Nitrile-Containing Terpyridyl Zn(II)-Coordination Polymer-Based Metallogelators Displaying Helical Structures:...

An attempt has been made to develop a self-drug-delivery system against melanoma from a series of metallogelators derived from coordination polymers. Thus, a series of coordination polymers (CP1-CP6) derived from a nitrile-containing terpyridyl ligand (L) and transition metal salts (Cu(I)/Zn(II)) have been synthesized and thoroughly characterized by a number of physicochemical techniques including single crystal X-ray diffraction. Reactions of the ingredients of the coordination polymers guided by their single crystal structures produced four metallogels (CPG2-CPG5) which were characterized by dynamic rheology and TEM. The metallogelator CPG3 turned out to be the best suited for further studies as revealed from MTT assay against melanoma (B16-F10) and macrophage (RAW 264.7) cells. Various experiments (scratch, cell cycle, nuclear condensation, annexin V-FITC/PI, mitochondrial membrane potential, Ho-efflux assays) not only supported the "druglike" action against melanoma B16-F10 cells but also suggested that the mechanism of cancer cell death was via mitochondrial membrane potential depolarization-driven apoptosis. Because melanoma B16-F10 is a model cell line for human skin cancer, the metallogel CPG3 may, therefore, be further developed for such treatment.