1. [99mTc(CO)3]+ and [99mTcO2]+ radiolabeled cyclic melanotropin peptides for melanoma SPECT imaging.
- Author
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Zhang X, Teixeira V, Porcal W, Cabral P, Gambini JP, Fernandez M, Gallazzi F, and Quinn TP
- Subjects
- Amines chemistry, Animals, Binding, Competitive, Cell Line, Tumor, Chelating Agents chemistry, Female, Inhibitory Concentration 50, Kinetics, Melanoma, Experimental, Mice, Mice, Inbred C57BL, Multimodal Imaging, Neoplasm Transplantation, Radiopharmaceuticals, Time Factors, Tissue Distribution, Tomography, X-Ray Computed methods, Melanocyte-Stimulating Hormones, Melanoma diagnostic imaging, Peptides, Cyclic, Technetium, Technetium Compounds, Tomography, Emission-Computed, Single-Photon
- Abstract
The melanoma targeting peptides (Ala-triazol)Ac-Re(Arg(11))CCMSH and N4-CO-Re(Arg(11))CCMSH were radiolabeled with [(99m)Tc(CO)3](+) and [(99m)TcO2](+), respectively, and examined for in vitro cell binding, in vivo biodistribution and imaging properties. The (Ala-triazol)Ac-Re(Arg(11))CCMSH and N4-CO-Re(Arg(11))CCMSH were synthesized as protected peptides on resin followed by rhenium cyclization with [(C6H5)3P]2ReOCl3 in DMF. The peptides were labeled with (99m)Tc and examined for radiochemical stability and melanoma cell binding. In vivo biodistribution and SPECT/CT imaging studies were performed in B16/F1 melanoma tumor bearing C57 mice. (99m)Tc(CO)3-(Ala-Triazol)Ac- Re(Arg(11))CCMSH and (99m)TcO2-N4-CO-Re(Arg(11))CCMSH were stable and internalized in B16/F1 melanoma cells upon binding. In vivo biodistribution studies revealed that tumor uptake of (99m)Tc(CO)3-(Ala-Triazol)Ac-Re(Arg(11))CCMSH was 6.08±1.06% ID/g and 7.05±1.48% ID/g at 2 h and 4 h post injection, respectively. Tumor uptake of (99m)TcO2-N4-CORe(Arg(11))CCMSH was 7.54±1.82% ID/g and 2.28±0.22% ID/g at 1 h and 2 h post injection, respectively. SPECT/CT imaging studies showed that tumor selective uptake of the radiolabeled peptides, which was confirmed by competitive blocking studies.
- Published
- 2014
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