Design, Synthesis, and Structural Insights of a Series of Zn(II)–NSAID Based Coordination Complex Derived Metallogels and Their Plausible Applications in Self Drug Delivery

Structural rationale was exploited in designing a series of Zn(II) coordination complexes derived from benzimidazole (BZ), 2-pyridin-2-yl-1H-benzimidazole (PBZ), sodium salts of various nonsteroidal anti-inflammatory drugs (NSAIDs), and Zn(NO3)2 as potential metallogelators. Single crystal X-ray diffraction (SXRD) studies carried out on nine coordination complexes provided crucial structural insights. As many as five metallogels were successfully prepared and characterized by rheology and optical and electron microscopies. Two selected metallogelators derived from PBZ and the sodium salt of naproxen and meclofenamic acid (PBZNAP and PBZMEC) displayed anticancer activity against melanoma cell line B16-F10 as revealed by MTT and scratch assays. A zone inhibition assay carried out on two bacteria, viz., Escherichia coli and Staphylococcus aureus, revealed that the metallogels PBZNAPg, PBZIBUg, PBZDICg, and PBZMECg were significantly active against the bacteria. The results indicated that a self-drug-delivery system could indeed be developed following the structural rationale adopted herein