Workshop Summary: Research Progress on Environmental, Health, and Safety Aspects of Nanotechnology - Research Progress on Environmental Health and Safety Aspects of Engineered Nanomaterials - page 90

efforts to communicate results from NIOSH public-private partnerships, including publication of research
results from NIOSH and development of memoranda of understanding at key research and development
centers; he stated that further development of public-private interactions is needed.
Dr. McNeil reported that NCI-Frederick (now called the Frederick National Laboratory for
Cancer Research or the Frederick National Lab [Reynolds 2012]) recently became a national laboratory
and is able to conduct research through public-private partnerships and with other agencies. It offers a
niche where material scientists, toxicologists, and others can, for example, examine specific questions
regarding interactions between nanomaterials and biologic systems. Dr. McNeil provided several
examples of the laboratory's work with NIEHS and FDA on nanomaterials and an industry partnership to
assess toxicity of nanocrystalline cellulose.
Perspectives of Researchers
Several researchers discussed directions and initiatives that they considered to have the highest
priority for addressing uncertainties about EHS aspects of ENMs. Martin Philbert, of the University of
Michigan School of Public Health, discussed the need to learn lessons from nanomedicine, emphasizing
that drug development takes longer than it used to and that public-private partnerships are needed. He
suggested the need to consider the “rule of six” for nanotechnology EHS research that was originally
developed to move clinical drug development forward by identifying a simple set of physicochemical
parameter ranges that the compounds needed to meet for design and selection (see Keller et al. 2006). He
emphasized that there are few chronic safety studies on ENMs and that we need to move beyond classical
toxicology to less expensive, higher-throughput analyses.
Robert Tanguay, of Oregon State University, noted that ENM behavior depends completely on a
material's inherent properties and that the goal of EHS research is to develop methods for predicting
behaviors from the inherent properties. He described progress toward filling research gaps: distribution of
some reference materials and their use in cross-evaluation of models, wider acceptance of minimum
characterization standards (although perhaps not yet sufficient), greater understanding of the dynamic
behavior of ENMs, greater understanding of the need for precision engineering to support structure-
response relationship studies, and application of Tox21 1 principles to in vitro and in vivo studies (for
example, in zebrafish). However, the focus remains on simple materials with a heavy emphasis on silver
ENMs and metal oxides. Apart from that progress, Dr. Tanguay commented that the key toxicologic
question remains: What are the unique properties that influence toxicity? Dr. Tanguay described research
that is needed to explore the unique properties of ENMs systematically and to understand how these
properties influence molecular interactions and biocompatibility. The needs include further development
of characterization methods for understanding the principles that drive the dynamic behavior of materials,
identification of a minimum set of testing platforms for comparative ENM bioactivity assessments,
development and distribution of standard materials for calibrating assays, identification of more diverse
sets of materials for comparative testing, more aggressive data-sharing strategies, and implementation of
an informatics platform for data-mining.
Mark Wiesner, of Duke University and a member of the committee, discussed work of the Center
for the Environmental Implications of Nanotechnology (funded by EPA and NSF) and the need to
elucidate principles that determine environmental behavior of nanomaterials and to translate data on
the environmental behavior of ENMs into risk. Dr. Wiesner asked, What nanomaterial properties and
environmental conditions control the spatial and temporal distributions of nanomaterials in the
environment? He emphasized the need to look at next-generation nanotechnologies, in that much of the
EHS community is still focused on first-generation materials.
1 Tox21 is a collaboration among EPA, NIEHS, the National Human Genome Research Institute, the National
Institutes of Health Chemical Genomics Center, and the Food and Drug Administration that was established to
leverage resources to advance the recommendations in the 2007 National Research Council report Toxicity Testing
in the 21st Century: A Vision and a Strategy .