Synthesis and biodistribution of 99mTc-PyDA as a potential marker for tumor hypoxia imaging

Abstract

The 99mTc-pyrimidine-4,5-diamine (99mTc-PyDA) complex was prepared. The yield under the optimum conditions (5 mg of PyDA, pH 8, 25 μg of SnCl2·2H2O) was 96 ± 3%. The complex is stable in vitro for 24 h. The complex was tested on mice as potential marker for tumor hypoxia imaging. The complex showed high tumor hypoxia uptake with the target/nontarget (T/NT) ratio as high as ∼3.