Biomedical Engineering Reference
In-Depth Information
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Figure 25.12
(See companion CD for color insert.)
.Nanodiamonds.internalized.into.macrophage.cells..(a-e).Confocal.images.
of.FITC-conjugated.nanodiamonds.incubated.with.RAW.264.7.murine.macrophages..(f).TEM.image.showing.
intracellular.presence.of.ND-DOX.complexes.in.macrophage.cells..Scale.bar.represents.20.μm..(Reprinted.by.
permission.from.Huang,.H.,.Pierstorff,.E.,.Osawa,.E.,.and.Ho,.D.,.Active.nanodiamond.hydrogels.for.chemo-
therapeutic.delivery,.
Nano. Lett
.,.7,.3305-3314..Copyright.2007.American.Chemical.Society.)
Recent.work.by.Liu.et.al..shows.that.ND.covalently.linked.with.Paclitaxel.can.signiicantly.
reduce.the.cell.viability.of.A549.human.lung.carcinoma.cells.(Liu.et.al..2010)..Additionally,.
the.ND-Paclitaxel.complex.induces.apoptosis.and.mitotic.arrest.in.A549.cells..Moreover,.
ND-Paclitaxel.inhibits.tumorigenesis.and.lung.cancer.cell.formation.in.Xenograft.severe.
combined. immunodeiciency. mice.. As. a. whole,. the. adsorbed. chemotherapeutic. drug.
still. retains. its. anticancer. activity,. which. results. in. mitotic. blockage. and. apoptosis. and.
inhibits.tumorigenesis.in.human.lung.carcinoma.cells..In.a.separate.study,.Li.et.al..have.
also. investigated. the. application. of. ND. as. an. anticancer. drug. delivery. vehicle. (Li. et. al..
2010).. The. authors. demonstrate. that. the. adsorption. of. 10-hydroxycamptothecin. (HCPT).
onto.ND.surface.is.facilitated.by.physical.attraction.in.diluted.NaOH.solution..Sustained.
release.of.HCPT.from.ND.is.observed.in.low.pH.media..Further.experiments.have.shown.
that.the.chemotherapeutic.effect.of.the.HCPT-ND.complexes.is.much.higher.than.that.of.
the.standalone.HCPT,.suggesting.that.NDs.are.a.promising.multifunctional.drug.delivery.
platform.for.cancer.therapy.
In. cancer. treatment,. chemotherapy. resistance. is. the. major. obstruction.. This. often.
contributes.to.the.recurrence.of.tumors.and.cross-resistance.against.other.chemotherapeutic.
drugs..As.a.result,.it.leads.to.treatment.failure.in.more.than.90%.of.cancer.patients..Thus,.
it.is.important.to.ind.methods.to.overcome.the.drug.resistance.or.to.improve.the.eficacy.
