Biomedical Engineering Reference
In-Depth Information
PMN
FBGC
EC
(a)
(d)
LC
(b)
(c)
(e)
(f)
Figure 27.2
(See companion CD for color igure.) .Length.determine.the.phagocytosis.of.asbestos.and.CNTs.by.peritoneal.
macrophages..(a,.b).Histological.sections.show.incorporation.of.long-iber.amosite.(a,.arrow).leading.to.“frus-
trated.phagocytosis,”.but.short-iber.amosite.(b,.see.inset).is.successfully.phagocytosed..(c).Representative.
image. of. foreign. body. giant. cells. after. injection. of. long-iber. amosite. containing. short. fragments. of. iber.
(see.inset)..(d).Like.long-iber.amosite,.long.CNTs.(>15.μm).also.lead.to.frustrated.phagocytosis.(EC,.eryth-
rocytes)..(e).In.contrast,.short.CNTs.(<5.μm).can.be.readily.phagocytosed.(see.inset)..(f).Foreign.body.giant.
cells.(FBGC).are.also.present.after.injection.of.long.CNTs.(see.inset.for.internalized.ibers).(PMN,.polymor-
phonuclear. leukocyte;. LC,. lymphocyte).. All. images. are. shown. at. ×1000. magniication. with. a. 5.mm. scale.
bar.. (Reproduced. by. permission. from. Nature. Publishing. Group,. Nat. Nanotechnol .,. Poland,. C.. A.,. Dufin,.
R.,.Kinloch,.I.,.Maynard,.A.,.Wallace,.W..A.,.Seaton,.A.,.Stone,.V.,.Brown,.S.,.Macnee,.W.,.and.Donaldson,.K.,.
Carbon.nanotubes.introduced.into.the.abdominal.cavity.of.mice.show.asbestos-like.pathogenicity.in.a.pilot.
study,.3,.423-428,.2008.)
mass.basis:.SWCNTs.>.MWCNT.(with.diameters.ranging.from.10.to.20.nm).>.quartz.>C 60 .
(Jia. et. al.. 2005).. It. has. been. shown. that. exposing. the. mesothelial. lining. of. the. body.
cavity. of. mice. to. long. CNTs. (longer. than. 15.μm). will. result. in. asbestos-like,. length-
dependent,.pathogenic.behavior.including.inlammation.and.granulomas..In.attempting.
to.phagocytose.or.engulf.a.iber.longer.than.the.length.they.can.completely.enclose,.the.
macrophages.may.resort.to.“frustrated.phagocytosis”.and.giant.cell.formation.caused.by.
macrophage.fusion.in.inlammatory.conditions.(Figure.27.2)..These.pathogenic.outcomes.
have. the. possibility. to. further. develop. mesothelioma,. which. is. normally. observed. in.
asbestos. exposure. (Poland. et. al.. 2008).. These. results. suggest. that. the. cytotoxicity. of.
carbon.nanomaterials.in.vitro.is.highly.dependent.on.their.nanostructure..In.our.lab,.we.
found.the.crystal.structure.of.TiO 2 .had.a.subtle.different.inluence.on.neurotoxicity.after.
30.days.exposure.by.nasal.instillation.on.mice..The.anatase.TiO 2 .particles.had.a.much.
greater.risk.potential.for.producing.adverse.effects.than.the.rutile.ones.on.the.central.
nervous.system.(Wang.et.al..2008b)..The.shape.of.the.nanoparticles.is.another.important.
factor.that.directly.affects.cellular.uptake..We.studied.the.inluence.of.the.geometrical.
aspect.of.Au.nanorods.on.their.cellular.uptake,.and.found.that.the.cellular.uptake.of.Au.
nanorods. was. highly. shape-dependent. (Qiu. et. al.. 2010,. Zhao. et. al.. 2011).. This. showed.
that.much.fewer.longer.nanorods.were.internalized.as.compared.with.shorter.nanorods,.
although.the.two.kinds.of.nanoparticles.had.similar.surface.charges.(Figure.27.3)..The.
spherical. nanoparticles. of. similar. sizes. entered. cells. more. easily. than. rod-shaped. Au.
nanoparticles,.which.can.be.attributed.to.the.longer.membrane.wrapping.time.required.
for.the.rod-shaped.particles.
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