Biomedical Engineering Reference
In-Depth Information
8.6. In.Vitro.Evaluation.of.Trastuzumab-Conjugated.Nanoparticles................................ 172
8.6.1. In.Vitro.Cellular.Uptake........................................................................................ 172
8.6.2. In.Vitro.Cytotoxicity............................................................................................... 173
8.7. Summary............................................................................................................................. 175
References..................................................................................................................................... 175
8.1 Nanotechnology
Nanotechnology. is. a. multidisciplinary. ield. and. can. be. deined. as. a. science. and. engi-
neering.discipline.that.involves.the.design,.synthesis,.characterization,.and.application.
of.materials.and.devices.whose.smallest.functional.organization.in.at.least.one.dimen-
sion.is.on.the.nanometer.scale.
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.Nanotechnology.opens.the.door.to.a.new.generation.of.
techniques. and. devices. for. cancer. diagnosis,. treatment,. and. prevention.. For. example,.
intracellular. imaging. can. be. achieved. with. the. aid. of. nanotechnology,. in. which. mul-
ticolor. luorescence. imaging. is. realized. by. attaching. imaging. agents. such. as. semicon-
ductor. quantum. dots. (QDs). to. selected. molecules,. or. coating. the. QDs. with. a. layer. of.
amphiphilic.molecules..Moreover,.nanoparticles.with.a.drug.encapsulated.in.a.polymer.
matrix.can.realize.a.controlled.and.sustained.manner.for.drug.delivery..Controlling.the.
localization. of. nanoparticles. to. the. diseased. cells. by. modiication. of. the. nanoparticle.
surface.with.targeting.moieties.is.now.gaining.great.interest.in.the.ield.of.nanomedi-
cine..Not.only.can.anticancer.drugs.be.incorporated.in.the.nanoparticles.to.kill.the.can-
cer.cells,.but.diagnostic.agents.as.well,.which.can.be.utilized.to.image.the.presence.of.
cancer.cells..The.latter.will.be.powerful.in.detecting.the.development.of.cancer.at.very.
early.stages..This,.in.turn,.promises.better.and.more.effective.treatment.for.cancer.dis-
eases.than.ever.before.
8.2 Nanoparticles
Recently,.biodegradable.nanoparticles.have.attracted.great.interest.due.to.their.advantages.
over. conventional. therapeutic. strategies.. Types. of. such. nanoparticles. include. polymeric.
micelles,. liposomes,. and. polymer-based. nanoparticles.. Nanoparticles. of. biodegradable.
polymers. can. be. used. as. therapeutics. containing. small-molecule. drugs,. peptides,. pro-
teins,. and. nucleic. acids.. Compared. to. conventional. therapeutic. strategies,. nanoparticles.
can.improve.the.solubility.of.poorly.soluble.drugs.and.increase.the.drug.half-life,.as.well.
as.the.speciicity.to.the.target.sites,.e.g.,.tumors..Most.nanoparticles.preferentially.accumu-
late.within.tumors.via.the.enhanced.permeability.and.retention.(EPR).effect.
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.Thus,.poly-
meric. nanoparticles. allow. for. enhancing. the. intracellular. drug. concentration. in. cancer.
cells.while.avoiding.toxicity.in.normal.cells,.resulting.in.potent.therapeutic.effects.
There.are.a.variety.of.nanoparticle.systems.being.developed.for.cancer.diagnosis.and.
therapeutics.. The. material. properties. of. each. nanoparticle. system. have. been. developed.
to.enhance.delivery.to.the.tumor..For.example,.hydrophilic.surfaces.can.be.used.to.pro-
vide.the.nanoparticles.with.stealth.properties.for.longer.circulation.times,.and.positively.
charged. surfaces. can. enhance. endocytosis.. Nanoparticles. can. be. tailor-made. to. achieve.
both. controlled. drug. release. and. disease-speciic. localization. by. altering. the. polymer.
characteristics.and.surface.chemistry.
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