Macrocyclic chelators with paramagnetic cations are internalized into mammalian cells via a HIV-tat derived membrane translocation peptide.
A major obstacle to using paramagnetic MR contrast agents for in vivo cell tracking or molecular sensing is their generally low cellular uptake. In this study, we show that a paramagnetically labeled DOTA chelator derivatized with a 13-mer HIV-tat peptide is efficiently internalized into mammalian cells. Intracellular concentrations were attained that were readily detectable by MR imaging using both gadolinium and dysprosium chelates. Using this paradigm, it should be feasible to internalize a variety of chemically different agents into mammalian cells.
Bhorade
R
R
Center for Molecular Imaging Research, Massachusetts General Hospital, Harvard Medical School, 149 13th St., #5406, Charlestown, Massachusetts 02129, USA.
Weissleder
R
R
Nakakoshi
T
T
Moore
A
A
Tung
C H
CH
D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002614:Chelating Agents / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D004419:Dysprosium; D005682:Gadolinium; D015696:Gene Products, tat / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism*; D006367:HeLa Cells; D006573:Heterocyclic Compounds, 1-Ring / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007205:Indium Radioisotopes; D008214:Lymphocytes / Q000378:metabolism / Q000648:ultrastructure; D008279:Magnetic Resonance Imaging; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D054322:tat Gene Products, Human Immunodeficiency Virus
D002614:Chelating Agents; D015696:Gene Products, tat; D006573:Heterocyclic Compounds, 1-Ring; D007205:Indium Radioisotopes; D010446:Peptide Fragments; C411322:Tat-DOTA; D054322:tat Gene Products, Human Immunodeficiency Virus; D004419:Dysprosium; D005682:Gadolinium