Toxicology and Risk Assessment - Nanotechnology and the Environment - page 216

table . (Continued)
effects of nanomaterials or nanoparticles on Mammalian species

size or
diameter species Particle a Category exposure or dose endpoint(s) effect(s) Commentary Ref.

Rat Single-walled.carbon.

nanotube.(SWCNT)

Diameters.<.2.nm,.
with.lengths.
ranging.from.0.5.
to.40.µm.and.a.
purity.>.90%.

Oropharyngeal.
aspiration.of.2.mg/
kg-bw..Evaluated.
(bronchoalveolar.
lavage).1.and.21.days.
post.exposure

Lung-lung.
histopathology,.
ibrogenic.
potential,.cell.
proliferation,.and.
growth.factor.
mRNAs..
Exposure.
biomarker

SWCNT.did.not.cause.lung.
inlammation,.but.induced.the.
formation.of.small,.focal.
interstital.ibrotic.lesions.in.
the.alveolar.region.of.rat.
lungs.

Of.greatest.interest.—.unique.
intercellular.carbon.structures.
composed.of.SWCNT-bridged.
lung.macrophages..These.
bridges.offer.an.easily.
identiiable.exposure.
biomarker.

[48]

C57BL/6.Mice SWCNT 1-4.nm 0,.10,.20,.or.40.µg/

mouse;.pharyngeal.
aspiration..Animals.
euthanized.at.1,.3,.7,.
28,.and.60.days.post.
exposure

Oxidative.stress/
cytotoxicity.lung

Acute.inlammation.with.early.
onset,.progressive.ibrosis.and.
granulomas..Dose-dependent.
increase.in.oxidative.stress.
biomarkers..Functional.
respiratory.deiciencies.and.
decreased.bacterial.clearance.
also.observed.

Results.support. in vitro .studies. [24]

Human.ibroblasts SWCNT

MWCNT
Carbon.black
Activated.carbon
Carbon.graphite

2.nm
200.nm
25.nm
50.nm
500.nm

0.8,.1.61,.3.125,.6.25,.
12.5,.25,.50,.and.100.
µg/mL.for.1.to.5.days

Cytotoxicity Cellular.apoptosis/necrosis..

SWCNTs.induced.strongest.
cellular.apoptosis/necrosis..
Reined.SWCNTs.are.more.
toxic.than.unreined.
counterpart.

Results.suggest.that.toxicity.of.
nanomaterials.increases.with.
increase.in.surface.area.

[26]