inevitable that fragmentation, disconnectedness and duplication have stood in the way.

NANOfutures was set up in 2010 to tackle exactly this problem of fragmentation. Supported by European Union (EU) funding, NANOfutures is a European Technology and Innovation Platform (ETIP) bringing together industry, research institutions and universities, NGOs, financial institutions, civil society and policymakers at regional, national and European levels. Acting as a kind of ‘nano-hub’ for Europe, NANOfutures is dedicated to fostering a shared vision and strategy on the future of nanotechnology. 

Reflecting its objective of achieving a truly cross-sectoral approach, breaking out of individual industry silos and addressing the major nanotech issues which are common to all sectors, NANOfutures set up a steering committee which included representatives from 11 European Technology Platforms (ETPs) - sector-specific networks of industry and academia - including those for textiles, nanomedicine, construction and transportation. Chaired by Professor Paolo Matteazzi of Italian specialist nanomaterials company MBN Nanomaterialia, the committee also included ten nanotechnology experts, each one chairing a NANOfutures working group on cross-sectoral topics such as safety, standardisation, regulation, technology transfer and innovative financing. 

This approach allowed NANOfutures to identify key aspects of nanotechnology and its exploitation in which all players - from researcher to politician, financier, commercial developer, regulator or end-user - were involved and therefore had common interests. 
One of the major successes achieved by the two-year project was securing an agreement by all 11 ETPs on a set of research and innovation themes for the next decade. “The ETPs agreed to focus their private efforts, and call for increasing public efforts, on such themes in order to bring European nano-enabled products to successful commercialisation, with benefits for the grand challenges of our time such as climate change, affordable and effective medicine, green mobility and manufacturing,” says the project’s coordinator, Margherita Cioffi of Italian engineering consultancy D’Appolonia.

The most tangible result of this, and the key outcome from NANOfutures, was the development and publication of a ‘Research and Industrial Roadmap’ setting out, in Ms Cioffi’s words, “a pathway up to 2020 which will enable European industry and researchers to deliver and successfully commercialise sustainable and safe nano-enabled products.” Divided into seven separate thematic areas, or ‘value-chains’, the roadmap covers European priorities from materials research to product design, manufacturing, assembly, use and disposal. It describes both short- and longer-term actions with the aim of providing a practical guide for EC and Member State governments, research centres and industry, as well as standardisation and regulation bodies.

Other benefits directly resulting from the project, Ms Cioffi adds, were the sharing of safety best practices, the creation of partnerships to promote product development, training and other services, and the bringing together of relevant SME businesses with potential users and investors during specially organised Technology Transfer workshops.

Since it is not a product in itself, but a method with an enormous range of potential applications, nanotechnology naturally reaches into a diverse range of human activities. Paradoxically, almost, this very richness and universality of its benefits leads to a fragmentation of effort which acts as a barrier to its efficient exploitation. By bringing together the various stakeholders to create a unified, strategic approach, replacing fragmentation and duplication with a focus on areas of agreed priority and common interest, NANOfutures has played an invaluable role in promoting the rapid development of nanotechnology - with its twin benefits of societal usefulness and enhanced European competitiveness. 


Project details
  • Project acronym: NANOFUTURES
  • Participants: Italy (Coordinator), Belgium, Spain
  • Project FP7 266789
  • Total costs: €1 171 011
  • EU contribution: €999 980
  • Duration: October 2010 - September 2012


Fonte: European Commission

Characterization and Control of Occupational Exposure to Nanoparticles and Ultrafine Particles

Debia, Maximilien; Beaudry, Charles; Weichenthal, Scott; Tardif, Robert; Dufresne, André
Studies and Research Projects / Report  R-777, Montréal, IRSST, 2013, 66 pages.
Version française disponible : R-746


Free download (PDF 1617 Ko)

Abstract
Many workers are exposed to a range of particles present on a nanometric scale. In occupational hygiene, it is common to differentiate manufactured nanoparticles (NP) from ultrafine particles (UFP) coming from natural, human or industrial sources. Given that major deficiencies exist in the usual risk assessment approaches for these particles, the objective of this research was to assess occupational UFP and NP exposures. The secondary objective was comprehensive testing of the assessment capabilities regarding occupational NP and UFP exposures in an industrial and laboratory context. 
Two main types of assessment were performed during this research. The first concerns the assessment of the fine and ultrafine particle concentrations with a particle counter (P-Trak, model 8525), and the second pertains to the assessment of fine and ultrafine particle size distribution with an electrical low pressure impactor (ELPI). The measurements were taken in two welding schools, an aluminium smelter, the research centre of a thermoplastics processing company, and three university laboratories producing and/or using nanoparticles.

The results revealed that aluminium smelter workers, people who perform welding tasks, and workers in the thermoplastic processing industry are exposed to UFPs. However, the assessments performed under this study do not reveal high NP concentrations in research laboratories. Only NP production by milling generated detectable NP concentrations. NP handling in glove boxes of two other laboratories seems to prevent worker exposure adequately.

There is currently no consensus concerning UFP and NP exposure evaluation measures. However, our findings suggest that the P-Trak is suitable for occupational assessment of UFP concentrations, whereas several uncertainties remain to assess NP exposure, particularly in their agglomerated form. In view of this research, it appears that a characterization and control study of occupational NP and UFP exposure should include assessment of the mass and particle number concentrations, measurement of granulometric distribution and electron microscopic characterization of nanoscale particles.

Fonte: Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST)

terça-feira, 14 de maio de 2013

New study shows overuse of nano-silver could help breed superbugs

Cover image for Vol. 9 Issue 8
Induced Adaptation of Bacillus sp.
to Antimicrobial Nanosilver

Friends of the Earth has renewed its calls for a ban on the use of nano-silver in consumer products, after a new a UNSW study has found that overexposure to silver nanoparticles can cause potentially harmful bacteria to rapidly adapt and flourish
The study, published in the journal Small, found that nano-silver was effective in suppressing some bacteria (such as E. coli), but that its presence initiated the unexpected emergence, adaptation and abnormally fast growth of other bacteria species (in this case, a type of Bacillus bacteria). 
This is the first study that has demonstrated that a widely occurring bacteria can adapt quite rapidly to the antimicrobial action of nano-silver. It raises serious concerns that the widespread use of nano-silver in consumer products could be helping to breed superbugs.
The overuse of antimicrobials by Australians is contributing to a crisis that the World Health Organisation has labelled ‘one of the greatest threats to human health today’.
In Australia more than 7000 deaths each year are caused by bacterial resistance to antimicrobials. It is now widely understood the widespread overuse and misuse of antimicrobials is an important contributor to antimicrobial resistance (AMR) in bacteria.
The medical community has been turning to nano-silver as an antimicrobial of last resort to prevent the infections of superbugs. But at the same time, many companies have seen a marketing advantage in including nano-silver as an ingredient in everyday products such as socks, underpants, toothbrushes and cleaning clothes.
Health experts agree the widespread use of nano-silver in consumer products such as socks and fridges will further increase the problem of superbugs. We should restrict the use of this powerful antimicrobial to hospitals, where it’s needed most.
Senate Inquiry is currently investigating the problem of antimicrobial resistance and is due to report its findings on 24th May.
In response to the Inquiry, a broad coalition of organisations have launched astatement calling for urgent action to tackle the looming antimicrobial resistance (AMR) crisis. The statement, endorsed by the Public Health Association of Australia, Friends of the Earth, The Australia Institute and the National Toxics Network calls for a range of measures including restricting the use of nano-silver to clinical settings.

quarta-feira, 8 de maio de 2013

Manto da invisibilidade é fabricado por impressora 3D

Manto da invisibilidade é fabricado por impressora 3D
O objeto camuflado fica no centro do metamaterial,
que evita que as ondas sejam refletidas por ele, tornando-o invisível.
[Imagem: Duke University]

A lista de objetos que podem ser fabricados usando impressoras 3D parece não ter fim - os exemplos mais recentes incluem uma pistola que atira de verdade e uma orelha biônica.
Os mantos da invisibilidade estão entre os feitos mais recentes da tecnologia: a ideia criar camuflagens usando metamateriais foi lançada há menos de sete anos.
Até agora, a impressão que eles passavam era de se esconderem por trás de uma matemática pesada e de técnicas de fabricação não menos complicadas.
Mas Yaroslav Urzhumov, da Universidade de Duke, nos Estados Unidos, acaba de criar um manto da invisibilidade usando uma impressora 3D comum.
"Eu diria que, essencialmente, quem pode gastar alguns milhares de dólares em uma impressora 3-D comum pode literalmente fazer um manto de invisibilidade de plástico do dia para a noite," disse ele.
Urzhumov é especialista na área de óptica transformacional - a área que deu origem aos metamateriais - tendo entre seus feitos um sistema de invisibilidade aquática para navios e submarinos e um amplificador de campos magnéticos.
Impressão 3D invisível
A impressão tridimensional, tecnicamente conhecida como fabricação aditiva, ou fabricação estereolitográfica, tem-se tornado cada vez mais popular, não só na indústria, mas também para uso pessoal.
Trata-se de um bico guiado por um programa de computador, que deposita sucessivas camadas de um material - geralmente um polímero, mas que também pode ser poeira lunar - até produzir um objeto tridimensional.
Urzhumov disse que fabricar um manto de invisibilidade dessa forma é barato e fácil.
Algoritmos determinam a localização, o tamanho e a forma dos orifícios que desviam as ondas eletromagnéticas. O processo de fabricação leva entre três e sete horas.
Camuflagem óptica
Assim como no caso da camuflagem pioneira de 2006, a versão impressa mais recente também desvia feixes de micro-ondas.
Mas os pesquisadores dizem estar confiantes de que, em um futuro não tão distante, será possível imprimir mantos de invisibilidade para comprimentos de onda maiores, incluindo a luz visível.
"Nós acreditamos que esta abordagem é um caminho rumo à camuflagem óptica, incluindo ondas visíveis e infravermelhas," disse Urzhumov.
"E já há nanotecnologia disponível para fazer estas capas a partir de polímeros transparentes ou vidros. As propriedades dos polímeros transparentes e dos vidros não são muito diferente das que temos em nosso polímero na frequência de micro-ondas," concluiu ele.
O estado da arte em termos de mantos de invisibilidade, contudo, é representando por um manto muito mais fino do que o exemplar fabricado agora por impressão 3D:
Bibliografia:

Thin Low-Loss Dielectric Coatings for Free-Space Cloaking
Yaroslav Urzhumov, Nathan Landy, Tom Driscoll, Dimitri Basov, David R. Smith
Optics Letters
Vol.: 38, Issue 10, pp. 1606-1608
DOI: 10.1364/OL.38.001606


Fonte: Inovação Tecnológica

Demi-journée d'échanges "Les citoyens face aux nanotechnologies: quels défis ?"



Le développement galopant des nanotechnologies et l'arrivée sur le marché de plusieurs centaines de produits de consommation qui en sont issus soulèvent de nombreuses questions. Suspicion de risques sanitaires et environnementaux, questions éthiques, sociales... Autant de sujets dont les citoyens doivent se saisir. Où en est-on trois ans après le débat national sur les nanotechnologies ?
Sciences et Démocratie, en partenariat avec l'Avicenn (veille d'information citoyenne sur les nanotechnologies), propose une demi-journée d'échanges intitulée « Les citoyens face aux nanotechnologies : quels défis ? ». 
L’objectif est de dresser un panorama des évolutions de la société face aux nanotechnologies et de donner des repères pour l’action citoyenne. Cet évènement est le prolongement du travail de réflexion et de débats mené par l'association depuis 2006.
nanobot.png
Programme :
14h30-15h00 - Les nanotechnologies, enjeux de société
Les nanotechnologies : qu'est-ce que c'est, quelles applications aujourd'hui, quelles promesses, quels risques potentiels ?
Intervenant : Philippe Bourlitio (Sciences et Démocratie)
Discussion
15h00-16h00 - La société civile concernée
Tour d'horizon des acteurs mobilisés, des recommandations formulées, des chantiers en cours et des lieux où la société civile peut peser.
Intervenant : Mathilde Detcheverry (Avicenn)
L'exemple du Comité de dialogue « nanomatériaux et santé » de l'Anses : objectifs, modalités de fonctionnement, premiers enseignements, perspectives.
Intervenant : Benoît Vergriette (Anses)
Discussion
16h00-16h10 - Pause
16h10-16h30 - Le nouveau cadre juridique
Intérêts et limites des nouvelles mesures encadrant les nanotechnologies : déclaration obligatoire des substances à l'état nanoparticulaire, étiquetage nano pour les cosmétiques, les biocides, les aliments.
Intervenant : Stéphanie Lacour (Cecoji, CNRS)
Discussion
16h30-17h10 - Et demain, quelles orientations pour l'action citoyenne ?
Quels chantiers engager, poursuivre, abandonner ? Quelles urgences ? Quelle place pour l'information des consommateurs en situation d'incertitudes sur l'innocuité des produits ?
Table ronde animée par Philippe Bourlitio, avec Stéphanie Lacour (Cecoji, CNRS), Simone Cassette (Collectif NanoSaclay), Mathilde Detcheverry(Avicenn), Bertrand Bocquet (Sciences Citoyennes).
17h10-17h20 - Synthèse
par Stéphane L'Hostis, président de Sciences et Démocratie
Lieu :
CNAM
Accès 17, 2e étage, salle 21.2.23
292 Rue Saint-Martin
75003 Paris
Inscription et renseignements : par mail à contact@sciences-et-democratie.org


Fonte: Sciences et Démocratie

Ubiquitous engineered nanomaterials cause lung inflammation, study finds

Substances are used in everything from paint to sporting equipment



(SACRAMENTO, Calif.) 
A consortium of scientists from across the country has found that breathing ultrafine particles from a large family of materials that increasingly are found in a host of household and commercial products, from sunscreens to the ink in copy machines to super-strong but lightweight sporting equipment, can cause lung inflammation and damage.
Kent Pinkerton
Kent Pinkerton
The research on two of the most common types of engineered nanomaterials is published online today in Environmental Health Perspectives, the journal of the National Institute of Environmental Health Sciences (NIEHS). It is the first multi-institutional study examining the health effects of engineering nanomaterials to replicate and compare findings from different labs across the country.
The study is critical, the researchers said, because of the large quantities of nanomaterials being used in industry, electronics and medicine. Earlier studies had found when nanomaterials are taken into the lungs they can cause inflammation and fibrosis. The unique contribution of the current study is that all members of the consortium were able to show similar findings when similiar concentrations of the materials were introduced into the respiratory system. The findings should provide guidance for creating policy for the safe development of nanotechnology.
This research provides further confirmation that nanomaterials have the potential to cause inflammation and injury to the lungs. Although small amounts of these materials in the lungs do not appear to produce injury, we still must remain vigilant in using care in the diverse applications of these materials in consumer products and foods,” said Kent Pinkerton, a study senior author and the director of the UC Davis Center for Health and the Environment.”
Used for their ability to confer strength and flexibility because of their tubular and spherical structures, the ubiquitous and highly malleable materials may be composed of everything from carbon to gold. The current study examined the health effects of inhaling two types of nanomaterials, those made from forms of titanium dioxide and those made from multi-walled carbon nanotubes, a substance with a tensile strength 100 times stronger than steel.
The study was conducted as part of the NIEHS NanoGo Consortium, which includes researchers at North Carolina State University, UC Davis, East Carolina University, the Health Effects Laboratory of the National Institute for Occupational Safety and Health, the University of Rochester, the University of Washington and the Center for Environmental Implications of Nanotechnology.
The primary concern for exposure to nanomaterials is by inhalation, although dermal, eye and ingestion exposures also may occur during the manufacture and commercial application of these materials in a wide variety of products. The researchers examined responses of the lungs to nanomaterials made from three forms of titanium dioxide and three forms of multi-walled carbon nanotubes in a mouse model.
The study’s other authors are James C. Bonner and Alexia J. Taylor of North Carolina State University; Rona M. Silva of UC Davis; Jared M. Brown and Susana C. Hilderbrand of East Carolina University; Vincent Castranova and Dale Porter of the National Institute for Occupational Safety and Health; Alison Elder and Günter Oberdörster of the University of Rochester; Jack R. Harkema and Lori A. Bramble of Michigan State University; and Terrance J. Kavanagh and Dianne Botta of the University of Washington and Andre Nel the California Nanosystems Institute.
The research was funded by NIEHS grants RC2 ES018772 (JCB), RO1 ES019311 (JMB), RC2 ES018741 (AE, GO), R01 ES016189 (TJK), P30 ES007033 (TJK), and RC1 ES018232 (KEP).
The UC Davis School of Medicine is among the nation's leading medical schools, recognized for its research and primary-care programs. The school offers fully accredited master's degree programs in public health and in informatics, and its combined M.D.-Ph.D. program is training the next generation of physician-scientists to conduct high-impact research and translate discoveries into better clinical care. Along with being a recognized leader in medical research, the school is committed to serving underserved communities and advancing rural health. For more information, visit UC Davis School of Medicine at medschool.ucdavis.edu.

sexta-feira, 3 de maio de 2013

Injectable nanonetwork controls blood sugar in diabetics

The nanonetwork releases insulin in response to changes in blood sugar.
The nanonetwork releases insulin in
response to changes in blood sugar.

In a promising development for diabetes treatment, researchers have developed a network of nanoscale particles that can be injected into the body and release insulin when blood-sugar levels rise, maintaining normal blood sugar levels for more than a week in animal-based laboratory tests. The work was done by researchers at North Carolina State University, the University of North Carolina at Chapel Hill, the Massachusetts Institute of Technology, and Children’s Hospital Boston.
“We’ve created a ‘smart’ system that is injected into the body and responds to changes in blood sugar by releasing insulin, effectively controlling blood-sugar levels,” says Zhen Gu, lead author of a paper describing the work and an assistant professor in the joint biomedical engineering program at NC State and UNC Chapel Hill. “We’ve tested the technology in mice, and one injection was able to maintain blood sugar levels in the normal range for up to 10 days.”
When a patient has type 1 diabetes, his or her body does not produce sufficient insulin, a hormone that transports glucose—or blood sugar—from the bloodstream into the body’s cells. This can cause a host of health effects. Currently, diabetes patients must take frequent blood samples to monitor their blood-sugar levels and inject insulin as needed to ensure their blood sugar levels are in the “normal” range. However, these injections can be painful, and it can be difficult to determine the accurate dose level of insulin. Administering too much or too little insulin poses its own health risks.
The new, injectable nanonetwork is composed of a mixture containing nanoparticles with a solid core of insulin, modified dextran, and glucose oxidase enzymes. When the enzymes are exposed to high glucose levels they effectively convert glucose into gluconic acid, which breaks down the modified dextran and releases the insulin. The insulin then brings the glucose levels under control. The gluconic acid and dextran are fully biocompatible and dissolve in the body.
Each of these nanoparticle cores is given either a positively charged or negatively charged biocompatible coating. The positively charged coatings are made of chitosan (a material normally found in shrimp shells), while the negatively charged coatings are made of alginate (a material normally found in seaweed).
When the solution of coated nanoparticles is mixed together, the positively and negatively charged coatings are attracted to each other to form a “nanonetwork.” Once injected into the subcutaneous layer of the skin, the nanonetwork holds the nanoparticles together and prevents them from dispersing throughout the body. Both the nanonetwork and the coatings are porous, allowing blood—and blood sugar—to reach the nanoparticle cores.
“This technology effectively creates a ‘closed-loop’ system that mimics the activity of the pancreas in a healthy person, releasing insulin in response to glucose level changes,” Gu says. “This has the potential to improve the health and quality of life of diabetes patients.”
Gu’s research team is currently in discussions to move the technology into clinical trials for use in humans.
The paper was published online in ACS Nano.
Fonte: R&D

Erfolgreiche Forschungsstrategie zur Nanotechnologie schützt Mensch und Umwelt


Bundesbehörden bilanzieren Forschungsprojekte zur Sicherheit von Nanomaterialien

Gemeinsame Pressemitteilung von BAuA, BfR, UBA, BAM und PTB

Die Nanotechnologie gilt als die Fortschrittstechnologie des 21. Jahrhunderts. Sie ist hoch innovativ und dynamisch und eröffnet neue Chancen, Ressourcen zu schonen und Energie zu sparen. Aber wie bei jeder neuen Technologie werfen ihre potenziellen Auswirkungen auf die Umwelt und die Gesundheit von Verbrauchern und Beschäftigten viele Fragen auf. 

Um die mit Nanomaterialien verbundenen offenen Fragen beantworten und ihre Chancen und Risiken gegeneinander abwägen zu können, haben die Bundesanstalt für Arbeitsschutz und Arbeitsmedizin (BAuA), das Bundesinstitut für Risikobewertung (BfR) und das Umweltbundesamt (UBA) bereits im Jahr 2007 eine Forschungsstrategie erarbeitet, in deren Fortschreibung und Entwicklung auch die Physikalisch-Technische Bundesanstalt (PTB) und die BAM Bundesanstalt für Materialforschung und -prüfung eingebunden wurden. 

Jetzt liegt die erste Bilanz vor, für die der Stand von über 80 Forschungsprojekten zu Chancen und Risikoaspekten der Nanotechnologie unter die Lupe genommen wurde. 
Erfolge lassen sich unter anderem bei der Entwicklung von Mess- und Testverfahren, der Ermittlung von Belastungen für Mensch und Umwelt sowie bei der Bewertung von Risiken verbuchen.

Mit der gemeinsamen Forschungsstrategie bündeln die beteiligten Bundesbehörden ihre Ressourcen für den notwendigen Brückenschlag zwischen der Innovationskraft neuer Technologien und der Sicherheit von Mensch und Umwelt. Durch eine strukturierte Zusammenarbeit sollen Risiken neuer Technologien bereits in einem frühen Entwicklungsstadium erkannt und bewertet werden – als Grundlage für die Politikberatung und die Entwicklung praxisgerechter Lösungen.

Im Blickpunkt der öffentlichen Diskussion stehen mögliche Risiken von Nanomaterialien. Die 2007 von den Bundesoberbehörden formulierte Forschungsstrategie benennt offene Forschungsfragen und setzt Prioritäten. Hervorgehoben wurden vor allem Fragen einer Charakterisierung von Nanomaterialien hinsichtlich Gestalt und Zusammensetzung, des Erkennens schädlicher Eigenschaften und zu Methoden zur Ermittlung von Belastungen von Mensch und Umwelt mit aus Nanomaterialien freigesetzten Partikeln. 

Darüber hinaus beschreibt die Forschungsstrategie Voraussetzungen, unter denen Risiken, die mit Nanomaterialien verbunden sein könnten, bewertet werden können und formuliert Leitlinien für ein erfolgreiches Risikomanagement und die zugehörige Risikokommunikation.

In der nun vorgelegten Bilanz werden der Stand und die wichtigsten Ergebnisse von 85 Forschungsprojekten zusammengestellt, die durch die gemeinsame Forschungsstrategie angestoßen oder begleitet wurden. Die Ergebnisse belegen eine große Vielschichtigkeit der Fragestellungen, ermöglichen aber auch eine erste Eingrenzung von Risikoschwerpunkten. Die zukünftige Forschung soll dazu beitragen, aufwändige Untersuchungen vieler einzelner Nanomaterialien zu vermeiden und trotzdem belastbare Aussagen zum Schutz von Beschäftigten, Verbrauchern und Umwelt abzuleiten.

Die 125 Seiten starke erste Bilanz zur gemeinsamen Forschungsstrategie der Ressortforschungseinrichtungen des Bundes „Nanotechnologie – Gesundheits- und Umweltrisiken von Nanomaterialien“ kann von den Internetseiten der Bundesbehörden heruntergeladen oder über die Seiten des BMU (Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit) bezogen werden.

Am 30. April 2013 soll die Bilanzierung der interessierten Öffentlichkeit im BMU, Berlin, vorgestellt werden. Aufgrund der begrenzten Platzzahl ist eine Anmeldung per E-Mail an patricia.adolf@bmu.bund.de erforderlich.

Bilanz „Nanotechnologie – Gesundheits- und Umweltrisiken von Nanomaterialien“ als Download beim UBA:
http://www.umweltbundesamt.de/chemikalien/publikationen/gesundheits_und_umweltrisiken_nanomaterialien.pdf


Nanopartículas de ouro podem fazer mal à saúde

Nanopartículas de ouro podem fazer mal à saúde
Além de usadas em cosméticos e produtos de uso
pessoal, as nanopartículas estão sendo
pesquisadas para transportar
medicamentos no corpo humano.
[Imagem: Cortesia de Hannu Hakkinen]

As nanopartículas são a face mais pesquisada no campo da nanotecnologia voltada à saúde.
Seu principal uso é como carreador de medicamentos, levando as moléculas das drogas diretamente ao local do tratamento, de forma a otimizar os resultados e diminuir os efeitos colaterais.
E, quando se fala de nanopartículas, as consideradas melhores são as de ouro, porque o ouro é inerte e, aparentemente, não faz qualquer mal à saúde humana.
Mas esse pressuposto acaba de ser contestado por um grupo de cientistas da Universidade de Stony Brooks (EUA).
Segundo eles, as nanopartículas de ouro puro, que também já são usadas em produtos de uso pessoal e cosméticos, diminuem o ritmo do processo de cicatrização, aceleram a formação de rugas e inibem o armazenamento de gordura.
As nanopartículas de ouro também são usadas como agentes de contraste em exames de ressonância magnética.
Danos da nanopartículas às células
Para realizar o estudo publicado na revista Nanotoxicology, os pesquisadores testaram o impacto das nanopartículas em culturas de vários tipos de células, incluindo tecido adiposo (gordura), para determinar se as suas funções básicas seriam interrompidas quando expostas a doses de nanopartículas muito baixas.
Nesse caso o acúmulo de gordura referido pelos pesquisadores não tem a ver com a obesidade, mas com a formação do tecido adiposo normal, que protege o corpo do calor e do frio, funciona como uma reserva de nutrientes e serve como uma espécie de amortecedor em órgãos internos.
Os cientistas descobriram que as nanopartículas de ouro entram quase que instantaneamente nas células do estroma derivadas do tecido adiposo humano - um tipo de célula-tronco adulta - e que as nanopartículas se acumulam nas células sem que exista uma via óbvia para sua eliminação.
A presença das nanopartículas interrompeu várias funções celulares, incluindo o movimento, a replicação (divisão celular) e a contração do colágeno, todos processos que são essenciais na cicatrização de ferimentos.
A inibição da contração do colágeno também pode acelerar o processo de formação de rugas na pele.
Além disso, as nanopartículas de ouro puro interferem com a regulação genética, com a expressão do RNA e inibem a capacidade de diferenciação dos adipócitos, as células de gordura adultas.
"Reduções causadas pelas nanopartículas de ouro podem resultar em mudanças sistêmicas para o corpo," disse Tatsiana Mironava, coordenadora do estudo.
Riscos das nanopartículas
"Como [as nanopartículas de ouro] vinham sendo consideradas inertes e essencialmente inofensivas, assumiu-se que as nanopartículas de ouro puro seriam também seguras. As provas em contrário estão começando a emergir," concluiu a pesquisadora.
De fato, vários estudos têm levantado alertas sobre os riscos potenciais das nanopartículas à saúde humana, o que levou a Organização Mundial da Saúde a começar a mapear os riscos da Nanotecnologia:


Fonte: Diário da Saúde