2. http://www.youtube.com/watch?v=aULBj36yLCQ

3. What safety issues can you think of that need to be considered when introducing a new nano- product? Brainstorm 1

4. What entry points do you think a nano-product might have into the human body? Mark and label this diagram to show your thinking. Brainstorm 2

5. Inhalation: Inhaled particles induce inflammation in respiratory tract, causing tissue damage. Example: Inhalation of silica particles in industrial workers causes “silicosis”. Ingestion: nanoparticles may cause liver damage. Ingested nanoparticles (i.e. for oral drug delivery) have been found to accumulate in the liver. Excessive immune/inflammatory responses can cause permanent liver damage. Entry options for Nano-particles Dermal exposure: Particles may enter the body through the skin. Potential hazards are unknown at present. Other: ocular, wound exposure

6. What sort of Nano-Particles could pass through the Skin? So far we have learnt a bit about how changing the size of particles alters the physical properties. To understand how different nanoparticles will interact with skin we have to learn a little more about the chemistry of the nano- particles. Skin Absorption

7. So lets look at some nano-particles….. CHEMISTRY OF NANO-PARTICLES

9. How this particle interacts chemically is usually “Only Skin Deep” That means the type of chemical groups on the surface of the particle dictate how it will interact with other chemicals. That means for a nano-particle to pass through intact skin it has to be compatible or the chemicals on its surface need have similar SOLUBILITY to the skin its self. So to gain a better understanding we will have to discuss solubility and chemistry in a bit more detail. Chemistry of Nano-Particles

10. Most nano-particles have surface chemicals that fit into one of these three categories. 1 Ionics: The surface has charged ions on it. This would cover most minerals, salts, many water soluble materials and some ionic biomolecules like DNA. 2 Polar: The surface has polar molecules on it. While none of these chemicals are charged they definitely ‘like’ polar solvents such as alcohol. This includes plastics like PVA (wood glue), and biomolecules such as proteins, starch and cellulose. 3 Non-Polar: The surface has Non-polar molecules on it. Non-polar molecules hate water. They have no charged or polar components. They prefer to interact with other non polar substances such as petroleum products, cooking oil, fats and larger molecules such as plastics like polystyrene and polyethylene. Chemistry of Nano-Particles

11. 1Ionics: The surface has charged ions on it. Common table salt - sodium chloride. Each crystal is made up of trillions upon trillions of positively charged sodium ions and trillions upon trillions of negatively charged chloride ions packed into a very big structure called a lattice. The positive and negative ions are held together by what is called an ionic bond Chemistry of Nano-Particles

12. 1Ionics: The surface has charged ions on it. Even though water its self is not ionic, it is able to interact with ionic particles, and is very effective in dissolving most ionic chemicals. http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/molvie1.swf http://www.northland.cc.mn.us/biology/Biology1111/animations/dissolve.html These websites give a nice summary of water dissolving salt. Chemistry of Nano-Particles

13. Water dissolving an ionic compound H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O

14. 2 Polar: The surface has polar molecules on it. Polar molecules are not charged like ionic compounds, but instead have positive and negative ‘poles’. The positive poles of one molecule attract the negative poles of another molecule. This is a bit like a magnet having North and South poles, where the north pole of one magnet attracts the south pole of another magnet. Chemistry of Nano-Particles

15. 2Polar: The surface has polar molecules on it. Polar molecules like other polar molecules (just like magnets like other magnets), but don’t like non-polar molecules. Water is a polar molecule, and so polar molecules tend to dissolve well in water. Chemistry of Nano-Particles

16. 3Non-Polar: The surface has Non-polar molecules on it. Non-polar molecules feel oily or fatty – in fact, fats and oils are two common types of non-polar molecule. Non-polar molecules interact well with other non-polar molecules, but not as well with polar molecules. They tend not to dissolve in water (forming layers), but often dissolve well in non-polar solvents, such as kerosene. Chemistry of Nano-Particles

17. In this prac we will see how well different chemicals penetrate the skin and the intestinal wall. We will use chicken skin and pig intestine. - Why are we interested in how these molecules penetrate the skin and the intestine? What entry points are we simulating? Ingestion: Nanoparticles may be absorbed across the intestinal wall and into the bloodstream. Dermal exposure: Nanoparticles may enter the body through the skin. Investigating Entry Points of Nano-Particles into the Body

18. Recap of Last Lesson Points of entry into the body – Dermal – Inhalation – Ingestion – Cuts, wounds, other openings (eg eye) Types of molecules that can enter the body – Dermal – Ingestion

19. Prac results Using 2-3 dot points describe the results of your prac. Use another dot point to summarise these results.

20. Other points of entry The third major pathway for nano- particles to enter the human body is through inhalation. To investigate this, we need to first investigate the physiology of the lungs.

21. Inhalation of nanoparticles The lungs are one of the vital organs to human life. The major components of the lungs are the two bronchi, which branch into smaller and smaller ‘tubes’ called bronchioles. These tubes terminate at tiny sacs called alveoli.

22. Inhalation of particles – Silicosis and Asbestosis These diseases are both caused by the inhalation of particles from the air. These particles lodge in the alveoli in the lungs, and cause significant damage over time. This alveolar degradation results in shortness of breath, and can lead to lung cancers. Could inhalation of nanotubes cause a new form of this disease?

23. Video – Nigel Holmes discusses the safety implications of new nanotechnologies http://www.youtube.com/watch?v=MT40_oPcycs

24. Your View Now that you have heard some of the information surrounding the safety implications of nano-products, how harmful do you feel they can be before we should stop using them? Should we stop using them if there is any chance that they may cause any harm at all? How about if they cause less harm than standing in the sunshine? Or less harm than breathing in the city air in a place like Beijing or New Mexico? Write a sentence that summarises your view on the topic.

25. Next lesson We would like to add a new section to our major Nano- product assignment. Research some safety or ethical considerations for your Nano- product and describe these in your assignment. This section may be as little as one paragraph, or as large as 500 words, but it must be written in your own words, and the resources you use must be noted in a bibliography. By the end of this lesson you should write at least one relevant dot point that you did not know before, on a slide in the shared powerpoint document.