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Engineered Nanomaterials and Human Health Sally S. Tinkle, PhD National Institute of Environmental Health Sciences National Institutes of Health Department of Health and Human Services 27 January 2007. Nanomaterials: Biocompatibile or Toxic?. Desirable Applications of Nanotechnology.
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Engineered NanomaterialsandHuman HealthSally S. Tinkle, PhDNational Institute of Environmental Health SciencesNational Institutes of HealthDepartment of Health and Human Services27 January 2007
Nanomaterials: Biocompatibile or Toxic?
Desirable Applications of Nanotechnology “Smart” therapeutics Targeted molecular imaging agents Biological sensors/ diagnostic tools Tissue engineering Nano-enabled consumer products
Novel Properties of Nanomaterials • Size • improved electrical, magnetic, optical properties • Surface area • increased reactivity, selectivity, sensitivity • Shape • influences physico-chemical properties • Surface chemistry and modifications • composition and application specific
Scaling from Millimeters to Nanometers Naturally Occurring Manufactured Manufactured Head of a Pin 1 – 2 mm Red Blood Cell 2 – 5 mm Microelectrical Devices 10 – 100 mm ATP synthase 10 nm Fullerenes ~1 nm Nanowires ~20 – 50 nm DNA ~2 nm diameter Nanotubes ~20 nm width Nanospheres ~30 – 96 nm
Size and Surface Area Single Particles Agglomerated Particles Carbon Wires Titanium Dioxide Fullerenes Warheit et al., Tox Sci 2006
Effect of Size : Translocation Systemic Dermal 50 um Ryman-Rasmussan, Tox Sci, 2006 Nemmar et al., Circ, 2002
Effect of Surface Area on Biology Oberdorster et al, Env Health Persp, 2005
Examples of Surface Modifications Chemically Modified Fullerene Fullerene Mix-modified dendrimer Phospholipid-coated SWCNT
C60(OH)24 Surface Chemistry Changes Biology C60 Sayes et al., NanoLet, 2004
Shape Changes Physico-Chemical Properties Wang et al., Materials Today, 2002
Risk is function of both the hazard and the exposure Photos courtesy of Nigel Walker, PhD, National Toxicology Program
Goal of Emerging Technologies Maximize Benefit and Minimize Risk