Biomedical Engineering Reference
In-Depth Information
FIGURE 4.3
Fluorescent.image.of.nanoparticle.drug.delivery..A.C32.melanoma.cell,.transfected.to.express.green.luorescent.
protein,.is.targeted.by.a.perluorocarbon.nanoparticle.carrying.red.Rhodamine.dye.(a.luorescent.mimic.for.a.
drug)..The.dye.streams.from.the.particle.as.part.of.the.cell's.phospholipid.membrane.and.can.be.seen.over.the.
entire.cell..The.inset.shows.a.magniied.view.of.the.Rhodamine.dye.melting.from.the.nanoparticle.to.the.cancer.
cell..(Reprinted.with.permission.from.Crowder,.K.C.
,
et.al.,.
Ultrasound Med Biol
,.31,.1693-1700,.2005.)
fumagillin.to.smaller.tumors.in.mice..These.tumors,.which.exhibit.a.much.lower.level.of.
angiogenesis,. had. a. measurable,. albeit. diminutive,. effect. of. therapy.. Considering. these.
two.studies,.one.might.appreciate.the.power.of.these.theragnostic.nanoparticles.in.char-
acterizing.the.amount.of.angiogenesis.prior.to.initiating.therapy,.predicting.response,.and.
guiding.choices.
77
.In.the.cases.where.only.minute.amounts.of.angiogenesis.are.present,.an.
aggressive.and.costly.regimen.of.antiangiogenic.therapy.may.not.be.warranted;.another.
course.may.be.more.effective.
While. the. previous. examples. of. targeted. therapy. all. involved. fumagillin. as. the. drug.
agent,. chemotherapeutics. such. as. paclitaxel,
71
. doxorubicin,
71
. and. rapamycin,
78
. and. even.
toxic.peptides.such.as.mellitin
79
.and.thrombolytic.enzymes
80
.have.been.effectively.incor-
porated.into.perluorocarbon.nanoparticles..In.many.cases,.targeted.nanoparticles.offer.a.
new.opportunity.to.candidate.drugs.that.would.otherwise.be.far.too.toxic.to.use.systemi-
cally..Mellitin,.a.toxic.peptide.derived.from.honeybee.venom,.nonspeciically.attacks.lipid.
membranes,.disrupting.virtually.every.cell.it.encounters..Designing.it.into.a.perluorocar-
bon.nanoparticle.(coined.nanobee
81
),.however,.isolates.its.disruptive.effects.to.only.those.
cells.speciically.targeted.
79
