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Nanoparticles around us – traffic exhausts, forest

fires, volcanoes, accidents, disasters, and

engineered nanoparticles in workplaces

Nanotechnologies

- much ado about nothing

or risks to human health?

Harri Alenius

Research professor

Head, Unit of Immunotoxicology

Finnish Institute of occupational Health


Traffic is a major source of carbon nanoand

other particles


Forest fires release large amounts of carbon and

other nano- and larger particles


The eruption of the Eyjafjallajokull volcano in Iceland:

huge amounts of nanoparticles released


9/11 – WTC Twin Towers in New York


Engineered nanoparticles at workplaces –

the topic of this talk!


ENGINEERED

NANOMATERIALS


Special features of engineered

nanoparticles (ENP)

Small

Reactive

Surprising

Enabling

Huge technological

and financial potential

Risks unknown or

poorly known

1-100 nm


The essence of ENP: Unpredictable

➔ nano ≠ bulk

Bulk gold:

yellow

inert

1 200°C

1 nm gold NP:

blue

low reactivity

200°C

3 nm gold NP:

reddish

catalytic

200°C

Catalytic activity

Cluster diameter (nm)


CARBON NANOTUBES – CROWN JEWELS OF

NANOMATERIALS: EXAMPLES OF CHALLENGES FOR

HUMAN HEALTH PROTECTION

Single walled CNT

Multi walled CNT

The diameter of a SWCNT

about 1 nm, that of MWCNT

~ close to 100 nm, but their

length may be several μm's


Challenges of Nanotechnologies

• In 2007 ~ 7 billion € used for nanotechnology research

globally, 50/50 from public and private sources,

respectively

• Funding of research on health effects of ENP is

modest in many countries – in Europe and the US about

2-3 % of all nanotechnology research

• ENP and nanotechnologies are a challenge to the

EU new chemicals legislation REACH; REACH,

implemented since 2007, does not fully recognize ENP,

and the word 'nano' is not mentioned in REACH now

being modified to correspond the new needs – a new

ENP EU definition been proposed (Nov 19 deadline)


Nano-silver is an important example due to its

microbicidal properties

Cloth cleaner

containing

nanosilver

Cutting board

treated with

nanosilver

Teddy bear for

allergic children

treated with

nanosilver

Nanosilver treated children's

milk bottle brush

Nanosilver treated socks

http://www.nanotechproject.org/inventories/

Nanosilver

treated pillow


A NANOTECHNOLOGY PRODUCT CAN ALSO BE

LARGE – strengthening of concrete with

amorphous silica


Quality of life and social benefits of

nanotechnologies – how to regulate possible

benefits and risks already here?

From Andrew Maynard, Chief scientist of The Project on Emerging Nanotechnologies


ENTRY OF ENP INTO SYSTEMIC

CIRCULATION AND THE BODY

• Routes of ENP into the body:

– Lungs – rapid route to the circulation through

the alveoli, deposition in the lungs

– Nose – axons of olfactory nerve provide a

direct entry into the brain – effects?

– Gastrointestinal tract maybe important for

novel foods, not in the work environment

– Skin may be important in the case of skin

diseases and skin damages – the largest organ

in the body


INJECTION

UK Royal Society & Royal Academy of Engineering

Report on Nanoscience & nanotechnologies (2004)

Altistuminen: lähteet, kohteet, & reitit

DERM


The safety knowledge gap challenging

development of legislation, regulations

Schematic representation of emergence of nanotechnology products in comparison

to generated EHS data (Linkov and Satterstrom: Nanomaterial Risk Assessment and

Risk Management, 2008).


MODELLING

INFLAMMATORY

EFFECTS IN HEALTHY

SUBJECTS


Effects of exposure to metal

nanoparticles


Effects of airway exposure to TiO2 nanoparticles on

pulmonary inflammation in healthy mice

• Titanium dioxide (TiO2) nanoparticles are widely used in

the field of biotechnology, pharmaceuticals and cosmetics

and textile industries in applications such as paints,

coatings, UV protection and photocatalysis

• Characteristics of TiO2 nanoparticles are also altered in

several ways to improve their performance. Properties can

be altered by doping TiO2 with other elements, or by

modifying the TiO2 nanomaterials surface with other

semiconductors.

Aim of our study was to explore inflammatory

changes in the lungs induced by repeated airway

exposure to different type of TiO2 nanoparticles

using mouse and cell models

Rossi EM, et al. Toxicol Sci. 2010 113(2):422-433.

20


Characteristics of particles used in the

present study

6 different particle types were tested

- 3 different commercially available TiO 2

nanoparticles

- 1 on-site generated TiO 2

nanoparticle

- 1 commercial coarse TiO 2

- 1 SiO 2

nanoparticles (coating material)

Characteristics identified:

- Particle size, agglomeration size, surface area, phase structure,

radical formation capacity, Z-potential

Name

Coated nanosized rutile

TiO 2

Nanosized anatase TiO 2 Coarse rutile TiO 2

Nanosized SiO 2 Nanosized rutile TiO 2

Nanosized

anatase/brookite TiO 2

Vendor Sigma-Aldrich Sigma-Aldrich Sigma-Aldrich

Product number 637262 637254 224227

Particle size 10x40nm


Inhalation exposure procedures

Dust generator

(brush)

On-site reactor

Constant production of TiO2 aerosol at the concentration of 10mg/m3

22


Pulmonary inflammation in mouse lungs after TiO2

exposure

12

9

Neutrophils

A= 2 hours exposure

B= 4 days exposure

C= 4 weeks exposure

% of BAL cells

6

3

0

Exposure time

- A B A B C A B A B A B C A B C

nanoSiO2

amorphous

nanoTiO2

+SiO2

rutile

nanoTiO2

rutile

nanoTiO2

anatase

nanoTiO2

anatase

(generated)

coarseTiO2

rutile

• None of the nanoTiO2 preparation tested, other than SiO2 coated

TiO2, elicited pulmonary inflammation in mice !!!

• Exposure to nanoSiO2 did not induce any inflammatory effects !!!

23


Nanoparticles accumulate in pulmonary

macrophage phagosomes in murine lungs

TiO2

TiO2 + SiO2

24


Conclusions

• Nanoparticle induced lung inflammation could not

be explained by the surface area of the particles,

their primary or agglomerate particle size or radical

formation capacity, but is rather explained by the

surface coating.

Our findings emphasize that it is vitally

important to take into account in the risk

assessment that alterations of nanoparticles,

e.g. by surface coating, may drastically

change their toxicological potential.

25


Effects of exposure to carbon

nanotubes


Asbestos exposure induced disorders

Asbestosis is a breathing disorder

caused by inhaling asbestos

fibers. Prolonged accumulation of

these fibers in lungs can lead to

scarring of lung tissue and

diminished breathing capacity.

Signs and symptoms of

asbestosis usually don't appear

until years after exposure.

27


Background

• Needle-like fiber shape of carbon nanotubes have has

been compared to asbestos, raising concerns that

widespread use of carbon nanotubes may lead to

mesothelioma, cancer of the lining of the lungs caused

by exposure to asbestos.

• Mesothelioma is almost exclusively found following

asbestos exposure and mesothelioma is a particle

response unique to fibre-shaped particles.

• Authors hypothesize that the most important

acute response to long MWCNTs, if they were to

behave like asbestos, would be mesothelial injury.

28


Recruitment of inflammatory cells in the peritoneal

cavity after introduction of fibers

Inflammatory response

24 h post -installation

Granuloma response

7 days post -installation

Short fibers

Long fibers

Short fibers

Long fibers

Female C57Bl/6 mice were intraperitoneally instilled with 50 µg of vehicle control, nanoparticulate

carbon black (NPCB), short-fibre amosite (SFA), long-fibre amosite (LFA), two curled/tangled MWNT

samples of different lengths (NTtang1, NTtang2) and two samples containing long MWNTs (NTlong1,

NTlong2).

29


Morphological features of diaphragms of after

particle/fiber exposure after 7 days

Short MWCNT

Sample 1

Short MWCNT

Sample 2

Long amosite

(brown asbestos)

Long MWCNT

Sample 1

Long MWCNT

Sample 2

Poland et al. Nature Nanotechnology. 2008 Jul;3(7):423-8.

30


Inhalation exposure to carbon nanotubes

• Male C57BL6 mice were

exposed (nose-only) to an

aerosol of MWCNT or carbon

black (CB) nanoparticles

(30 mg/m 3 ) for 6 hours

– MWCNT length 0.3-50um

• Lung tissues were collected

and carefully examined 1

day, 2 weeks, 6 weeks and

14 weeks post exposure

31


Subpleural fibrosis in mice after CNT

inhalation

saline aerosol-exposed

Subpleural fibrotic lesion

showing MØ with CNT

CNT exposed mice

2 weeks after inhalation

Ryman-Rasmussen et al. Nature Nanotech. 4(11):747-751 (2009)

32


Discussion

• MWCNT behave as asbestos as they...

– Are deposited at the alveolar level

– Reach the subpleural level after inhalation

– Remain in the subpleura intact for weeks and

stimulate fibrosis (scar formation)

33


Movement of particles through the lung

Long nanotubes

lodge at the

drainage points

and block them

inflammation,

and pathological

changes over

time

Donaldsson and Poland, 2009

pleura = red lines

pleural space containing fluid = between the two membranes

small particles = blue circles

short or tangled nanotubes = black lines

34


EFFECTS IN DISEASE

MODELS


Background

• Evidence exits that individuals with airway allergies

may be more pronounced to show respiratory

symptoms compared to healthy people when exposed

to particulate matter.

• It is important to examine whether the

pulmonary inflammatory responses against

nanomaterials vary depending on the disease

status.

36


Effects of titanium dioxide

particle exposure on allergic

asthma

Rossi E, Pylkkänen L, Koivisto A, Nykäsenoja H, Wolff H, Savolainen

K, and Alenius H. Particle and Fiber Toxicology (revised)


Airway reactivity and airway inflammation is

suppressed after inhalation of TiO2 particles

8

Airway reactivity

to inhaled metacholine

40

30

Eosinophils

*

50

40

IL-13 mRNA

** ***

Penh

6

4

OVA

OVA + nTiO2

PBS

cells / HPF

20

10

0

- nTiO2 fTiO2 - nTiO2 fTiO2

RU

30

20

10

0

- nTiO2 fTiO2 - nTiO2 fTiO2

2

PBS

OVA

PBS

OVA

3

30

MCh (mg/ml)

100

Lymphocytes

IL-4 mRNA

PBS = healthy mice

OVA = allergic mice

cells / HPF

8

6

4

2

**

**

RU

15

10

5

*** **

nTiO2 = nanoTiO2

fTiO2 = fineTiO2

0

- nTiO2 fTiO2 - nTiO2 fTiO2

PBS

OVA

0

- nTiO2 fTiO2 - nTiO2 fTiO2

PBS

OVA

38


Conclusions

• Mice with allergic asthma are not more pronounced to

show respiratory symptoms and airway inflammation

compared to healthy mice when exposed to TiO2

particles.

• Rather, Th2 type pulmonary inflammation and airway

hyperreactivity is dramatically suppressed in mice which

are simultaneously exposed to TiO2 particles.

39


Inhaled Multiwalled Carbon

Nanotubes Potentiate Airway

Fibrosis in Murine Allergic

Asthma

Ryman-Rasmussen P et al. Am J Resp Cell Mol

Biol. Vol. 40, pp. 349-358, 2009


Combined Ovalbumin Allergen Challenge and

MWCNT Inhalation Cause Airway Fibrosis

SAL

OVA

SAL+MWCNT

OVA+MWCNT

PBS = healthy mice

OVA = allergic mice

14 days after exposure

41


Levels of platelet-derived growth factor (PDGF)

and transforming growth factor (TGF)-β1 protein

in BALF 1 day after MWCNT inhalation.

PDGF+TGFΒ1=FIBROSIS

42


Conclusions

• Study suggests that airway fibrosis resulting from

combined ovalbumin sensitization and MWCNT inhalation

requires PDGF, a potent fibroblast mitogen, and TGF-β1,

which stimulates collagen production.

Individuals with pre-existing allergic inflammation

may be susceptible to airway fibrosis from inhaled

MWCNT.

43


General Conclusions

• Different type of particles may elicit drastic

differences in the inflammatory response

• Surface coating may have critical effect to the

toxicity of the particles

• Underlying disease influence significantly to

the health effects of particles. We can not study

only healthy people

44


THANK YOU FOR

YOUR ATTENTION!!

45

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