Fate, Transport, and Toxicity of Nanoparticles in the ...

1 Fate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Fate, transport , and Toxicity of Nanoparticles in the EnvironmentSteven J. OIdenburg, Thomas K. DarlingtonnanoComposix, Inc., San Diego, CATonya Savage and Mitch BogleAFOSR, Eglin AFB, FLFate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Talk OutlineNanotechnology and NanotoxicologyChallenges of Nanotoxicology ResearchNanoparticles for Environmental StudiesTransport of Benchmark NanoparticlesTransport of Aluminum NanoparticlesFate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 NanotechnologyResearch and technology development at the atomic, molecular.

2 Or macromolecular levels using a length scale of 1-100 nanometers in any dimension. EPA Nanotechnology White PaperFebruary 2007 Fate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Risks Associated with NanotechnologyNanotechnology has emerged as a growing and rapidly changing field. New generations of nanomaterialswill evolve, and with them new and possibly unforeseen environmental White Paper on NanotechnologyFebruary 2007 Fate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Environmental Nanotoxicology Determine the impact of manufactured nanomaterialson the environment Monitor the fate and transport of Nanoparticles in soil, water, and the atmosphere Understand the effect of Nanoparticles on plants, micro-organisms, and aquatic species Once hazards have been identified.

3 Propose remediation techniques that will minimize environmental impactFate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Challenges#1: Size, Shape and Surface Dependent Properties Nanostructures of zinc oxide Wang ZL, Materials Today, June 2004 , transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Challenges#2: Size Dependent Toxicity20 nm diameter TiO2particles have a much greater pulmonary Toxicity than pigment-grade TiO2particles (>10X larger) with the same composition (Bermudez, E., et al., Toxicol.)

4 Sci. (2004) 77, 347)Individual 26 nm diameter polytetrafluoroethene (PTFE) particles are toxic to rats as individual but not as agglomerated particles. (Oberd rster, G., et al., Inhal. Toxicol. (1995) 7, 111)Multi-walled carbon nanotubes are more proinflammatory when compared to ultrafine carbon black particles on an equivalent mass dose metric. (Shvedova et al. Am. J. Physiol. Lung Cell Mol. Physiol. (2005) 289, L698) Fate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Challenges#3: Aggregation Dependent Properties2000 Nanoparticles dispersed(diameter = 10 nm)2000 Nanoparticles aggregated (aggregate size = 100 nm)Fate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Initial Study Goals Understand transport of aluminum Nanoparticles in sand and soil.

5 Study nanoparticle benchmark particles with monodisperse sizes and well defined surface chemistry. Compare benchmark particle transport to aluminum nanoparticle transport (aggregated Nanoparticles with a dynamic surface chemistry). Measure nanoparticle induced Toxicity in plants and aquatic speciesFate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Gold and silver nanoparticle benchmark materials Well controlled size and shape Colorimetric aggregation signature Surface chemistry can be easily modified ICP can trace to PPB level Gold is non-toxic, silver is toxicFate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24.

6 2007 The optical properties of gold and silver change dramatically when the dimensions of the material are reduced below 100 nm. From Kelly et. al, J. Phys. Chem B, 107, 668. Nanoparticle Characterization:Dark Field Microscopy & Plasmon ResonanceFate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Nanoparticle Characterization:Dark Field Microscopy80 nm Gold Colloid60 nm Silver ColloidFate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Nanoparticle Characterization:Dark Field MicroscopyDark field images of (a) 80 nm diameter gold particles (b) soil sample (c) gold Nanoparticles and soil samples mixed.

7 Fate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Soil Analysis After Transport40 nm Gold Nanoparticles interact with specific soil componentsFate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Nanoparticle transport Experimental Setup Syringe pump delivery of particles and precise flow rate Glass column to hold transport matrix In line flow cell detection with HP8453 UV-VisFate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 transport of 19 nm Gold in VolumesC/C0 Sample 1 Sample 2 Sample 3 Sample 4 Tracer DyeNanoparticle flow through a 7 cm sand (60 mesh) column loaded with g of sand at a rate of mL / minute.

8 Fate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 transport of Gold Particles in VolumesC/Co4 nm Gold (THPC)19 nm (Citrate)43 nm (KCarbonate)86 nm (KCarbonate)190 nm (Citrate) Nanoparticle flow through a 7 cm sand (60 mesh) column loaded with g of sand at a rate of mL / minute. Fate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 transport of Gold Particles in Soil19 nm citrate stabilized gold Nanoparticles flowing through a 7 cm soil column (Eglin AFB soil sample). (mL)C/C0 Fate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 transport of Gold Nanoparticles in Sand Low affinity of gold particles for sand: consistent with negative surface charge of both sand and gold No effect of size on particle mobility in the range tested (4-190 nm) Surface properties determine transport characteristics Gold Nanoparticles interact with soil components.

9 Fate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Bulk Aluminum ToxicityAluminum in bulk form is generally regarded as safe: Oral little Toxicity on the order of grams Dermal minimal Inhalation on the order of nuisance dust Systemic suggested link with Alzheimer's DiseaseFate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Nanoaluminum ToxicityToxicity of nanoaluminum is under investigation: Nanoaluminum readily internalized into cell lysosomes Evidence that unreacted nanoaluminum is more toxic than aluminum oxide (in-vitromodel A549 cells) Possible mechanism is the release of heat or H2gas during oxidation once the Nanoparticles are inside the cells.

10 Flake shaped nanomaterials more toxic than spherical. Comparable Toxicity to that of quartzFate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 Aluminum Nanoparticle Characteristics 50 nm aluminum particles from Nanotechnologies, Inc. (NT50 Austin, TX). Supplied as dried gray powder Average Grain Size (TEM): 44 18 nm DLS: Hydrodynamic Radius = 340 210 nm Zeta Potential: +44 mV Solution prepared using probe sonication and degassed M water. 100 ppm solutionFate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 DLS vs TEM: Aluminum NanoparticlesTEM of aluminum Nanoparticles :Grain Size: 44 18 nmDLS of aqueous suspension of aluminum Nanoparticles : 340 210 nmFate, transport , and Toxicity of Nanoparticles in the environment , JSEMMay 24, 2007 transport of Aluminum in VolumesC/C0 Nanoparticle flow through a 7 cm sand (60 mesh) column at a rate of mL / minute.