Silver nanoparticles can now be found in all kinds of products, from socks to food containers to coatings for medical devices. Valued for its infection-fighting, antimicrobial properties, silver, in its modern incarnation as silver nanoparticles, has become the promising antimicrobial material in a variety of applications because the nanoparticles can damage bacterial cells. Due to their plasmonic properties and easy surface chemistry silver nanoparticles are also beginning to attract interest among nanomedicine researchers. However, the surface chemistry of nanoparticles that governs their interactions with other constituents in their environment has critical importance. Therefore, chemically altering the surface properties of nanoparticles with polymers, biological ligands and macromolecules is actively being explored.
Some scientists believe that, with the increased mass production of engineered nanoparticles like carbon nanotubes, there is a realistic chance for these particles to interact with water, soil and air, and subsequently enter the food chain. However, understanding the behavior and impacts of nanomaterials in the environment and in human health is a daunting task. Nevertheless, a general understanding about nanotoxicity is slowly emerging as the body of research on cytotoxicity, genotoxicity, and ecotoxicity of nanomaterials grows. In our Spotlight today we take a look at new biophysical research - a parallel study of carbon-nanoparticle uptake by plant and mammalian cells - that contributes to the general picture of the fundamental behaviors of nanoparticles in both biological and ecological systems.
In 2008, the Joint Research Centre, Institute for Health and Consumer Protection of the European Commission funded the project Engineered Nanoparticles: Review of Health and Environmental Safety (ENRHES). Last month, the ENRHES project released its final report. The overall aim of the ENRHES project was to perform a comprehensive and critical scientific review of the health and environmental safety of four classes of nanomaterials: fullerenes, carbon nanotubes, metals and metal oxides. The review considers sources, pathways of exposure, the health and environmental outcomes of concern, illustrating the state-of-the-art and identifying knowledge gaps in the field, in order to coalesce the evidence which has emerged to date and inform regulators of the potential risks of engineered nanoparticles in these specific classes.
The discussion about nanotechnology related safety issues so far has focused mainly on three areas - consumers getting exposed to products containing nanomaterials; nanomaterials getting released into the environment and potentially entering the food chain; and industrial workers being exposed to nanomaterials during the production process. There is an increasing number of reports and research papers dealing with these issues. Interestingly, while surveys of nanotechnology safety practices have concentrated on industrial settings, the safety issues of a significant number of people working with nanomaterials have not been addressed in a concerted matter - the researchers at university and private research laboratories who are doing all the early stage research and development. According to a survey conducted by a Spanish research group, it appears that the nanotechnology research community is not exactly at the forefront when it comes to following, not to mention setting, standards for safe practices for handling nanomaterials.
In a nanotechnology risk assessment study published last year, researchers concluded that the costs associated with nanomaterial risk assessment in the United States alone could range anywhere from $249 million to $1.18 billion and might take decades to complete at current levels of investment in nano-hazard testing. While research in quantitative risk characterization of nanomaterials is crucially important, and no one advocates abandoning this approach, scientists and policy makers must face the reality that many of these knowledge gaps cannot be expected to be closed for many years to come - and decision making will need to continue under conditions of uncertainty. At the same time, current chemical-based research efforts are mainly directed at establishing toxicological and ecotoxicological and exposure data for nanomaterials, with comparatively little research undertaken on the tools or approaches that may facilitate near-term decisions. A group of scientists suggests that this situation requires a significant research program in a fundamental area of timely, yet informed decision making regarding the potential risks of nanomaterials. They highlight some of these issues as well as outline some of the currently available tools and approaches for decision making regarding the potential risks of nanomaterials.
Experts and the public generally differ in their perceptions of technology risk. While this might be due to social and demographic factors, it is generally assumed by scientists who conduct risk research that experts' risk assessments are based more strongly on actual or perceived knowledge about a technology than lay people's risk assessments. Nevertheless, whether the risks are real or not, the public perception of an emerging technology will have a major influence on the acceptance of this technology and its commercial success. If the public perception turns negative, potentially beneficial technologies will be severely constrained as is the case for instance with gene technology. It is not surprising that a new study found that, in general, nanoscientists are more optimistic than the public about the potential benefits of nanotechnology. What is surprising though, is that, for some issues related to the environmental and long-term health impacts of nanotechnology, nanoscientists seem to be significantly more concerned than the public. Arguing that risk communication on nanotechnologies requires target-specific approaches, a group of researchers in Germany advocate the development of communication strategies that help people to comprehend nanotechnology, to differentiate between the fields of application and to gain an understanding of the cause and effect chains.
A scarcity of empirical data - especially regarding losses - hampers nanotechnology-related risk dialogue. Nanotechnology is a growing niche, so there is little litigation or loss history to analyze. Thus, much of the discussion of nanotechnology and its management flows from hypothetical examples. Less murky is the fact that nanotechnology is not a passing fad. It has innovative applications for a range of technologies and sectors, including drug delivery, medical imaging, integrated sensors, and semiconductors. The biggest areas of nanotechnology risk management concerns lies in workers' compensation and product liability. This article looks at industry responses and risk management strategies.
A newly published antibacterial activity mechanism study demonstrates how a single walled carbon nanotube (SWCNT) kills bacteria by the physical puncture of bacterial membranes. The nanotubes would constantly attack the bacteria in solution, degrading the bacterial cell integrity and causing the cell death. This work elucidates several factors controlling the antibacterial activity of pristine SWCNTs and provides an insight in their toxicity mechanism. With regard to carbon nanotubes, in early toxicological studies, researchers obtained confounding results - in some studies nanotubes were toxic; in others, they were not. The apparent contradictions were actually a result of the materials that the researchers were using.