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

NanoSafetyCluster - Compendium 2012
4 Project Description and Organisation
There are several striking features of the program that require
particular emphasis and attention in the S/T methodology. These
issues, and their impact on methodology are:
(i) Relative immaturity of the experimental field, lack of
clearly validated data, and lack of uniformity on the
understanding of the role and methods by which
quantitative and reproducible data are acquired.
(ii) The long time required to generate extensive collections
of such data, and the requirement to be more pro-active
and constructive in the interim.
(iii) The need for realistic, achievable outcomes that can be
checked at every point.
Figure 3. Electron Microscopy images after 10 minutes, 1 hour and
24 hours of exposure to 25 µg/mL 50nm red-fluorescently labelled
SiO 2 nanoparticles. From these images the localisation of the
nanoparticles on the surface (some in clathrin and caveolin
receptors), early endosomes and finally lysosomes can be
observed. Co-localisation of the red-fluorescent SiO 2 nanoparticles
with green Lyso-tracker dye is shown in the confocal microscopy
image in the top right, confirming the final end point as the
lysosomes. Data such as these are now developed to a
quantitative level, including quantitative sub cellular localizations.
EM and confocal data from Partner 1, sketch of cell re-drawn from
Watson et al. 7
Intimate Collaboration between experiment-modeller-theorist
The current lack of large amounts of data that can be
considered reproducible suggests that modellers must rely
heavily on the science and understanding, which is now growing
rapidly. This understanding of relevant parameters and
mechanisms can be gained using a few examples, well studied,
and can be widely applied in models. Thus, our approach is
based on an implementation of the mechanistic understanding
in an interactive manner. Thus, the model when created is
tested using new sets of experimental data, and checkpoints
applied to ensure success in a modular approach. Success in this
kind of approach (albeit in a limited manner in the early days) is
immediate. For example, the simplest uptake model has already
been checked experimentally, and the most interesting
outcome noted that one had to include the effects of cell
division to obtain quantitative agreement. Expansion of this
concept allows for a proactive impact on the broader
experimental community, from the earliest days, and does not
require very large amounts of data before this can occur.
Robust organization to filter data inputs to ensure quality
At all points of the program, the acquisition of high quality data
is key, and this is reflected in the accompanying chart, as well as
the WP descriptions and the management processes. It is
helpful that Partner 1 has an extensive experimental as well as
modelling program, as this allows the Unit leaders to be in daily
contact, interrogating the experimental information, and
models. It ensures such details that the correct parameters and
characteristics of the particles are recorded for the models. This
allows us to template the process into a more formal
management group activity where the young leaders from
experiment and theory-modelling are required to evaluate data
also emerging from other collaborators outside of the present
program. This intimate day-to-day link between modeller and
experimentalist we consider as foundation for the success of
the project.
Progressive and systematic checks at modular level
Whilst we consider the program highly ambitious, we do feel
that it will succeed, and that it is an essential building block on
the constellation of such projects. The careful preliminary
research and preliminary results in each segment enabled by a
series of exchanges and visits in the last year as the program
was built certainly gave us much assurance. However, the
design and modularity of the project, with the capacity of
exposure to the critical evaluation of experimentalists at each
step and at each level is a key element. Thus, experience of the
modellers and theorists in the program suggests that the
developments of highly complex models that can only be tested
at late stages are risky, and prone to failure. Here, for example,
the capacity of a model module to predict the effective
interaction between a nanoparticle (complete with corona) and
cell membrane can be explicitly tested in a simple experiment.
Similarly, the phenomenological model’s capacity to model the
steady state concentration (for example, in basolateral
endosomes in the BBB model) and link that correctly to the
macroscopic flux across the BBB barrier can be explicitly
checked with live cell imaging, where we have already
established the reproducibility of such measurements. Thus,
each modular component can be exposed to scientific checks,
as well as the usual software validity checks.
The final Integration and Co-ordination tasks (within WP5)
ensure that the modules remain in overall conceptual and
operational alignment with each other within the program, to
allow for a later integration with the future objective of
modelling nanoparticle in vivo biodistribution. Crucially, this
work package also allows for the co-ordination of
200 Compendium of Projects in the European NanoSafety Cluster