Synthesis and preliminary biological evaluation of a technetium-99m labeled thymidine analog

The synthesis and labeling of 99mTc-N3-{N′-[2-sulfanyl-ethylamino)acetyl]-2-aminoethyl-sulfanyl-1-hexanamide}thymidine (99mTc-NHT) were studied. In the presence of sodium glucoheptonate (GH) and ethylene diamine tetraacetic acid (EDTA), 99mTc-NHT was obtained by using bisaminoethanethiol (N2S2) as a bifunctional coupling agent. The radiochemical purity of the 99mTc-NHT was over 95%. Biodistribution of 99mTc-NHT was performed in hepatoma HepA tumor-bearing mice. At 2 h p.i., the ratios of tumor-to-muscle, tumor-to-bone and tumor-to-blood were 4.41 ± 0.32, 2.45 ± 0.24 and 1.51 ± 0.18, respectively.