2. Increase in consumer products with nanoclaim Number of total products listed, by date of inventory update, with regression analysis. August 2009 Nanotechnology Consumer Products Inventory, Woodrow Wilson International Center for Scholars, Washington, USA
3. Most commonly used nanomaterials in consumer products Nanotechnology Consumer Products Inventory, August 2009, Woodrow Wilson International Center for Scholars, Washington, USA
5. Why are we concerned? Nanomaterials (nanoparticles) can have sizes similar to structures at subcellular level. Reminder, chemicals (molecules) also do this. nanopore, dendrimer, nanoshell, fullerene, nanotube, nanowire, nanocrystalls cantilevers, microneedles Nanotechnology lab-on-a-chip erythrocyte apple water molecule virus DNA Nature Nanometres 10 -1 1 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8
6. Increase in reactivity due to increase in surface All: 1 x 1 cm Decrease in size results in (enormous) increase in surface area 6,000cm 2 1 x 10 12 1 µm 60.000.000 cm 2 (600km 2 ) 1 x 10 21 1 nm 60 cm 2 1,000 1 mm 6 cm 2 1 1 cm Total Surface area number size
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8. Problems with dispersion in toxicity testing Gold nanoparticles in PBS, A and B 10 nm, C 50 nm, and D 100 nm diamater) De Jong et al., Biomaterials 29, 1912, 2008
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10. Is nano more toxic than micro material? Depends on the dose metric used for particle toxicity Oberd ö rster et al., Environ Health Perspect 113, 823, 2005 This was demonstrated for local effects in the lung after inhalation exposure. What about other routes of exposure (oral, dermal, intravenous)?
15. Nanofibres, issue on CNT versus asbestos Scientific publications on possible cancer risk Sakamoto Y, Nakae D, Fukumori N, Tayama K, Maekawa A, Imai K, Hirose A, Nishimura T, Ohashi N, Ogata A. Induction of mesothelioma by a single intrascrotal administration of multi-wall carbon nanotube in intact male Fisher 344 rats. The Journal of Toxicological Sciences, 34, 65-76, 2009 nature nanotechnology | VOL 3 | JULY 2008 | 423
16. Poland et al 2008 MWCNT induce chronic inflammation Takagi et al 2008, Sakamoto et 2009 MWCNT induce tumors in P53 mice and F344 rats Muller et al 2009 MWCNT do NOT induce tumors in 2 year study Nygaard et al 2009 CNT act as adjuvant
20. Nanostructures in pleural fluid and in pulmonary epithelial cell Song et al, Eur Resp J 34, 559-567, 2009 Bar represents 200 nm
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Editor's Notes
How can you define a nanoparticles dose To give you an impression how size, particle number and surface area are related to each other, i can show you 3 times a cube of one by one centimetre. The first is only 1 particle with in total 6 square cm. If the cube is build up from little 1 mm cubes, then 1000 cubes are needed with a total surface area of 60 square cm. If the particles are 1 nm cubes, then …. A lot particles would be needed to fill the cube with a total surface area of 600 square kilometres. Inside the body, the surface of particles is in contact with the tissue
