99mTc-N4amG: Synthesis biodistribution and imaging in breast tumor-bearing rodents

99mTc-N4-guanine (99mTc-N4amG) was synthesized and evaluated in this study. Cellular uptake and cellular fraction studies were performed to evaluate the cell penetrating ability. Biodistribution and planar imaging were conducted in breast tumor-bearing rats. Up to 17%ID uptake was observed in cellular uptake study with 40% of 99mTc-N4amG was accumulated in the nucleus. Biodistribution and scintigraphic imaging studies showed increased tumor/muscle count density ratios as a function of time. Our results demonstrate the feasibility of using 99mTc-N4amG in tumor specific imaging.

► Synthesis and radiolabeling of a novel guanine based radiotracer, 99mTc-N4amG.
► Up to 17%ID uptake was observed in cellular uptake study after 4 h incubation.
► In cellular fraction study, 40% of 99mTc-N4amG was accumulated in the nucleus.
► Imaging studies of 99mTc-N4amG showed increased tumor/muscle density ratios.