Biomedical Engineering Reference
In-Depth Information
17.1 IntroductionandBackground
Nanotechnology.involves.the.study,.control,.and.manipulation.of.materials.at.the.nano-
scale,.typically.having.dimensions.on.the.order.of.0.1.to.100.nm,.exhibiting.novel.and.sig-
niicantly.enhanced.physical,.chemical,.and.biological.properties,.functions,.phenomena,.
and.processes.due.to.their.nanoscale.size.
The.large.interest.in.nanostructures.results.from.their.numerous.potential.applications.
in. various. areas,. such. as. materials,. biomedical. sciences,. electronics,. optics,. magnetism,.
environment,.biotechnology,.energy.storage,.and.electricity.
Nanoparticles,. even. from. the. same. material,. can. be. synthesized. utilizing. a. variety. of.
methods..Different.methods.are.used.in.order.to.optimize.speciic.properties.of.materi-
als..These.properties.include,.but.are.not.limited.to,.size.(diameter,.length,.volume),.size.
distribution,.symmetry,.surface.properties,.surface.coating,.purity,.ease.of.manipulation,.
yield,.and.suitability.of.scaling.up.
Magnetic.nanoparticles.such.as.magnetite.and.maghemite.have.been.in.use.in.areas.of.
environment,.bioscience,.and.medicine..Their.unique.magnetic.properties.allow.them.to.
move.in.high.magnetic.ield.gradients,.making.them.useful.in.areas.such.as.drug.target-
ing.and.drug.separation..Potential.applications.for.biosensing.techniques.may.also.employ.
magnetic.particles.by.selectively.binding.the.particles.to.species.of.interest.and.mobiliz-
ing.them.under.a.magnetic.ield..In.almost.all.applications.of.nanoparticles,.the.prepara-
tion.method.of.nanomaterials.represents.one.of.the.most.important.challenges.that.will.
determine.the.particle.size.and.shape,.the.size.distribution,.the.surface.chemistry.of.the.
particles,.and.consequently.their.magnetic.properties..Due.to.their.magnetic.characters,.
magnetite.(Fe
3
O
4
).nanoparticles.can.be.attracted.by.a.magnetic.ield.and.are.easily.sepa-
rable.in.a.solution..Magnetite.is.also.one.of.the.most.commonly.used.magnetic.materials.
because.it.has.a.strong.magnetic.property.and.low.toxicity.
To.date,.many.approaches.have.been.developed.for.the.preparation.of.magnetic.nanopar-
ticles;.they.usually.lead.to.complicated.processes.or.require.relatively.high.temperature.
Several.applications.of.nanomaterials.to.biology,.environment,.and.medicine.have.been.
suggested.and.are.being.studied,.such.as.luorescent.biological.labels,.drug.and.gene.ther-
apy,. biodetection. of. pathogens,. detection. of. proteins,. probing. of. DNA. structure,. tissue.
engineering,.tumor.destruction.via.healing,.separation,.and.puriication.of.biological.mol-
ecules.and.cells,.and.other.applications.
One.application.of.nanoparticles.will.be.the.detection.of.a.small.number.of.bacteria.in.
different.environments,.such.as.blood,.urine,.stool,.water,.and.food..The.current.method.
for.detection.of.microbial.pathogens,.such.as.bacteria.in.water,.food,.and.clinical.samples,.
is.based.on.conventional.microbiological.methods,.which.require.at.least.3-10.days,.and.
on.molecular.biology.methods,.such.as.polymerase.chain.reaction.(PCR),.which.requires.
24-48.h.and.detects.speciic.genes.for.speciic.microorganisms,.but.remains.limited.because.
of.the.potential.presence.of.PCR.inhibitors,.lack.of.information.on.the.viability.of.cells,.and.
low.sensitivity.for.quantiication.of.cells.
Thousands.of.types.of.bacteria.are.naturally.present.in.our.environment..Some.bacteria.
cause.disease.(pathogens).in.humans;.when.certain.pathogens.enter.the.food.and.water.
supply,.they.can.cause.foodborne.illness.or.disease..Foodborne.disease.is.caused.by.con-
suming. contaminated. foods,. water,. or. beverages. The. analysis. of. pathogenic. bacteria. is.
very.important.and.vital.for.food.and.water.safety,.clinical.diagnosis.and.therapies,.pota-
ble.water,.and.prevention.strategies.to.combat.bioterrorism.agents..Many.tests.currently.in.
