Biomedical Engineering Reference
In-Depth Information
FIGURE 26.2
(See.color.insert.).The.x-ray.structure.of.plant.photosystem.I.(PSI).at.4.4.A°.from.the.protein.data.bank.(code.
1qzv)..The.protein.backbone.is.in.red,.and.the.chlorophyll.pigments.are.shown.in.blue..The.four.light-harvesting.
proteins.(Lhca1-4).are.at.the.top,.the.region.where.light.is.absorbed.
intact. plant. cell. can. be. triggered.. The. balance. of. this. chapter. discusses. work. on. intact.
plants,.seeds,.whole.plant.cells,.and.protoplasts.
26.3 PlantsasTestSystemsforNanomaterialEnvironmentalToxicology
Many.studies.have.appeared.on.the.environmental.toxicity.of.nanomaterials,.particularly.
in. the. last. decade,. as. engineered. nanoparticles. entered. the. market.. Exotic. new. materials.
like.fullerenes.and.carbon.nanotubes,.as.well.as.other.unique.nanomaterials,.such.as.quan-
tum.dots.(typically.prepared.from.cadmium.selenide.(CdSe)),.captured.the.public.interest..
Nano-versions. of. well-known. inorganic. materials. like. non-nano-titanium. dioxide. (TiO
2
).
and.other.nano-metals.eventually.emerged.as.the.largest.production.materials.of.concern.in.
the.environment..Several.reviews.on.general.aspects.of.environmental.nanotoxicology.are.
available.
11-13
While.mechanisms.allowing.nanoparticles.to.pass.through.cell.walls.and.membranes.
are.as.yet.poorly.understood,.once.inside.cells,.nanoparticles.can.directly.affect.alterations.
in.membranes.and.other.cell.structures.
14
.The.surface.properties.of.engineered.nanopar-
ticles. are. of. essential. importance. for. their. aggregation. behavior,. and. resultant. aqueous.
mobility. and. transport.. While. ecotoxicological. literature. on. engineered. nanoparticles.
shows.toxic.effects.on.ish.and.invertebrates,.as.of.a.2008.review.by.Handy.et.al.,.little.data.
on.terrestrial.plant.species.were.available.
15
.While.the.last.decade.saw.great.advances.in.
nanotechnology. and. a. corresponding. increase. in. the. use. of. nanomaterials. in. products,.
another.2008.review.by.Klaine.et.al..also.criticized.the.lack.of.knowledge.base.for.behavior,.
disposition,.and.toxicity.of.manufactured.nanomaterials.in.plants.
16
