Nano News: 02/27/15

European Food Safety Authority publishes risk assessment of nanotechnologies in food and feed

In accordance with European Food Safety Authority (EFSA)’s strategy for cooperation and networking with Member States, a Network for Risk Assessment of Nanotechnologies in Food and Feed was established in 2010. The overall goals of this Network are to facilitate harmonisation of assessment practices and methodologies; to enhance exchange of information and data between EFSA and MS; and to achieve synergies in risk assessment activities. The Annual reports of the Network inform the public and the EFSA Advisory Forum about its specific activities and achievements. During 2014, the Network followed-up on its priority areas and contributed to the making of inventory lists of applications of Nanomaterials already present in the food/feed chain ("Annual report of the EFSA Scientific Network of Risk Assessment of Nanotechnologies in Food and Feed for 2014"; pdf). During its meeting in 2014, the Network dedicated most of its discussions on relevant research results for possible toxic effects following the oral route of exposure. The Network exchanged views on the technical aspects and implications of the definition for Nanomaterial. The network also shared its views on the ongoing and upcoming risk assessments of EFSA on applications comprising implicitly or explicitly nanoforms. The Network updated its list with national research and contact details of national laboratories that can analyse nanomaterials in complex matrices. Summary Developing networking and stronger co-operation with the Member States and strengthening EFSA’s relationship with its institutional partners (EU and international) and stakeholders are among the key recommendations formulated by EFSA’s Management Board. In accordance with EFSA’s strategy for co-operation and networking with Member States, the Scientific Network for Risk Assessment of Nanotechnologies in Food and Feed (hereafter referred to as ‘Nano Network’) was launched. The Nano Network had its inaugural meeting in February 2011 and following this, one meeting per year is scheduled. The overall goals of the Nano Network are to provide a forum for dialogue among participants; build mutual understanding of risk assessment principles; enhance knowledge on and confidence in the scientific assessments carried out in EU; and to provide increased transparency in the current process among Member States and EFSA on nanotechnology. All this with the aim to raise the level of harmonisation of the risk assessments developed in the EU on nanotechnology. The Network is composed of representatives from 21 Member States and Norway.In addition, observers to this Network represent the Former Yugoslav Republic of Macedonia, Turkey and Montenegro. There is also representation from the European Commission (DGSANTE and JRC), from the EFSA Scientific Committee and the relevant Units/Panels. During 2014, the Network followed-up on its priority areas and contributed to the making of inventory lists of applications of Nanomaterials already present in the food/feed chain. At its 2014 meeting the Network focussed again on updates of research results from toxicological studies relevant for the oral route of exposure. Member States representatives presented relevant studies. The type of nanomaterials that are now occurring in the food/feed chain are mainly Titaniumdioxide (TiO2) and Synthetic Amorphous Silica (SAS). The evidence bases for oral toxicity and for conducting comprehensive risk assessments of these two materials is building up, but more research remains needed. Challenges to draw firm risk assessment conclusions reside in (1) the intake estimation (2) the possible worst-case absorption and the dose-dependence of absorption (3) the potential irrelevance of high dose oral toxicity studies for risk assessment (4) the extrapolation of kinetic data from rat to man (5) the nanoparticle determination in tissues, and (6) the many differences between the types of nanoforms of one nanomaterial (e.g. in kinetics and toxicity). Some differences in behaviour of different nanoforms have been observed, but there is no clear overview. A new issue of concern is that absorption is not linear with dose: high dose studies are often used for tox testing for estimation of safe dose, while the high dose may result in aggregation, agglomeration, gelation and as a consequence dose-dependent absorption. Challenges also remain to exist regarding the technical aspects for considering a material as a nanomaterial (NM) for the regulatory purpose of food labelling. The NanoDefine project (FP7) is expected to deliver by 2017 an implementable test-scheme for regulatory purposes to distinguish nano from non-nano. The Network agreed that regardless the current challenges and regardless the % of nanoforms in the bulk material (particle size% or mass%), EFSA should assess the nano-fraction, no matter how small. Food law, as being implemented by the EFSA Panels is covering nanomaterials. Nanomaterials are addressed mainly by cross-referring to the Guidance on the risk assessment of the application of nanoscience and nanotechnologies in the food and feed chain (EFSA Scientific Committee, 2011; pdf). The Network also updated its list with contact details of national laboratories that have equipment and know-how for analysing certain nanomaterials in complex matrices.

European Food Safety Authority publishes risk assessment of nanotechnologies in food and feed

Ordered nanostructures from benzene could pave the way for novel nanotechnology applications

A way to link benzene rings together in a highly ordered three-dimensional helical structure using a straightforward polymerization procedure has been discovered by researchers from RIKEN Center for Sustainable Resource Science and the University of Tokyo ("Aryne Polymerization Enabling Straightforward Synthesis of Elusive Poly(ortho-arylene)s"). “We expect our achievement to open up new areas of nanocarbon and materials science,” says Koichiro Mikami from the research team.

Figure 1: Aryne (Ar) is reacted using a copper catalyst (Cu(I)) to assemble an ordered helical structure. (Image: K. Mikami, RIKEN Center for Sustainable Resource Science) Benzene (C6H6) is the simplest of the wide range of ‘aromatic’ compounds, which have rings of carbon atoms surrounded by ‘delocalized’ electrons that circulate around the molecules. A long-standing challenge for chemists has been the development of a straightforward way to link rings of benzene together in a regular manner such that the carbon atoms are bonded directly to their neighbors in adjacent rings to form a structured material. Masanobu Uchiyama from RIKEN and the University of Tokyo and his colleagues Mikami and Yoshihide Mizukoshi developed their linking procedure starting with the molecule aryne, which is very similar to benzene but has a triple bond between two adjacent carbon atoms in the ring (Fig. 1). After investigating many different combinations of chemicals and solvents, the researchers found a procedure involving copper ions that reliably links the rings together at the ortho position by a self-propagating polymerization reaction. The product, called poly(ortho-phenylene), is the simplest member of wide range of possible poly(ortho-arylene)s that could carry a selection of different atoms or chemical groups in place of one or more of the hydrogen atoms on the benzene-derived rings. The researchers found that their poly(ortho-phenylene) molecules have a regular and highly ordered three-dimensional structure consisting of stacked six-carbon rings. Such highly ordered materials are precisely the kinds of chemical building blocks that might be put to good use as components for nanotechnology. Having made this crucial breakthrough, the researchers’ next steps will be to explore the size and variety of structures that can be assembled by their technique. The team has so far managed to link approximately 100 rings together, but plans to extend this further and to control chain lengths and physical characteristics. “We are exploring the electrical, photodynamic and thermal properties of these poly(ortho-phenylene)s toward creating novel electronic devices and liquid crystals,” explains Mikami. In addition to providing scaffolding structures, nanocompounds become most interesting when they can respond to light, electric fields or the presence of other chemicals in precise and useful ways. Mikami says the team is also looking at forming chemical cross-links between individual helical chains, extending the fabrication possibilities to another dimension.

New research signals big future for quantum radar

A prototype quantum radar that has the potential to detect objects which are invisible to conventional systems has been developed by an international research team led by a quantum information scientist at the University of York. The new breed of radar is a hybrid system that uses quantum correlation between microwave and optical beams to detect objects of low reflectivity such as cancer cells or aircraft with a stealth capability. Because the quantum radar operates at much lower energies than conventional systems, it has the long-term potential for a range of applications in biomedicine including non-invasive NMR scans.

The research team led by Dr Stefano Pirandola, of the University's Department of Computer Science and the York Centre for Quantum Technologies, found that a special converter - a double-cavity device that couples the microwave beam to an optical beam using a nano-mechanical oscillator - was the key to the new system. The device can either generate microwave-optical entanglement (during the signal emission) or convert a microwave into an optical beam (during the collection of the reflection beams from the object). The research is published in ("Microwave Quantum Illumination"). A conventional radar antenna emits a microwave to scan a region of space. Any target object would reflect the signal to the source but objects of low reflectivity immersed in regions with high background noise are difficult to spot using classical radar systems. In contrast, quantum radars operate more effectively and exploit quantum entanglement to enhance their sensitivity to detect small signal reflections from very noisy regions. Dr Pirandola said that while quantum radars were some way off, they would have superior performance especially at the low-photon regime. "Such a non-invasive property is particularly important for short-range biomedical applications. In the long-term, the scheme could be operated at short distances to detect the presence of defects in biological samples or human tissues in a completely non-invasive fashion, thanks to the use of a low number of quantum-correlated photons. "Our method could be used to develop non-invasive NMR spectroscopy of fragile proteins and nucleic acids. In medicine, these techniques could potentially be applied to magnetic resonance imaging, with the aim of reducing the radiation dose absorbed by patients."