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Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
Nanotubes – Toxicity Compared To Asbestos2
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Nanotubes – Toxicity Compared To Asbestos2

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  • 1.  
  • 2. Nanotubes : As Toxic As Asbestos? By Ted Heinrich
  • 3.
    • Brief overview of Asbestos and Related Diseases.
    • Methods of Research of Carbon Nanotubes
    • Background of Carbon Nanotubes (CNTs)
    • Compare Physical and Chemical Properties of Asbestos and CNTs
    • Hypothesized Mechanisms of Fiber Carcinogenicity
    OUTLINE
  • 4.
    • Abundant
    • Flame Retardent
    • High tensile strength and flexibility
    • Electric and Acoustic Insulator
    • Resistant to Acids and Bases
    1. Brief Overview of Asbestos
  • 5. Effects of Asbestos on Lung Tissue
    • Benign Pleural Plaques
    • Pleural Effusion
    • Asbestosis
    • Lung Cancer
    • Mesothelioma
    • Can take 30 – 50 yrs to develop
  • 6. 2. Methods of Research of Carbon Nanotubes
    • Existing Data comes from exposure studies
      • In Vitro (cell cultures)
        • Mesothelial Cells
        • Lung Cells
        • Other Cells
      • In Vivo (animals)
        • Inhalation
        • Aspiration
        • Instillation
      • On Humans
        • Volunteer Studies
        • Epidemiological Studies
    • Interest in comparing CNT to Asbestos as a means of projection
  • 7. 3. Carbon Nanotubes (CNT) 1939 – First commercial versions of TEM produced by Siemens 1952 – First documented (TEM) evidence of nano-sized carbon filaments was published in Journal of Physical Chemist in Russia [1] 1991 – MWCNT brought to prominence by Iijima in 1991 in Nature 1993 - SWCNT discovered
  • 8.  
  • 9. CNT attractive because…
    • Application in miniaturizing electronics
    • High strength to weight ratio
    • High thermal stability
    • Resistance to chemicals
    • High surface area
    • … increased chance of contamination during synthesis
  • 10. Synthesis
    • Two components needed
      • Carbon Source
      • Energy Source
    • Carbon Arc Discharge
    • Laser Abbalation
    • Chemical Vapor Deposition
    • Water assisted CVD
  • 11. 4. Comparing Physical and Chemical Parameters of Asbestos and Carbon Nanotubes PHYSICAL and CHEMICAL PARAMETERS ASBESTOS CARBON NANOTUBES Shape Size Chemistry Surface Reactivity Biopersistence
  • 12. PHYSICAL and CHEMICAL PARAMETERS ASBESTOS CARBON NANOTUBES Shape More organized Bundles Or Single Fibers Aggregates, Ropes, Clumps up tp 3 μ m in diameter Size Chemistry Surface Reactivity Biopersistence
  • 13. Shortest Length SW Cycloparaphenylene Shortest DiameterSW Grown inside MWCNT Longest SW 18.5 cm PHYSICAL and CHEMICAL PARAMETERS ASBESTOS CARBON NANOTUBES Shape More organized Bundles Or Single Fibers Aggregates, Ropes, Clumps up tp 3 μ m in diameter Size ( diameter x length) Chr ( 25-100nm x 1- 50 μ m) Amo (100-200nm x 1-30 μ m) SW ( .4-3nm x 3Å-18.5cm) MW ( 2-200nm x 1nm-3cm) Chemistry Surface Reactivity Biopersistence
  • 14.
    • ROS – Reactive Oxygen Species
    • Causes oxidative stress via “redox signaling”
      • Lipid peroxidation
      • Oxidation of amino acids
      • Metabolic changes
      • DNA damage
    PHYSICAL and CHEMICAL PARAMETERS ASBESTOS CARBON NANOTUBES Shape More organized Bundles Or Single Fibers Aggregates, Ropes, Clumps up tp 3 μ m in diameter Size ( diameter x length) Chr ( 25-100nm x 1- 50 μ m) Amo (100-200nm x 1-30 μ m) SW ( .4-3nm x 3Å-18.5cm) MW ( 2-200nm x 1nm-3cm) Chemistry Presence of metals May also contain metals Surface Reactivity Biopersistence
  • 15. Hydrophillic Amphiboles, once inside, adsorb phospholipids and proteins - complex coat of apatite minerals and aggregates (possible further research with CNT) PHYSICAL and CHEMICAL PARAMETERS ASBESTOS CARBON NANOTUBES Shape More organized Bundles Or Single Fibers Aggregates, Ropes, Clumps up tp 3 μ m in diameter Size ( diameter x length) Chr ( 25-100nm x 1- 50 μ m) Amo (100-200nm x 1-30 μ m) SW ( .4-3nm x 3Å-18.5cm) MW ( 2-200nm x 1nm-3cm) Chemistry Presence of metals May also contain metals Surface Reactivity Hydrophilic Hydrophobic (unless functionalized) Biopersistence
  • 16. PHYSICAL and CHEMICAL PARAMETERS ASBESTOS CARBON NANOTUBES Shape More organized Bundles Or Single Fibers Aggregates, Ropes, Clumps up tp 3 μ m in diameter Size ( diameter x length) Chr ( 25-100nm x 1- 50 μ m) Amo (100-200nm x 1-30 μ m) SW ( .4-3nm x 3Å-18.5cm) MW ( 2-200nm x 1nm-3cm) Chemistry Presence of metals May also contain metals Surface Reactivity Hydrophilic Hydrophobic (unless functionalized) Biopersistence Short - Not Long - Amosite is Tangled – length dependent [2] Long/Singlet - ???
  • 17. Frustrated Phagocytosis
    • Pro-Inflammatory
      • Formation of Granuloma
      • Scarring
      • Fibrosis
      • Mutation
  • 18. Clearance Mechanisms
    • Nose and Tracheobronchial Region
      • The Mucociliary Escalator (dependent upon Aerodynamic Diameter of fiber)
    • Alveola
      • Macrophagal (White Blood Cell) Phagocytosis
    • Lung and Lung Tissue
      • Dissolution / Breakage (CNT can persist in 4.5 pH for 2 months)[3]
    • Translocation
      • Pass through alveolar wall into interstial fluid and lymph
  • 19. 5. Hypothesized Mechanisms of Fiber Carcinogenicity [4]
    • Free Radical Generation
    • Physical Interference with Mitosis
    • Stimulation of Target Cell Proliferation
    • Persistent Chronic Inflammation
  • 20. References
    • [1] Endo M, et al. Pyrolytic carbon nanotubes from vapor-grown carbon fibers. Carbon 1995;33:873-81
    • [2] Donaldson K, et al. Asbestos, carbon nanotubes and the pleural mesothelium: a review of the hypothesis regarding the role of long fibre retention in the parietal pleura, inflammation and mesothelioma. Particle and Fibre Toxicology 2010, 7:5
    • [3] Liu X, et al. Targeted removal of bioavailable metal as a detoxification strategy for carbon nanotubes. Carbon 2008;46:489-500
    • [4] Sanchez V, et al. Biopersistence and potential adverse health impacts of fibrous nanomaterials: what we have learned from asbestos? Wiley Interdiscip Rev Nanomed Nanobiotechnol. 2009;1(5):511-529
  • 21.  

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