66 research outputs found
Multiplexed five-color molecular imaging of cancer cells and tumor tissues with carbon nanotube Raman tags in the near-infrared
Single-walled carbon nanotubes (SWNTs) with five different C13/C12 isotope
compositions and well-separated Raman peaks have been synthesized and
conjugated to five targeting ligands in order to impart molecular specificity.
Multiplexed Raman imaging of live cells has been carried out by highly specific
staining of cells with a five-color mixture of SWNTs. Ex vivo multiplexed Raman
imaging of tumor samples uncovers a surprising up-regulation of epidermal
growth factor receptor (EGFR) on LS174T colon cancer cells from cell culture to
in vivo tumor growth. This is the first time five-color multiplexed molecular
imaging has been performed in the near-infrared (NIR) region under a single
laser excitation. Near zero interfering background of imaging is achieved due
to the sharp Raman peaks unique to nanotubes over the low, smooth
autofluorescence background of biological species.Comment: Published in Nano Researc
Polyvalent Oligonucleotide Gold Nanoparticle Conjugates as Delivery Vehicles for Platinum(IV) Warheads
Amine-functionalized polyvalent oligonucleotide gold nanoparticles (DNA-Au NPs) were derivatized with a cisplatin prodrug, and the resulting DNA-Au NP conjugates were used to internalize multiple platinum centers. A platinum(IV) complex, c,c,t-[Pt(NH[subscript 3])[subscript 2]Cl[subscript 2](OH)(O[subscript 2]CCH[subscript 2]CH[subscript 2]CO[subscript 2]H)], was tethered to the surface of DNA-Au NPs through amide linkages. The platinum-tethered gold nanoparticles were taken into several cancer cells. The drop in intracellular pH facilitated reductive release of cisplatin from the prodrug, which then formed 1,2-d(GpG) intrastrand cross-links in the cell nuclei, as confirmed by an antibody specific for this adduct. The cytotoxicity of the platinum(IV) complex increases significantly in several cancer cell lines when the complex is attached to the surface of the DNA-Au NPs and in some instances exceeds that of cisplatin.National Cancer Institute (U.S.) (Grant CA034992)National Cancer Institute (U.S.) (MIT-Harvard Center for Cancer Nanotechnology Excellence 5U54CA11934)David H. Koch Institute for Integrative Cancer Research at MI
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