Non-invasive study of natural dyes on historical textiles from the collection of Michelangelo Guggenheim.

A selection of historical textile fragments from the Venetian art dealer Moisè Michelangelo Guggenheim collection, ranging from XV to XVIII century, has been investigated by means of non-invasive techniques in order to reveal the coloring materials. Imaging was preliminarily used to visually investigate the selected artwork fragments in order to investigate their structure and conservation conditions; Fiber Optics Reflectance Spectroscopy (FORS) allowed recognizing the main natural dyestuffs, such as indigotin and anthraquinones-based compounds, except the yellow ones, difficultly identifiable when using this non-invasive technique. Collected spectroscopic data have been also elaborated by using a clustering algorithm that permitted to group collected spectra on the basis of similar properties and evidencing their inflection point wavelength as the most influencing feature.

Towards an alternative testing strategy for nanomaterials used in nanomedicine: lessons from NanoTEST.

In spite of recent advances in describing the health outcomes of exposure to nanoparticles (NPs), it still remains unclear how exactly NPs interact with their cellular targets. Size, surface, mass, geometry, and composition may all play a beneficial role as well as causing toxicity. Concerns of scientists, politicians and the public about potential health hazards associated with NPs need to be answered. With the variety of exposure routes available, there is potential for NPs to reach every organ in the body but we know little about the impact this might have. The main objective of the FP7 NanoTEST project ( www.nanotest-fp7.eu ) was a better understanding of mechanisms of interactions of NPs employed in nanomedicine with cells, tissues and organs and to address critical issues relating to toxicity testing especially with respect to alternatives to tests on animals. Here we describe an approach towards alternative testing strategies for hazard and risk assessment of nanomaterials, highlighting the adaptation of standard methods demanded by the special physicochemical features of nanomaterials and bioavailability studies. The work has assessed a broad range of toxicity tests, cell models and NP types and concentrations taking into account the inherent impact of NP properties and the effects of changes in experimental conditions using well-characterized NPs. The results of the studies have been used to generate recommendations for a suitable and robust testing strategy which can be applied to new medical NPs as they are developed.

Biomarkers in Mytilus galloprovincialis exposed to suspensions of selected nanoparticles (Nano carbon black, C60 fullerene, Nano-TiO2, Nano-SiO2).

The potential for ecological toxicity associated with nanomaterials is a growing area of investigation, in particular in the aquatic environment. In suspension feeding invertebrates, the cellular immune system and digestive gland are likely to be targeted, due to their highly developed processes for the cellular internalisation of nano- and micro-scale particles that are integral to key physiological functions such as cellular immunity and intracellular digestion. We have recently demonstrated that suspensions of selected commercial nanomaterials, namely Nano carbon black (NCB), C60 fullerene (C60), Nano-titanium dioxide (n-TiO2) and Nanosilica (n-SiO2) induce oxyradical production and lysosomal enzyme release in the hemocytes of the marine mussel Mytilus in vitro. In this work the possible effects of in vivo exposure to these NPs were investigated. Mussels were exposed to different concentrations (0.05-0.2-1-5mg/l) of NP suspensions for 24h and different biomarkers were evaluated in hemocytes, digestive gland and gills. Characterisation of NP suspensions in artificial sea water (ASW) was performed, indicating the formation of agglomerates of different sizes in the nano-micromolar range for different types of NPs. Formation of larger agglomerates was observed at the end of exposure. The results show that all NP suspensions induced significant lysosomal membrane destabilisation in both the hemocytes and the digestive gland, with NCB>>C60>n-TiO2, >n-SiO2. In the digestive gland, all NPs induced lysosomal lipofuscin accumulation only at the highest concentrations tested to a different extent depending on the NP type. NCB, TiO2 and SiO2 also induced lysosomal neutral lipid accumulation. Moreover, all NPs increased the activity of the antioxidant enzyme catalase, with n-SiO2>NCB≅TiO2>C60; NCB and n-TiO2 also stimulated glutathione transferase (GST). Changes in catalase and GST activities were also observed in gills, with both increases and decreases depending on NP type and concentration. The reported results demonstrate that in mussels responses to exposure to NP suspensions involve changes in lysosomal and oxidative stress biomarkers in the digestive gland, suggesting uptake of NP aggregates/agglomerates mainly through the digestive system. Overall, these data further support the hypothesis that suspension feeding invertebrates represent a significant target for NPs in the aquatic environment.