Synthesis, characterization and preliminary in vitro cellular uptake studies of 67Ga(III) thiosemicarbazones

Preliminary experiments were conducted using the radiometal 67Ga and a select series of thiosemicarbazones. A series of five monothiosemicarbazone ligands was synthesized via a Schiff-base condensation reaction. Radiolabelling studies were performed using 67GaCl3. The successfully radiolabelled complexes (with labelling efficiencies ranging from 87% to more than 99%) were tested for their radiochemical stability in saline and foetal bovine serum. While all the complexes are stable in saline, only one compound showed some degree of radiochemical stability in serum. In vitro cellular uptake of the radiochemically stable complex was evaluated against rat ovarian cancer (DMBA OC1R) cells, human breast cancer (MCF 7) cells and non-cancerous brain endothelial (bEND5) cells. A clear correlation between cellular uptake of the radiolabelled complex and cell count was observed.