Nanotechnology: Toxicological considerations. Terry Tetley

Transcription

1 Nanotechnology: Toxicological considerations. Terry Tetley Lung Cell Biology Section of Pharmacology and Toxicology National Heart and Lung Institute Imperial College

2 AIR POLLUTION Friday 5 to Tuesday 9 December 1952 Estimated that up until 8 December 4,000 people had died prematurely and 100,000 more were made ill. Recent research suggests that the total number of fatalities was considerably greater, at about 12,000

3 Effects of ambient environmental particulate air pollution on cardio vascular health Increases in PM2.5 from a few hours up to weeks causes increased ischemic heart disease events and hospitalisation Increased myocardial infarct, both acute and chronic exposure, and increased risk of death from myocardial infarct with chronic exposure Raised blood pressure Reduced heart rate variability Development (in previously healthy individuals) and acceleration of atherosclerosis Deaths form heart attacks Deaths from strokes

4 Effects of ambient environmental particulate air pollution on respiratory health. Increased coughing and wheezing, particularly children Increased use of medication for asthma Attacks of asthma in patients with pre-existing asthma, especially children Exacerbation of chronic obstructive pulmonary disease (COPD) and associated increased hospital admissions (doubling for each 10mg/m3 increase in PM2.5) and increased rate of decline in FEV1 Reduced growth in lung function in children Increased risk of microbial infection Deaths from cancer and other respiratory causes Prenatal exposure relates to reduced lung function/function and increased airway hyperresponsiveness, airway inflammation, mucus secretion

5 AIR POLLUTION: 1952 SMOGS MIX OF SOOT AND FOG LONDON, DECEMBER 1952 Today: Deisel exhaust particles are <100nm in diameter

6 ENGINEERED NANOPARTICLES? EFFECTS UNKNOWN

7 Nanomaterials Nanoparticles/nanomaterials are structures which have at least one dimension of 100nm or less. Include nanofibres, nanotubes as well as spherical structures with a diameter of <100nm.

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9 Why use nanoparticles? When materials enter the nano-range, their properties alter from that of their micron-sized equivalents. Nanoparticles have enhanced thermal, magnetic, electrical and optical properties As size decreases, the surface area:volume ratio increases The surface is more reactive, improving drug labelling

10 Sugar cube analogy Nanoparticle: Less than 100nm in one dimension 1 1cm 3 sugar cube, 1 x nm 3 cubes 6.4 x nm 3 cubes Nanoparticles can be natural, anthropogenic or manufactured

11 Nanoparticle use, number of products listed as containing nanoparticulate material

12 Over 1300 products- Use of engineered nanoparticles Medicine Engineering Construction industry Cosmetics Clothing Food Sports goods Diagnosis, treatment Antibacterial sprays and medical products Low calorie food products Sports goods Clothing Cosmetics, sun cream

13 Nanoparticle use

14 2002 Publication of Prey, a novel by Michael Crichton. A medic with a vivid imagination. The book describes how an artificial swarm of nanorobots develop intelligence and threaten their human inventors. The novel generated concern within the nanotechnology community that the public perception of nanotechnology might be affected, creating fear of a similar scenario in real life.

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16 Nanotoxicology Following concerns raised by Prince Charles and others, the Royal Society and Royal Academy of Engineering published a report, Nanoscience and nanotechnologies: opportunities and uncertainties, July Nanotoxicology emerged as a subject in its own right.

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18 Risks and concerns Perceived risks: Occupational exposure Exposure during use/application/disposal Accidental exposure Concerns: Safety: Potential adverse effects via inhalation- lungs, dermal-skin, ingestion-gut, systemic delivery (e.g. intravenous administration) Susceptible subpopulations Implications for society

19 Deposition and impact of inhaled nano-sized ambient air pollution particles

20 Structure of the lung

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22 In vitro alveolar models TT1 cells - Transformed human alveolar epithelial type-1-like cell (TT1) model. Kemp, S. J. et al Am. J. Respir. Cell Mol. Biol AT2 cells - Primary alveolar epithelial type 2 cells, isolated from normal regions of human lung tissue. AM Alveolar macrophages lavaged from human lung tissue

23 Nanoparticle exposure models Human lung cell monolayer Alveolar epithelium, alveolar macrophages, fibroblasts, Incubated with nanoparticles Up to 24 hours (acute) Medium Pro-inflammatory mediators Cytokines, chemokines Cells Particle uptake, Viability, Reactive oxygen species

24 ATII cell uptake of 50nm polystyrene latex nanoparticles Carboxyl Neutral 4hr 24hr

25 ATI cell uptake of 50nm polystyrene latex nanoparticles Carboxyl Neutral 4hr 24hr

26 ATI cell uptake of 50nm and 100nm polystyrene latex nanoparticles 50nm 100nm MFI MFI Time (mins) Time (mins) Amine-modified Carboxyl-modified Unmodified

27 Particle cytotoxicity 50nm Nanoparticles 100nm Nanoparticles % Viability Dose ( g/ml) 100 Unmodified Amine 80Modified Carboxyl Modified 60 % Viability Dose ( g/ml) Unmodified Amine Modified Carboxyl Modified

28 Hopping probe ion conductance microscopy of AT1 epithelial cells exposed to carboxyl-modified and amine-modified 50nm latex particles for 4 hours. A Carboxyl-modified NP E Amine-modified NP

29 Hopping probe ion conductance microscopy of AT1 epithelial cells exposed to carboxyl-modified and amine-modified 50nm latex particles for 4 hours. A Carboxyl-modified NP E Amine-modified NP Ruenraroengsak et al. Respiratory epithelial cell cytotoxicity and membrane damage (holes) caused by amine-modified nanoparticles, Nanotoxicology 2012, 6:94-108

30 Cellular fate of nanoparticles 500nm

31 Engineered nanoparticles/nanomaterials Carbon-based fullerenes, carbon nanotubes, wires, graphene etc Metals gold, silver Metal oxides titanium dioxide (self cleaning surfaces), zinc oxide (both in sunscreens), copper oxide, cerium oxide (in deisel to reduce particle numbers) Organic/soft as synthesised for drug delivery Quantum dots <10nm diameter

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33 ARGYRIA was he born with a silver spoon in his mouth?

34 Medical applications of silver nanoparticles

35 Differences in cellular uptake of gold and silver nanoparticles Phagocytic alveolar macrophage cell exposure (4 hr) 1 μg/ml 10 μg/ml 25 μg/ml 50 μg/ml Au 5 nm Au 15 nm Does this impair phagocytic activity? eg during bacterial infection

36 Differences in cellular uptake of gold and silver nanoparticles Alveolar epithelial Type 1 cell exposure (4 hr) 1 μg/ml 10 μg/ml 25 μg/ml 50 μg/ml Au 5 nm Au15 nm

37 Differences in cellular uptake of gold and silver nanoparticles Alveolar epithelial type 2 cell exposure (4 hr) 1 μg/ml 10 μg/ml 25 μg/ml 50 μg/ml Au 5 nm Au 15 nm

38 Effect of Ag on ATI cells not cytotoxic, but stimulate pro-inflammatory mediators % Cell Viability nm Ag Spheres nm Ag Spheres 300 Ag Nanowires Ag ( g/ml) Ag ( g/ml) IL-8 (pg/ml) nm Ag Spheres 50nm Ag Spheres Ag Nanowires

39 Silver spray products NAME DESCRIPTION CODE Colloidal Silver Spray Used as cosmetic spray, dermatologic applicatio S1CS Schudheo Used to prevent unpleasant odors in shoes S3CS Skin and Body Protectant Used for skin enhancement S5CS General Hygiene Antiseptic Used to clean skin S6CS Mesosilver Dermal application as antifungal spray. S7HS Colloidal Silver Nasal Spray Used to improve breathing S8HS Sovereign Silver Used as dietary supplement S9HS Smelly Shoe Spray Used to prevent unpleasant odors in shoes S10OS Silver Care Used as cosmetic for skin protection S11CS Ultra Colloidal Silver Spray Used orally as a dietary supplement S12HS Nanofix Used to clean surfaces S13OS Nan Health Silver Silver 22 Slide: courtesy Gedi Mainelis, Rutgers Used orally to prevent diseases (no built-in sprayer) Used orally as a dietary supplement (no built-in sprayer) S2HO S4HO

40 SILVER CONTAINING PRODUCTS Smelly Shoe Spray MesoSilver Nanofix Silver Nasal Spray 3.86 µg/ml Colloidal Silver 15.86µg/ml Colloidal silver 1.21µg/ml silver µg/ml silver Isopropanol Water Deionized water Deionized water Peppermint essential oil S1 S2

41 Zinc containing Products DermaZinc Therazinc 505.4ug/ml Pyrithione Zinc SDA-40 Alcohol Isopropyl Myristate SLS needles Undecy lenic acid Z1 5115µg/ml Zinc Vegitable Glycerin Peppermint Oil Clovebud oil Echinacea extract Menthol Z2

42 Effect of silver products on type-1 epithelial cell viability 24 hr exposure particle concentration micrograms/ml

43 Effect of zinc products on Type -1 epithelial cell viability 24 hour exposure particle concentration micrograms/ml

44 Nanoparticles can induce reactive oxygen species in alveolar cells T=4h TT1 AT2 MAC a e i m q u Control DOSE b f j n r v c g k o s w d h l p t x +NPs NPs +NAC +NPs NPs+NAC +NPs NPs+NAC Co-application of N-acetylcysteine prevents induction of ROS in epithelial cells, but has no effect on macrophages

45 Silver-induced genotoxicity Induction of double-stranded DNA breaks nt Ag (μg/ml) H2A.X GAPDH 10 *** H2A.X / GAPDH ** 0 nt C ( g/ml)

46 Collaborative in vivo studies show that inhalation of silver causes acute: Inflammation Reduction in elastance/elastic recoil Reduced lung surfactant function

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48 Qualities of graphine: A thin flake of carbon, one atom thick Thinnest, strongest material ever Conducts electricity as effectively as copper Conducts heat better than all other materials Almost completely transparent, yet so dense, not even helium can pass through it.

49 Nanowire 1/10,000th Human hair 70 m Carbon nanotubes Multi-walled and single walled Less than 100nm diameter. Can reach many micrometres in length.

50 Use of carbon nanotubes, wires, fibres: Engineering Electronics Construction industry Cosmetics Clothing Sports goods Medicine

51 Bhirde,A.A. et al. ACS Nano 3, (2009).

52 -EGF +EGF Bhirde,A.A. et al. ACS Nano 3, (2009).

53 Carbon nanostructures may exist in many formats including tubes, wires and fibres Crocidolyte asbestos Chrysotile asbestos

54 Inhalation of asbestos can cause lung disease ASBESTOSIS NORMAL LUNG LUNG CANCER & MESOTHELIOMA

55 Transmission EM of TT1 cell uptake of 200nm MWCNTs TT1-200nm 4VP CNTs, T=24h

56 TT1-700nm 4VP CNTs, T=24h

57 Effect of long and short multiwalled carbon nanotubes on human alveolar cells SHORT MWNTs LONG MWNTs

58 Effect of long and short MWCNT on cell viability (MTT) With and without Curosurf (pig surfactant) CNT A CNT B CNT C CNT D CNT E m Long) 3-5 m (medium) m (short) Viability (% of Control) TT1 cells * * ** *** *** *** *** *** CNT sample ( g/ml) ** *** *** short 100 CNT A90 CNT B80 CNT C70 CNT D60 CNT E Viability (% of Control) AT2 cells * *** ** CNT sample ( g/ml) C C C C C AM cells Viability (% of Control) * * *** *** *** CNT A CNT B CNT C CNT D CNT E long CNT sample ( g/ml)

59 TT1 cells 2000 IL-8 (pg/ml) IL-8 (pg/ml) * *** Purity 0 IL-8 release from TT1, AT2 and AMs exposed to short and long MWCNTs IL - 8 (pg/ml) *** TT1 cells AT2 cells TT1 cells *** *** 1000 * ** *** ** ** * * 500 * *** % % 97% Purity 48% 74% 97% 48% Purity 97% 74% Purity 48% 97% 74% Purity 97% 48% 97% 74% 97% 97% Purity 97% 48% 74% 97% 97% 97% 97% Purity 48% 74% 97% Length 97% 0.6 m 3 m 20 m m Length Length 0.6 m 20 m 3 mlength 20 m 20 m Length 0.6 m20 m Length 3 m0.6 m 20 m 3 m 0.6 m 20 m 3 m 0.6 m Length 20 m3 m 0.6 m 20 m 3 m 20 m 3 m Length CNT sample ( g/ml) 20 m 0.6 m 3 m 20 m CNT sample ( g/ml) TT1 cells IL-8 (pg/ml) IL - 8 (pg/ml) * * *** IL - 8 (pg/ml) IL - 8 (pg/ml) TT1 cells AT2 cells AT2 cells Purity AT2 cells AMs AMs AMs *** *** g/ml *** * 0.1 *** *** *** 0 0 *** *** *** *** 10 *** *** *** * *** 50 * *** ** * ** *** * * * * * 2000 *** 6000 *** 4000 * ** ** * * CNT sample CNT ( g/ml) sample CNT ( g/ml) sample CNT ( g/ml) sample CNT sample ( g/ml) ( g/ml) CNT sample CNT ( g/ml) sample ( g/ml) CNT sample ( g/ml) *** *** 8000 *** Same pattern of response for IL-6 and MCP1 release Shorter CNTs are more reactive with epithelial cells. Longer CNTs are more reactive with macrophages. IL - 8 (pg/ml) IL - 8 (pg/ml) m

60 Frustrated phagocytosis is a common feature of mesothelioma

61 Frustrated phagocytosis of carbon nanotubes by human alveolar macrophages

62 Effect of MWCNT of different lengths on human lung fibroblast viability (n=4 subjects)

63 Effect of MWCNTs of different lengths on soluble collagen release by human lung fibroblasts N=4

64 Development of granuloma and mesothelioma following injection of MWCNT into peritoneal cavity

65 Can Carbon Nanotubes cause fibrosis? Shvedova, A.A et al. Am J Physiol Lung Cell Mol Physiol Oct;295(4):L Ma-Hock,L. et al. Toxicol. Sci. 112, (2009)

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67 IL-6 pro-inflammatory cytokine release by AT1 cells exposed to silver nanoparticles 20nm 110nm Ag PVP Curosurf Curosurf g/ml Ag 67

68 SP-A SP-D

69 Binding of surfactant proteins A and D to MWCNTs MWCNTs Long (>15 m) Short (<3 m) KDa SPA binding KDa 43 SPD binding

70 Intracellular AT2 SP-A and SP-D following exposure to pristine Arkema MWNTs AR MWCNT (µg/ml) NT β-tubulin SpD SpA

71 Verdict Some nanosized materials may have adverse health effects They need to be tested, safety procedures need to be put into place Mercer et al, Particle and Fibre Toxicology, 2013 epub ahead of print

72 MRC-HPA Centre for Environment and Health Imperial College London THANK YOU