Design, synthesis and biological evaluation of choline based SPECT imaging agent: Ga(III)-DO3A-EA-Choline.
The enhanced choline uptake and phosphorylation in tumor cells has motivated the development of radiolabeled choline derivatives as diagnostic markers for imaging cell membrane proliferation and noninvasive detection of prostate, brain and breast tumors. In the present work, we report a facile strategy for the synthesis of choline functionalized macrocyclic chelating agent (DO3A-EA-choline) and its radiocomplexation with (67)Ga for potential tumor imaging applications. The synthesis of the desired compound featured quaternization of N,N-dimethylaminoethanol with 1,2-dibromoethane followed by subsequent alkylation with trisubstituted cyclen (DO3A). All intermediates and final compounds have been fully characterized by spectroscopic techniques, namely, (1)H, (13)C NMR and mass spectroscopy. The compound has been successively labeled with (67)Ga-citrate in ammonium acetate buffer (pH 6.5) at 80 °C. MTT assays have been performed on the HEK cell line to determine the cytotoxicity of the compound. Cell uptake studies carried out on the U-87 MG cell line exhibited saturable binding of the radioconjugate in picomolar range with a K(d) value of 0.528 pM. The in vivo biodistribution and blood kinetics studies exhibited rapid clearance of the radiolabeled complex and excretion through the renal and hepatobiliary route. The present studies demonstrate the potential applications of (67)Ga-DO3A-EA-choline as a radiopharmaceutical for molecular imaging using ((67/68)Ga) SPECT and PET modalities.
Institute of Nuclear Medicine and Allied Sciences, Brig. S. K. Mazumdar Road, Delhi-110054, India.
Jasleen K
JK
Uppal
Puja P
PP
Hazari
Raunak
Krishna
K
Chuttani
Michele
M
Allard
Narender K
NK
Kaushik
Anil K
AK
Mishra
D000818:Animals; D002460:Cell Line; D002463:Cell Membrane Permeability; D002470:Cell Survival / Q000187:drug effects; D002794:Choline / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D015195:Drug Design; D006801:Humans; D051379:Mice; D015394:Molecular Structure; D009928:Organ Specificity; D011817:Rabbits; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology; D015899:Tomography, Emission-Computed, Single-Photon
D056831:Coordination Complexes; D019275:Radiopharmaceuticals; D002794:Choline