Safety

1. SAFETY
• Accumulation of a nanoparticles within the body can
occur due to lack of degradation or excretion.
• Many nanoparticles are not biodegradable.
Very little is understood about possible health
effects of nanoparticle exposure

2. Particle Scale
Ultrafine Respirable
Nanoparticles
PM 10
PM 2.5
1 nm 10 nm 100 nm 1 mm 10 mm

3. Definitions- Particle Size
• Nano = Ultrafine = < 100 nm (Conventional)
• Nano = <10 nm (suggested by unique quantum and surface-specific
functions)
• Fine = 100 nm - 3 mm
• Respirable (rat) = < 3 mm (max = 5 mm)
• Respirable (human) = < 5 mm (max = 10 mm)
• Inhalable (human) = ~ 10 - 50 mm

5. Potential human hazards for nanoscale particulates.
Inhalation: Inhaled particles induce
inflammation in respiratory tract,
causing tissue damage. Example:
Inhalation of silica particles in
industrial workers causes “silicosis”.
Dermal exposure: Particles may enter
body through the skin. Potential
hazards are unknown at present.
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 cause
permanent liver damage.
Other: ocular, ….

6. 6
Nanoparticle Toxicity
Nanoparticles affect biological behaviour at cellular, subcellular, protein,
and gene levels

7. Possible Health Effects
Inhalation
Pulmonary inflammatory reaction
– Persistent inflammation is likely to lead to diseases such as
fibrosis and cancer. Thus it is important to control
inflammation. This can be done if we can:
- (i) determine the critical dose of particles that initiates
inflammation and
- (ii) set exposure limits, according to the relevant metric, so that
such a dose cannot be reached within a lifetime exposure
scenario.

8. NP’s Deposit Very Efficiently in the
Alveolar Region

9. LUNG DEPOSITION OF CARBON NANOTUBES
Optical micrograph of lung tissue from a rat exposed to single-wall
carbon nanotubes (1 mg/kg) 1 week post exposure. Note
the early development of lesions surrounding the instilled
SWCNT (arrows) and the nonuniform, diffuse pattern of
single-wall carbon nanotube particulate deposition in the lung
(X 100).
Low-magnification micrograph of lung tissue from a rat
exposed to single-wall carbon nanotubes (1 mg/kg) at 1 month
postinstillation. Note the diffuse pattern of granulomatous
lesions (arrows). It was interesting to note that few lesions
existed in some lobes while other lobes contain several
granulomatous lesions—and this was likely due to the
nonuniform deposition pattern following carbon nanotube
instillation. Magnification X 20.
Higher magnification optical micrograph of lung tissue from
a rat exposed to single-wall carbon nanotubes (1 mg/kg) at 1
month postinstillation exposure. Note the discrete, multifocal
mononuclear granuloma centered around the carbon
nanotube material (arrows). Magnification X 400.
D. B. Wahrheit et. al. Toxilogical Sciences 77, 117-125 (2004)

11. NConcerns about granulomas and fibers.
NTs are totally insoluble and probably one of the most
biologically nondegradable man-made materials.Determining how
the NT-induced granulomas progress would require a longer-duration
study with this biopersistent material.
Fibers are generally of more health hazard than other forms of
particulates. It is well established that the pathogenicity of a
fiber in the lungs directly correlates with its biopersistency.
Granulomas (miscropic nodules), consisting of particles, live and
dead cells, and debris and could impair cellular and physiological
(gas exchange) lung functions and give rise to fibrosis, more
defined nodules, and other lesions.

12. Control of Nanoparticles
Exposure by inhalation
- Filtering respirators or air supplied
respirators may be used as a last
option to control exposure to
nanoparticles.
- Probably the efficiency will be high for
all but the smallest nanoparticles (less
than 2 nanometers).
- The respirator must fit properly to
prevent leakage. The white powder around the
nostrils shows that this mask
did not have a tight fit.

13. Ingestion
Possible Health Effects
Nanoparticles can be swallowed and therefore available for transfer to other
body organs via the gastro-intestinal compartment.
Little is currently known about the health effects of nanoparticles on the liver
and kidneys as well as the correct metric for describing the nanoparticle dose
in these organs.
Another area which merits further research is the transfer of nanoparticles
across the placenta barrier. Exposure to nanoparticles during the critical
window of fetal development may lead to developmental damage in the
offspring.

14. Control of Nanoparticles
Ingestion exposure
- Occurs from hand-to-mouth contact
- Control by using gloves when handling
nanoparticle products
- Hand washing before eating, drinking
or smoking is also important

15. Possible Health Effects
Dermal exposure
• Harmful effects arising from skin exposure may either occur locally within
the skin or alternatively the substance may be absorbed through the skin
and disseminated via the bloodstream, possibly causing systemic effects.
• Dermal absorption of nanoparticles has not been well investigated and
suggested that nanoparticles may penetrate into hair follicles where
constituents of the particles could dissolve in the aqueous conditions and
enter the skin.
• It is reasonable to postulate that nanoparticles are more likely to
penetrate, but this has not yet been demonstrated. Several
pharmaceutical companies are believed to be working on dermal
penetration of nanoparticles as a drug delivery route.

16. Control of Nanoparticles
Skin Exposure
• Skin penetration may occur
mainly in the later stages of
the process, recovery or
surface contamination.
• Some evidence shows that
nanoparticles penetrate into
the inner layers of the skin and
possibly beyond, into the
blood circulation.

17. Health Risk Studies
These agencies are conducting studies of potential health risks
of nanomaterials:
- The National Institute of Environmental Health Sciences (including the
National Toxicology Program);
- The National Institute for Occupational Safety and Health (NIOSH);
- The Environmental Protection Agency (EPA);
- The Department of Defense;
- The Department of Energy (DOE);
- The National Science Foundation (NSF)
- INAIL

18. ACUTE TOXICITY
Lipid Peroxidation Assay (MDA)
Cytotoxicity (necrosis) assay (MTT and LDH
Release)

20. Lipid peroxidation (Malonyldialdehyde, MDA)

21. LDH ASSAY

22. Long term toxicity
Glutathione Assay
Apoptosis assay: (Caspase 3 Activation)
Autophagy Assay: Analysis of MAP LC3I to
LC3-II Conversion by Western Blot

23. In Vitro Characterization
Detection of Endotoxin Contamination Detection
of Microbial Contamination
Detection of Mycoplasma Contamination
Cell Binding/Internalization
Analysis of Hemolytic Properties of Nanoparticles Analysis
of Platelet Aggregation
Analysis of Nanoparticle Interaction with Plasma Proteins
Coagulation Assay
Detection of Nitric Oxide Production by Macrophages

24. Concerns raised by in vitro studies on the toxicity of gold
nanoparticles include cyanidation of elemental gold in
neutrophils,36 initiation of eryptosis,37 spermatoxicity,38
nephrotoxicity,39 and irreversible binding to the major grooves
of DNA (although this is specific to 1.4 nm gold nanoparticles).40
In vivo studies have reported gold nanoparticle toxicity detected
as changes in gene expression in the liver and spleen,7 and 41
changes in hematology and blood chemistry indicating liver and
kidney damage and an inflammatory response,42 and
histological maladies including apoptosis and inflammation in
various organs.43, 44 and 45 More recent concerns about
toxicity such as rashes, proteinuria, and immune disorders have
resulted in abandonment of use of gold in the treatment of
patients with rheumatoid arthritis which has motivated the
development of newer anti-immune therapies (etanercept,
abatacept, and rituximab).