Biomedical Engineering Reference
In-Depth Information
injected,.after.48.h,.nanoparticles.were.observed.to.migrate.toward.the.interior.of.the.stem.
parenchyma,. evidently. assisted. by. cellular. structures,. but. now. directly. associated. with.
the.vascular.system..A.second.method.involving.spraying.led.to.no.nanoparticles.in.the.
plant.other.that.in.the.outer.epidermal.layer.
Treated.plants.were.examined.using.light.and.electron.microscopy..Evidence.suggested.
localization. of. nanoparticles. after. injection,. as. well. as. migration. from. the. application.
point..Placement.of.a.magnet.on.the.stem.of.the.plant.indicated.long-range.movement.of.
the.particles.and.concentration.near.the.magnet.
26.4.3 Carbon Nanotubes as Delivery Systems
In.2009,.Liu.and.co-workers.used.carbon.nanotubes.to.directly.deliver.chemicals.to.tobacco.
BY-2. cells.
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. The. investigators. showed. the. capability. of. single-walled. carbon. nanotubes.
(SWNTs).to.penetrate.the.cell.wall.and.cell.membrane..Confocal.luorescent.microscopy.
revealed. cellular. uptake. of. SWNTs. conjugated. to. the. dye. FITC,. as. well. as. SWNT-dye-
DNA.conjugates..Confocal.microscopy.showed.SWNT-luorescein.conjugates.internalized.
in.BY-2.cells.(see.Figure 26.4),.and.demonstrated.that.SWNTs.“hold.great.promise.as.nano-
transporters.for.walled.plant.cells.”
The. effects. of. multiwalled. carbon. nanotubes. (MWNTs). were. studied. in. tomato. by.
Khodakovskaya. et. al.
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. MWNTs. were. produced. using. Fe/Co/CaCO
3
. catalysts. and. puri-
ied.to.>98%.purity.as.assessed.by.TEM.and.Raman.spectroscopy..Seeds.grown.in.media.
containing.MWNTs.exhibited.faster.seed.germination.and.faster.seedling.growth,.leading.
to.greater.biomass..MWNTs.were.found.to.penetrate.tomato.seeds.and.affect.their.germi-
nation..The.germination.was.found.to.be.dramatically.higher.for.seeds.that.germinated.on.
medium.containing.MWNTs.(10−40.μg/ml).than.for.the.control..Analytical.methods.indi-
cated.that.the.MWNTs.are.able.to.penetrate.the.thick.seed.coat.and.support.water.uptake.
HOOC
COOH
HOOC
FIGURE 26.4
Top:. Confocal. microscope. image. of. whole. tobacco. plant. cells. BY-2. incubated. with. SWNT-FITC. compound..
Bottom:.Structure.representation.of.SWNT-FITC.compound.used.in.Liu.et.al.
33
.(Reprinted.from.Liu,.Q.,.et.al.,.
Nano Letters
,.9(3),.1007,.2009..With.permission.of.the.American.Chemical.Society.)
