Biomedical Engineering Reference
In-Depth Information
novel.diagnostics.and.therapeutics..Many.researchers.have.explored.various.strategies.to.
prepare. nanosized. devices. or. particles. for. drug/gene. delivery. and. imaging.. Herein,. we.
introduce.engineering.strategies.to.harvest.nanostructures.for.cellular-level.applications..
The.choice.of.nanotechnology.methods.matches.the.properties.of.the.component.materials.
including.charge,.molecular.weight,.hydrophobicity,.architecture,.functional.domain,.and.
toxicity..Polymer.or.polymer-lipid-based.nanostructures.were.mostly.used.as.drug/gene.
carriers,.in.cell.imaging,.or.as.biosensors.with.metal.or.magnetic.material.involvement.
The. nanofabrication. techniques. are. mainly. classiied. into. top-down. and. bottom-up.
fabrication.techniques..Top-down.strategies.include.techniques.such.as.photolithography,.
x-ray. lithography,. electron. beam. (e-beam). and. focused. ion. beam. (FIB). lithography,. etc..
These. methods. were. originally. used. in. semiconductive. industrial. and. research. ields,.
and. usually. giant. and. expensive. equipment. was. needed.. Bottom-up. approaches. use.
the. self-organization. of. molecules,. lipids,. or. polymers. to. generate. structured. materials.
without. external. intervention,. which. broadly. beneits. inorganic. and. biological. systems..
The.mechanism.of.self-assembly.is.usually.based.on.electrostatic.interaction.between.two.
components. (a. pair. of. oppositely. charged. colloids. or. macromolecules).. These. materials.
include. lipids,. polymers,. and. nuclei,. and. present. nanosized. structures. when. contacting.
with. each. other. to. form. micelles,. spheres,. or. irregular. shapes. in. large. size. distribution.
(Discher.and.Ahmed.2006,.Immordino.et.al..2006)..For.achieving.uniform.shape.structures.
at. the. microscale. and. the. nanoscale,. many. advanced. top-down. particle. fabrication.
techniques. have. been. explored,. including. microluidic-based. approaches,. hard. template.
methods,. particle. stretching. methods,. and. photo-. and. e-beam. lithography. techniques.
(Merkel. et. al.. 2010).. For. example,. DeSimone. and. his. colleagues. developed. a. top-down.
fabrication. technique. termed. particle. replication. in. non-wetting. templates. (PRINT).
technology,.which.enables.independent.control.over.particle.size,.shape,.modulus,.surface.
chemistry,.and.composition.(Wang.et.al..2011)..The.advantage.of.this.technique.is.that.the.
chemical.composition.of.nanoparticles.can.be.tailored.without.changing.the.size,.shape,.and.
dynamics.of.the.particle..Several.materials.like.biocompatible.and.biodegradable.polymers,.
inorganic.materials,.and.biologics.can.be.applied.to.PRINT.particle.fabrication..To.optimize.
the.PRINT.particle.parameters.for.cell.internalization,.polyethylene.glycol-based.particles.
with.rod-like.shapes.and.cylindrical.counterparts.of.similar.volume.(around.0.007.μm
3
).were.
used.to.investigate.the.rate.and.effect.of.Hela.cell.internalization..The.results.showed.that.
the.particle.shape.plays.an.important.role.in.cell.internalization,.and.the.rod-like.shaped.
nanoparticle. presented. the. better. process.. For. multipurpose. applications,. magnetic. or.
luorescent.materials.have.been.added.into.nanoparticles.for.gene.delivery.or.cell.imaging.
studies.. Here,. we. demonstrate. recent. nanoparticle. works. from. the. integrative. biological.
view. for. biomedical. application.. A. magnetic. mesoporous. silica. siRNA-PEI. nanoparticle.
(M-MSN_siRNA@PEI).package.was.prepared.with.the.characteristics.of.being.213.nm.in.
size.and.17.7.±.1.7.mV.in.zeta.potential.value..This.type.of.nanoparticle.was.internalized.by.
A549.cells.in.2.h.into.cytoplasm.at.37°C.and.demonstrated.a.positive.silencing.effect.for.the.
target.gene.(Li.et.al..2011)..Another.example.is.gold.nanoparticles.(AuNPs).incorporation.
into. human. red. blood. cells. (RBC). to. produce. contrast-enhanced. tracers. designed. for.
dynamic.x-ray.imaging.of.blood.lows..This.approach.offers.great.potential.in.obtaining.
valuable.quantitative.information.from.nontransparent.blood.lows.for.clinical.diagnosis.
and. treatment. of. circulatory. disorders.. The. AuNPs. coated. with. hydrophobic. functional.
groups. seem. to. effectively. disassemble. cytoskeletal. and. adopter. proteins,. which. can. be.
considered.an.indicator.of.how.the.incorporation.process.operates.(Ahn.et.al..2011).
Nanoparticles. made. from. biocompatible. materials. exhibit. multiple. functions,. such. as.
vector.or.carrier.roles.for.gene.or.drug.delivery.and.tracer.effects.for.internal.or.external.
