Nanotoxicity - The Nanobiotechnology - page 605

chemistry.. This. is. evidenced. by. poly. (diallyldimethyl. ammonium. chloride). (PPDDAC)-
coated.Au.NRs.exhibiting.a.much.greater.ability.to.be.internalized.by.the.cells.compared.
to. PSS-. (Poly-sodium- p -styrenesulfate). and. CTAB. (cetyltrimethylammonium. bromide)-
coated. samples. (Figure. 27.3e;. Qiu. et. al.. 2010,. Wang. et. al.. 2010a).. In. nanobiotechnology,.
various.nanosynthesis.and.nanofabrication.methods.have.been.applied.to.nanomaterials.
with.the.intent.to.obtain.specialized.and.much.needed.characteristics..However,.the.posi-
tive.aim.on.nanomaterial.modiications.may.result.in.unintended.side.effects,.which.raises.
alarms. about. potentially. damaging. health. effects. including. biocompatibility. and. acute.
and.chronic.toxicity.
Surface.charge,.which.can.be.changed.by.surface.modiication,.is.one.of.the.most.essen-
tial. factors. that. directly. relates. to. the. biological. functions. of. nanoparticles.. In. contrast.
to.neutral.and.negatively.charged.nanoparticles,.positively.charged.particles.can.lead.to.
the.most.eficient.cell.membrane.penetration.and.cellular.internalization.because.of.their.
effective.binding.to.the.negatively.charged.groups.on.the.cell.surface..In.regards.to.the.Au.
nanoparticles,. it. was. shown. that. only. positively. charged. particles. could. induce. cellular.
membrane.depolarization.among.all.tested.cell.types..The.extent.of.membrane.depolariza-
tion.was.found.to.be.dependent.on.the.concentration.of.positively.charged.nanoparticles..
In. comparison,. membrane. depolarization. induced. by. negative,. neutral,. or. zwitterionic.
Au.nanoparticles.was.negligible..Therefore,.the.intracellular.uptake.of.positively.charged.
nanoparticles. proved. to. be. signiicantly. higher. than. the. other. conditions. (Arvizo. et. al..
2010)..It.also.forms.the.primary.platform.as.synthetic.carriers.for.drug.and.gene.deliver-
ies.in.nanobiotechnology..Following.the.application,.there.are.requirements.to.investigate.
the.destiny.and.functions.after.intercellular.uptake.of.charged.nanoparticles..Fluorescent.
polystyrene.(PS).particles.are.good.research.objects.to.study.the.intercellular.dynamics.of.
allogenic.materials.in.a.cell.model..We.have.recently.investigated.the.negatively.charged.
carboxylated.polystyrene.(COOH-PS).and.positively.charged.amino-modiied.polystyrene.
(NH 2 -PS).nanoparticles.of.three.different.diameters.(50,.100,.and.500.nm).on.cancer.HeLa.
cells.and.normal.NIH.3T3.cells.during.the.cell.cycles..We.found.that.the.PS.nanoparticles.
keep.a.distance.from.the.spindle.and.the.chromosomes.during.the.entire.process.of.mito-
sis..They.were.never.found.to.be.associated.with.any.components.of.the.mitotic.appara-
tus.and.no.abnormal.cell.division.was.detected.after.their.internalization..No.abnormal.
daughter.cells.were.detected.as.well..The.data.showed.that.the.PS.nanoparticles.cannot.
inluence.mitosis,.which.is.highly.conserved.in.mammal.cells,.in.both.normal.and.cancer.
cells.(Liu.et.al..2011).
At. present,. the. data. available. on. the. toxicity. of. nanomaterials. are. fragmentary,. and.
sometimes.contradictory,.which.is.also.accompanied.by.their.complicated.physicochemi-
cal. characteristics.. Scientists. have. to. face. this. current. dificulty. that. a. safe. borderline. of.
application.dose.cannot.be.set.or.a.predetermined.recommendation.in.the.use.of.nanoma-
terials.can.be.given..There.are.many.factors.that.must.be.considered.during.the.application.
of.these.materials.in.nanobiotechnology.
27.3 Absorption, Translocation, and Distribution of Nanoparticles In Vivo
People. within. nanotechnology-related. research,. production,. and. application. have. the.
potential. to. be. exposed. to. nanomaterials.. Absorption. and. penetration. occurs. mainly.
through. the. skin,. gastrointestinal. (GI). tract,. lung,. nasal. cavity,. eyes,. and. intravenous.