Preparation and evaluation of 99mTc-labeled zidovudine function as an analog of thymidine in the diagnosis of human lung cancer cells

Labeled nucleotide detectors provide a basis for measuring cell division. Zidovudine is a prodrug that is phosphorylated by cellular enzymes at the 5ʹ position and converted to active triphosphate. Zidovudine triphosphate interferes with the reverse transcriptase enzyme and lengthens the viral DNA strand.

Ethyl-2-propynyl acetate and 2-amino-N-propynyl benzamide ligands were obtained by the reaction of ethyl-2-amino-acetate hydrochloride with propargyl bromide and isatuic anhydride with propargylamine, respectively. Then, a click reaction was performed between the acetylene group of the ligands and the azide group of zidovudine, and a 1,2,3-triazole ring was formed in the chelating products. The resulting structures were labeled with [99mTc(CO)3(H2O)3]+ complex. Qualitative control and then radiotherapy stability in normal saline were performed using HPLC. In vitro studies were performed to evaluate the accumulation of radiotherapy using the blocking method.

The chemical structures of chelating compounds were confirmed by proton and carbon magnetic resonance spectroscopy and elemental analysis. Using optimal conditions, the thymidine analogs were labeled with the desired yield. The labeled compounds had good stability in normal saline and showed entry into lung cancer cells.

These studies demonstrated the capability of labeled azidothymidine analogs as a tool for molecular imaging of cancer.