Biomedical Engineering Reference
In-Depth Information
Ocular
exposure
Dermal
exposure
Inhalation
uptake
Intravenous
injection
Oral
uptake
Nasal cavity
GI tract
Lymphatic
system
Respiratory
tract
Brain
Circulation system
(blood)
Organs
Figure 27.4
(See companion CD for color igure.)
.Predominant.translocation.and.distribution.routes.of.nanoparticles.in.
vivo.. The. ive. gray. shaded. boxes. indicate. the. primary. routes. of. nanoparticle. entry.. The. arrows. down. from.
these.uptake.sites.show.potential.translocation.pathways..(Reproduced.with.modiication.by.permission.from.
BioMed. Central,. Yokel,. R.A.. and. Macphail,. R.C.,. Engineered. nanomaterials:. Exposures,. hazards,. and. risk.
prevention,.
J. Occup. Med. Toxicol
.,.6,.7,.2011.)
injection..Figure.27.4.summarizes.these.predominant.routes.and.potential.translocation.
pathways.of.nanoparticles.in.vivo.
Intravenous.injection.has.been.widely.used.in.biomedical.ields.with.the.development.of.
nanobiotechnology..The.nature.and.intensity.of.biological.effects.of.nanoparticles.depend.
on.their.physicochemical.characters.such.as.size,.chemical.composition,.surface.structure,.
solubility,. shape,. and. how. the. individual. nanoparticles. accumulate. together.. Once. the.
nanoparticles. enter. the. body,. they. can. travel. freely. in. the. blood. throughout. the. body.
and.may.cross.the.blood-brain.barrier,.which.is.one.of.the.promising.target.applications.
of. nanotechnology. in. clinical. neuroscience.. Non-coating. nanoparticles. (usually. with.
hydrophobic. surfaces). are. recognized. as. strange. bodies. and. captured. by. macrophages,.
which. causes. accumulated. particles. in. the. macrophages. located. in. organs. such. as. liver,.
spleen,.lungs,.and.bone.marrow..It.has.been.described.that.nanoparticles.with.hydrophilic.
surfaces. have. a. longer. circulation. time. in. the. bloodstream.. Until. now,. surface. coatings.
and.modiications.were.simply.hot.topics.in.biotechnology.as.they.both.directly.link.to.the.
toxicity.and.blood.circulation.retention.ability.of.nanoparticles.in.the.body..In.addition,.the.
circulating.blood.contains.more.than.2000.proteins,.which.have.been.shown.to.opsonize.
entered.nanomaterials..The.opsonization.is.an.important.metabolism.or.biotransformation.
process.to.nanomaterials.within.the.organism..It.is.thought.that.the.nanoparticles'.surface.
coating.is.extremely.important.because.this.will.greatly.inluence.their.function.when.they.
contact.cells.(Walczyk.et.al..2010,.Monopoli.et.al..2011)..Opsonization.is.believed.to.occur.
within.seconds.and.usually.is.inluenced.by.the.composition.and.shape.of.nanomaterials.
(Cherukuri.et.al..2006,.Monopoli.et.al..2011)..Recently,.we.have.compared.the.interaction.
processes. between. SWCNTs. and. human. blood. proteins,. ibrinogen,. immunoglobulin,.
albumin,. transferrin,. and. ferritin,. using. both. experimental. and. theoretical. approaches..
It. has. been. found. that. there. is. competitive. binding. of. different. blood. proteins. onto. the.