engleski

The relevance of the physico-chemical transformations of metallic nanoparticles for nanosafety - analytical aspects

Recent medical and commercial uses of metals employ them progressively in the form of nanoparticles (NPs) due to the unique physicochemical properties and increased reactivity of a substance at the nano-sized level. Such fast development of nanotechnology in numerous industrial and biomedical applications has raised concerns about the impact of NPs on the human health and environment. Unique physicochemical properties of NPs such as high adsorption capacity, hydrophobicity, surface charge, optical and magnetic properties, or catalytic activity lead to different alterations of NPs when dispersed in certain media. In comparison to the bulk material, the colloidal stability of the metallic NP is usually more complicated. In colloidal systems, there are several possible interactions between the surface atoms of NPs and the molecules presenting in the media, like dissolution, adsorption, binding, and aggregation, all influencing biological or environmental impacts and fate of NPs. In order to manipulate and analyse the NPs interactions in certain media appropriately, a study of the state of the NPs at each step of the exposure is mandatory including exhaustive characterisation by a series of combination of solid state and analytical chemistry techniques like UV-Vis and fluorescence spectroscopy, dynamic and electrophoretic light scattering, electron microscopy, mass spectrometry hyphenated to different separation techniques. A general methodology for such direct, systematic and quantitative observations, however, is still lacking, in part because the most common approaches tend to primarily focus on biological or physical aspects of inclusion media. Another problem comes from the exceptional physicochemical properties of metallic NPs, such as large surface area and chemically active surface, which provoke their interferences with assay components and/or detection systems used by in vitro methods and analytical techniques during safety evaluation of NPs. Artefacts introduced in this way can obscure evidence and results for NPs fate in samples of interest. In view of existing gaps for a robust safety testing of novel NPs, it is imperative that any investigation of biocompatibility and safety of NPs be carefully accomplished bearing in mind every possible interference and interaction with the test system. To understand the behaviour and impacts of NPs, further development of the analytical techniques is expected to make the approach increasingly flexible.

metallic nanoparticles; biotransformation; risk assessment

nije evidentirano