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

protocols with real biological samples from WP and
perform a final intra-vial and vial-vial homogeneity study
will be done on the TiO2 samples. Finally, we prepare
publications on the ENPRA dispersion protocol and coauthoring
papers lead by researchers outside the WP
WP4 – Dose-response assessment I: Development of in vitro
models for assessing the potential hazards of ENP
The progress of WP4 in the first reporting period is according to
the ENPRA workplan. Specifically, we have achieved the
following:
1. For the kick off meeting all tasks were detailed via a
spreadsheet, dividing each task into target organ/cell
types and the relevant endpoints for each target.
2. Using the spreadsheet, each partner identified which
target and endpoints they were to be responsible for
in order to identify areas for collaboration and
potential gaps. This was discussed via teleconference
in order to allow coordination of collaboration. No
gap was identified.
3. Key users of protocols that spanned multiple targets
were identified and these groups generated standard
operating procedures for these protocols. These
protocols have been shared amongst partners via the
ENPRA website. In addition they have been provided
to NanoImpactNet for conversion into NIN protocol
format.
4. A panel of 10 ENP were distributed to all partners via
Mercator.
5. Using the agreed protocols, each group tested all of
the particles for cytotoxicity in the relevant target cell
types in order to determine LC50 values.
6. LC50 values have been assembled into a summary
spreadsheet to enable future strategic decision
making for WP4 and WP5. This spreadsheet has
allowed identification of relatively high toxicity
materials (ZnO and Ag) and relatively low toxicity
materials (MWCNT and TiO 2), but it has also allowed
identification of cell type - particle type interactions
which are relatively sensitive (e.g. macrophages and
long MWCNT). This information, combined with the
information from the characterisation WP, will allow
prioritisation of particles for mechanistic studies and in
vivo studies.
The most notable results so far for WP4 are:
1. The clear consistency between all partners that the
ZnO and Ag particles are relatively toxic;
2. all other ENP are generally of no significant toxicity at
the doses tested.
For the second reporting period, we continue with the
following:
1. Each group has tested all of the particles in the
relevant target cell types in order to determine LC50
values.
2. LC50 values have been assembled into a summary
spreadsheet to enable future strategy decision making
for WP4 and WP5.
NanoSafetyCluster - Compendium 2012
3. All Cytotoxicity data has been submitted for data
analysis and database generation in other WPs.
4. Much of the cytokine data has been submitted for data
analysis and database generation in other WPs.
5. Mechanistic studies now focus on a minimum of the 2
MWCNT, the Ag, uncoated ZnO and one TiO2.
6. One publication is already in press for the
genotoxicology studies and a number of other
manuscripts are in advanced stages of preparation.
WP5 – Dose-response assessment II: Using in vivo models for a
kinetics study and verification of in vitro results
The progress of WP5 in the first reporting period is according to
the ENPRA workplan. Specifically, we have achieved the
following:
1. The major part of the study has been conducted
2. The dose-response relationships of the full panel of
ENP after acute exposure have been executed. The
study has been performed using the finalised
dispersion protocol to make the particle suspensions
and the finalised instillation protocol. The data are
being collected and currently analyzed.
The most notable results so far for WP5 are:
1. Results of kinetic study using TiO 2 have been reported.
ENP taken up into the lungs cross the lung membrane
and reach the blood stream. This leads to an
accumulation in organs in a size dependent manner:
the smaller the ENP, the higher the accumulation in
the organs.
2. The intratracheal instillation has been performed for
the acute dose-response study. Preliminary results
show a very low acute inflammatory potential, except
for ZnO.
3. In contrast to the in vitro results, nano-silver does not
evoke an acute inflammatory response.
4. The MWCNT seem to be less acutely toxic compared to
other MWCNT studies described in literature, but a
detailed comparison in particle characteristics needs to
be done to give an idea why that is.
5. Data from the in vitro studies and the preliminary
results from the acute in vivo study have lead to a
critical re-evaluation of the study set-up for the in vivo
studies in mice with a pre-existing risk factor.
For the second reporting period we have continue with the
following
1. Bio-kinetics inhalation studies with Gold and Silver ENP
have been performed and the data analysed. The gold
ENP undergo the same metabolic and biokinetics
when comparing inhalation versus instillation. Rather
unexpectedly the entire NP translocation across the
air-blood-barrier did not differ significantly and the
retained fractions in prominent secondary organs like
liver and spleen were also not significantly different.
This result is insofar important as it suggests that the
rather inexpensive method of instillation provides a
rather simple application for NP delivery to the lungs
Compendium of Projects in the European NanoSafety Cluster 19