TLO 2: What nanotechnology is in relation to human physiology

1. TLO 2: What nanotechnology is in relation to human physiology

2. DNA strand 2.5 nm Bacteria 2.5 um Rain Drop 2.5 mm Scale: A Magnified Look at Nano Objects x 103 x 103

3. Carbon Tube 1.0 nm Human Hair 100 um House 10 m Scale: A Magnified Look at Nano Objects x 105 x 105

4. Platinum 10 nm hex Blood capillary 5-10 um diameter Scale: A Magnified Look at Nano Objects x 103

5. FePt icosahedral 1.0 nm Red and white blood cells 6 - 10 um Scale: A Magnified Look at Nano Objects x 103

6. Zinc Oxide Wire 3 nm dia. X 80 nm Virus 20 to 250 nanometers in Human Cilia 2 to 20 um Scale: A Magnified Look at Nano Objects

7. TLO 3: Human exposure to nanomaterials

8. Toxicity • Nano-particles can enter the body by the following routes of entry (ROEs): • Inhalation • Skin contact • Skin absorption • Ingestion • Injection • Ocular • Transplacental good vs. bad  can cause harm or can be effectively used if properly controlled.

9. Routes of Entry: Inhalation • Important exposure route • Breathing is a necessity • Lungs extremely vulnerable to chemical agents • Substances directly affect lungs • May pass through lung tissue into the bloodstream YouTube - Breathing Commercial

10. Routes of Entry: Inhalation (continued) NP of 35nm enter nasal passage and travel to the brain through olfactory nerve

11. Routes of Entry: Inhalation (continued) Blood Alveoli CO2 O2 Blood Capillary Blood-brain barrier: limitation on size & shape of molecule. NP of 50 nm can enter the brain through sensory nerves NP of 1 nm pass through alveoli into blood

12. Routes of Entry: Skin Contact and Absorption • Skin is body’s largest “organ” • Surface area • 2 square meters • Thickness • 0.5 mm eyelid • 4 mm on palm of hand or sole of the foot

13. Routes of Entry: Skin Contact and Absorption(continued) • Direct contact with skin and eyes • Chemicals may directly injure the skin • Corrosives can destroy cells • Dermatitis is an irritation or inflammation

14. Routes of Entry: Skin Contact and Absorption(continued) • Chemicals may pass through the skin into the bloodstream where they are transported • Skin absorption is enhanced by: • Abrasions and cuts • Heat • Moisture

15. Routes of Entry: Skin Contact and Absorption(continued) • Passive diffusion through outer surface • Nonpolar compounds dissolve in and diffuse through the lipid material

16. Routes of Entry: Skin Contact and Absorption(continued) • Absorption through the eye • Airborne chemicals can dissolve in its moist surface • Then be carried to the rest of the body through the bloodstream • Eye does not seal air tight in skull • Capillaries are very close to the surface of the eye

17. Routes of Entry: Ingestion • Generally least significant route of exposure at a site • Exposure can occur: • Deliberately (although unlikely) • By chewing gum or tobacco • By drinking, eating, smoking cigarettes, and applying cosmetics on site

18. Routes of Entry: Injection • Chemicals are introduced into the body through puncture wounds • Contaminated sharp objects • Miss-handling • Breakage • Slipping

19. Trans-Placental • Maternal blood flow circulates in the placenta • Chemicals in the blood flow have the potential to affect the unborn fetus • Resarch has shown: • Increased inflammatory response • Translocation to target organs • Allergic asthma like symptoms • Aggravate symptoms of pneumonia • Cardiac effects - 2 days later

20. Myoglobin • Binds molecular oxygen (O2). • Found in muscle tissue. • Intracellular storage site for O2.

21. Hemoglobin • Binds molecular oxygen (O2). • Found in erythrocytes. • Molecular carrier for O2 to tissues.

22. Toxins • Interfere with O2 adsorption to Fe. • Limit open/close of heme protein. • Cd, Pb, As.