Co(III) complex with (E)-2-(2-(pyridine-2-ylmethylene)hydrazinyl)-4-(4-tolyl)-1,3-thiazole: structure and activity against 2-D and 3-D cancer cell models

Co(III) complex with a 2-hydrazonylthiazole ligand was synthesized and characterized by single-crystal X-ray diffraction. In the inner sphere of the complex, two monoionic ligands are coordinated tridentately forming octahedral geometry around Co(III). Activity of the complex was investigated on MCF-7 breast cancer cell line, with cisplatin (CDDP) as a reference compound. Results showed that after 24-h incubation, Co(III) complex revealed stronger cytotoxic activity compared to CDDP. Treatment of MCF-7 3-D cell model with the complex at 10 μM concentration achieved complete suppression of spheroid growth in almost the same extent as at 100 μM. In combination treatments on MCF-7 spheroids, the complex acted synergistically with CDDP, while additive interaction type was achieved when the complex was applied together with paclitaxel.