Timing, hosts and locations of (grouped) events of NanoImpactNet

NanoSafetyCluster - Compendium 2012
Since the interaction processes depend on the encountered atoms,
on the structure of the sample and on the sort and energy of the
ions, the detection of secondary products of the interactions
allows the determination of the elemental content and distribution
in a sample. IBM has been used successfully to study the
permeation of titanium dioxide NPs after topical application
(Menzel et al., 2004). Since the technique is time consuming, EM
and CLSM serve as supporting techniques. CLSM requires
sophisticated labelling of the NPs ensuring strong fluorescence,
but trying to avoid the use of conjugated labels, which would
interfere with the cellular uptake and response.
TEM images of H460 cells incubated with TiO2 NPs taken after 4, 12,
24, and 48 h incubation
4) Understanding the interaction of NPs with cellular and
extra-cellular components.
For assessment of the fate and interaction of NPs in the organism,
investigations of NP-protein interaction and stability of NPs in
different biological compartments will be carried out by
biochemical methods focusing on measuring complementary
agents and by means of binding studies with Fluorescence
Correlation Spectroscopy (FCS). In FCS fluctuations in the
fluorescence intensity from a confocal volume in a sample, which
are caused by diffusional and rotational processes are measured
and correlated temporally (Haustein et al., 2003). These results can
be related to aggregation, association, polymer dynamics and,
most importantly, in the proposed research, binding reactions. The
technique has been successfully applied to measure binding
constants and association of biomolecules. It has the advantage of
only requiring very few fluorescent molecules in the confocal
volume, and this can be applied in combination with CLSM to
measure binding and association within cell compartments. The
stability and corrosion of NPs is being investigated by
biodissolution tests in an environmentally controlled, stirred batch
reactor.
5) Determination of physiological effects of NPs in vitro.
It is a well-accepted hypothesis that reactive oxygen species may
play an important role in particle-induced toxicity (Limbach et al.,
2007; Xia et al. 2006; Sayes et al., 2006). Great differences in
toxicity have been found between different oxide NPs, and in vitro
studies suggest that the levels of toxicity may correlate to the
reactive oxygen species (ROS) formation capacity of the NPs
(Limbach et al., 2007; Jeng & Swanson, 2006, W. Lin et al. 2008),
and also the release of ions. Comparatively more work has been
completed on quantum dots, fullerenes and carbon nanotubes
(CNTs) (Cui et al, 2004; Monteiro-Riviere et al, 2005; Lam et al,
2004; Maynard et al, 2004; Derfus et al, 2004; Kirchner et al, 2005;
Hoshino et al, 2004; Schrand et al., 2007). Immune competent cells
are specialized in the recognition of external factors in the skin,
mucosa, blood, digestive and lung tissue, etc. They are also
responsible for the subsequent production of signal molecules
(cytokines), which activate other mechanisms of the immune
defence system such as antibody production, macrophage
activation, lymphocyte activation and proliferation. In addition,
humoral factors such as complement, or acute phase proteins,
participate actively in the inflammatory process and in the
destruction of foreign elements. The subsequent changes in cell
physiology induced by the presence of the NPs will have a
tremendous impact on the induction and course of the immune
reactions as a whole. For example, NPs can modify endogenous
protein, inducing allergy processes, or induce macrophage
activation in lungs, leading to a chronic inflammation with fibrosis
(Lam et al., Crit Rev Toxicol. 2006). ATII cells are by far the most
frequent cell in the alveolar lining. They are, among other
functions, responsible for secretion and recycling of lung
surfactant and a number of defence proteins.
Effect of the different NPs in cell viability. Graphs showing the effect
on cell viability of the different Nps, by Quick cell colorimetric assay,
at 48 h, in different cell types: A549 (2a), SK MES1 (2b) NCI H460 (2c),
and HeLa (2d). Nanoparticles were considered non-toxic if at 48h cell
viability reached at least 75%. All the assays were performed twice for
each cell line, and in triplicate for each nanoparticle concentration
6) Risk of exposure and toxicological effects of metal and
metal oxide NPs.
The knowledge generated by the different workpackages of
HINAMOX will be used to make an assessment of the risks
associated with these kinds of NPs following European standards
suggested by the Scientific Committee on Emerging and Newly
Identified Health Risks (SCENIHR, 2007). The data gathered in this
project utilizing in vitro and in vivo models will be used to support
38 Compendium of Projects in the European NanoSafety Cluster