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Nanotechnology is a rapidly growing field with silver nanoparticles (AgNP) in particular utilized in a wide variety of consumer products. This has presented a number of concerns relating to exposure and the associated toxicity to humans and the environment. As inhalation is the most common exposure route, this study investigates the potential toxicity of AgNP to A549 alveolar epithelial carcinoma cells and the influence of a major component of lung surfactant dipalmitoylphosphatidylcholine (DPPC) on toxicity. It was illustrated that exposure to AgNP generated low levels of oxidative stress and a reduction in cell viability. While DPPC produced no significant effect on viability studies its presence resulted in increased reactive oxygen species formation. DPPC also significantly modified the inflammatory response generated by AgNP exposure. These findings suggest a possible interaction between AgNP and DPPC causing particles to become more reactive, thus increasing oxidative insult and inflammatory response within A549 cells

Establishing realistic exposure scenarios is critical for cytotoxic investigation of silver nanoparticles (AgNP) in the gastrointestinal tract. This study investigated the potential interaction with and effect of biofluid components, namely cholic acid, deoxycholic acid and ursodeoxycholic acid, on AgNP toxicity. Two cell lines corresponding to organs related to the biofluid components were employed. These were HepG-2 a hepatocellular carcinoma derived from liver tissue and Hep2 an epithelial cell line. Physiochemical and cytotoxic screening was performed and the ability of biofluid components to modify AgNP cytotoxicity was explored. No alteration to the physiochemical characteristics of AgNP by biofluid components was demonstrated. However, biofluid component addition resulted in alteration of AgNP toxicity. Greater reactive oxygen species induction was noted in the presence of cholic acid and deoxycholic acid. Ursodeoxycholic acid demonstrated no modification of toxicity in HepG-2 cells; however, significant modification was noted in Hep2 cells. It is concluded that biofluid components can modify AgNP toxicity but this is dependent on the biofluid component itself and the location where it acts.

Nanotechnology is regarded as one of the key technologies of the future and associated with high expectations by politics, science and economy. Artificially produced nanosized particles and nanoscale system components have new properties which are of importance for the development of new products and applications. Such new properties of materials and substances result from the special properties of surfaces and interfaces and in part, from the geometric shape of the material. In theory nanoparticles (NPs) can be produced from nearly any chemical; however, most NPs that are currently in use today have been made from transition metals, silicon, carbon (single-walled carbon nanotubes; fullerenes), and metal oxides (zinc dioxide and titanium dioxide). Potentially harmful effects of nanotechnology might arise as a result of the nature of the NPs themselves, the characteristics of the products made from them, or aspects of the manufacturing process involved (Borm and Kreyling, 2004). The large surface area, crystalline structure, and reactivity of some NPs may facilitate transport in the environment or lead to harm because of their interactions with cellular material. In the case of nanomaterials, size matters, and could facilitate and exacerbate any harmful effects caused by the composition of the material. The highest risks for humans and the environment are associated with nanomaterials contained in products in the form of free particles. As long as NPs remain firmly embedded in materials, hardly any risk should be expected (Brouwer, 2004). However, it has to be clarified in these cases whether and in which form nanomaterials can be released into the environment during the production process, the use of a product, due to ageing and degradation as well as during disposal and recycling processes. Of course, also in the case of nanomaterials, environmental risk assessment should take into account their entire life cycle.

The application of nanotechnology in the food and feed industry offers many potential benefits for both consumers and manufacturers.The ultrafine dimensions of nanoparticles, and consequently their very large surface area, enable them to function more effectively than conventional macro-scale structures in many applications. Nanotechnology is however a relatively new area of science and the benefits and risks associated with its use in the food and feed industry are not fully understood at this time.This brings with it new challenges in ensuring the safety of food and feed that has been produced with the aid of nanotechnology. This report provides an overview of current and potential applications of nanotechnology in the food industry, which may equally be applied in the feed industry. The possible risks of nanotechnology, together with the adequacy of the existing EU regulatory framework in the control of any potential risks, are also examined with a view to determining what further legislative measures, if any, may be necessary to safeguard food safety

Inclusion complexes of saccharides and HiPco Carbon Nanotubes (HCNT) were formed, resulting in water soluble complexes. These complexes were then characterised using a variety of spectroscopic techniques. Raman spectroscopy was used to probe changes in the vibrational character of both the host and guest species and also to assess if any selectivity of tube diameter occurred. UV-Vis-NIR and circular dichroic spectroscopies were used to assess the effect of inclusion on the electronic properties of the tubes. Spectroscopic analysis of these species showed clear evidence of an intermolecular interaction between the host material and the HCNT.

Hybrid systems of the conjugated organic polymer poly (p-phenylene vinylene-co-2,5- dioctyloxy -m-phenylene vinylene) (PmPV) and HiPco SWNT are explored using spectroscopic and thermal techniques to determine specific interactions. Vibrational spectroscopy indicates a weak interaction and this is further elucidated using Differential-Scanning Calorimetry and Temperature Dependent Raman pectroscopy. Two distinct transitions in region of -60C and + 60C are investigated.

This study attempts to develop an understanding of the electronic processes active within the solid state of C60. The emphasis throughout the work has been upon the generation and spectroscopic identification of any species, which could potentially contribute to electronic conduction in thin films of C60. The relative importance of these inter-and intramolecular processes in terms of their contribution to the electronic transport is discussed through the comparison of the properties of the molecule with the properties of the bulk solid Initially the low intensity optical properties of the C60 molecule in solution and in solid were assessed. Vibrational spectroscopy of C60 in the solid state indicated that C60 was predominantly molecular in character, however electronic spectroscopy revealed features, which were specific to the solid. These features have been attributed to an intermolecular charge transfer state, which can potentially contribute to the generation of photocarriers. Further optical analysis at higher intensities revealed that the excited state properties of molecular C60 were dominated by an extremely fast intersystem crossing rate (~1.2ns) to the first triplet state manifold. This was indicated by the rapid evolution of a triplet - triplet absorption at ~750nm in the transient absorption measurements. This molecular triplet was assigned the Raman signature 166cm-1 and was seen to play an integral part in the 2+2 - ycloaddition mechanism proposed for the photopolymerisation of C60 from solution. The molecular triplet was identified for the first time in the solid state using Raman spectroscopy and was seen to be positioned at 1466cm-1 as in solution. In addition to the molecular triplet a second excited state species positioned at 14663cm-1 was observed in the solid state. It was proposed that the species positioned at 1463cm-1 was an excited co-operative involving two or more molecules in the solid. A temperature dependence study of the excited state.