Fluorochrome-functionalized nanoparticles for imaging DNA in biological systems.
Attaching DNA binding fluorochromes to nanoparticles (NPs) provides a way of obtaining NPs that bind to DNA through fluorochrome mediated interactions. To obtain a nanoparticle (NP) that bound to the DNA in biological systems, we attached the DNA binding fluorochrome, TO-PRO 1 (TO), to the surface of the Feraheme (FH) NP, to obtain a fluorochrome-functionalized NP denoted TO-FH. When reacted with DNA in vitro, TO-FH formed microaggregates that were characterized by fluorescence, light scattering, and T2 changes. The formation of DNA/TO-FH microaggregates was also characterized by AFM, with microaggregates exhibiting a median size of 200 nm, and consisting of DNA and multiple TO-FH NPs whose individual diameters were only 25-35 nm. TO-FH failed to bind normal cells in culture, but treatment with chemotherapeutic agents or detergents yielded necrotic cells that bound TO-FH and vital fluorochromes similarly. The uptake of TO-FH by HT-29 xenografts (treated with 5-FU and oxaliplatin) was evident by surface fluorescence and MRI. Attaching multiple DNA binding fluorochromes to magnetic nanoparticles provides a way of generating DNA binding NPs that can be used to detect DNA detection by microaggregate formation in vitro, for imaging the DNA of necrotic cells in culture, and for imaging the DNA of a tumor treated with a chemotherapeutic agent. Fluorochrome functionalized NPs are a multimodal (magnetic and fluorescent), highly multivalent (n ≈ 10 fluorochromes/NP) nanomaterials useful for imaging the DNA of biological systems.
Center for Translational Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129, United States.
Hoonsung
H
Cho
David
D
Alcantara
Hushan
H
Yuan
Rahul A
RA
Sheth
Howard H
HH
Chen
Peng
P
Huang
Sean B
SB
Andersson
David E
DE
Sosnovik
Umar
U
Mahmood
Lee
L
Josephson
D000818:Animals; D001665:Binding Sites; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000378:metabolism; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004273:DNA, Neoplasm / Q000737:chemistry / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism*; D019073:HT29 Cells; D006801:Humans; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D051379:Mice; D008819:Mice, Nude; D018625:Microscopy, Atomic Force; D036103:Nanotechnology; D009930:Organic Chemicals / Q000378:metabolism; D010316:Particle Size; D013050:Spectrometry, Fluorescence; D023041:Xenograft Model Antitumor Assays
D004273:DNA, Neoplasm; D005456:Fluorescent Dyes; D058185:Magnetite Nanoparticles; D009930:Organic Chemicals; C405903:TO-PRO-1; D004247:DNA