Nitrile-Containing Terpyridyl Zn(II)-Coordination Polymer-Based Metallogelators Displaying Helical Structures: Synthesis, Structures, and “Druglike” Action against B16-F10 Melanoma Cells

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.