Structural Rationale towards Designing Coordination Polymer Based Metallogels Displaying Anti‐Cancer and Anti‐Bacterial Properties

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.

A self-healable metallohydrogel for drug encapsulations and drug release

A self-healable metallohydrogel (MOG) of Mn(ii) has been prepared using a low molecular weight gelator, Na₂HL {H₃L = l-(3,5-di-tert-butyl-2-hydroxy-benzyl)amino aspartic acid}. The MOG has been characterized by MALDI TOF mass spectrometry, rheological studies, IR spectroscopy, and microscopic techniques. Non-steroidal anti-inflammatory drug (NSAID), indomethacin (IND) and anti-cancer drug gemcitabine (GEM) were encapsulated into the metallohydrogel. The GEM-loaded metallogel (MOG_GEM) shows better delivery and more adverse cytotoxicity than the drug against breast cancer cell lines MDA-MB-468 and 4T1. The anti-cancer property was evaluated with in vitro MTT cytotoxic assay, live-dead assay and cell migration assay. In vitro cytotoxicity assay against RAW 264.7 cell line with the treatment of MOG_IND shows the improved anti-inflammatory response in the case of MOG_IND compared to the drug alone.