2,2'-Bipyrimidine-based luminescent Ru(ii)/Ir(iii)-arene monometallic and homo- and hetero-bimetallic complexes for therapy against MDA-MB-468 and caco-2 cells

G2/M-Phase-Inhibitory Mitochondrial-Depolarizing Re(I)/Ru(II)/Ir(III)-2,2'-Bipyrimidine-Based Heterobimetallic Luminescent Complexes: An Assessment of In Vitro Antiproliferative Activity and Bioimaging for Targeted Therapy toward Human TNBC Cells

Triple-negative breast cancer (TNBC) is an extremely vicious subtype of human breast cancer having the worst prognosis along with strong invasive and metastatic competency. Hence, it can easily invade into blood vessels, and presently, no targeted therapeutic approach is available to annihilate this type of cancer. Metal complexes have successfully stepped into the anticancer research and are now being applauded due to their anticancer potency after the discovery of cisplatin. Many of these metal complexes are also well recognized for their activity toward breast cancer. As the TNBC is a very dangerous subtype and has long been a challenging ailment to treat, we have intended to develop a few brand new mixed metallic Ru(II)/Ir(III)/Re(I)-2,2'-bipyrimidine complexes [L'Re2], [L'RuRe], and [L'IrRe] to abate the unbridled proliferation of TNBC cells. The potency of the complexes against TNBC cells has been justified using MDA-MB-468 TNBC cell lines where complex [L'IrRe] has displayed significant potency among all the three complexes with an IC₅₀ value of 24.12 μM. The complex [L'IrRe] has been competent to cause apoptosis of TNBC cells through inhibition of the G2/M phase in the cell cycle in association with a profuse amount of ROS generation and mitochondrial depolarization.

Effect of the Solvent on the Crystallographic and Magnetic Properties of Rhenium(IV) Complexes Based on 2,2′-Bipyrimidine Ligand

Two solvated rhenium(IV) complexes with formula [ReCl4(bpym)]·MeCN (1) and [ReCl4(bpym)]·CH3COOH·H2O (2) (bpym = 2,2′-bipyrimidine) have been prepared and characterized by means of Fourier transform infrared spectroscopy (FT–IR), scanning electron microscopy and energy dispersive X-ray analysis (SEM–EDX), single-crystal X-ray diffraction (XRD) and SQUID magnetometer. 1 and 2 crystallize in the monoclinic system with space groups P21/n and P21/c, respectively. In both compounds, the Re(IV) ion is six-coordinate and bound to four chloride ions and two nitrogen atoms of a 2,2′-bipyrimidine molecule forming a distorted octahedral geometry around the metal ion. In the crystal packing of 1 and 2, intermolecular halogen⋯halogen and π⋯halogen-type interactions are present. Hydrogen bonds take place only in the crystal structure of 2. Both compounds exhibit a similar crystal framework based on halogen bonds. Variable temperature dc magnetic susceptibility measurements performed on microcrystalline samples of 1 and 2 show a similar magnetic behavior for both compounds, with antiferromagnetic exchange between the Re(IV) ions connected mainly through intermolecular Re-Cl⋯Cl-Re interactions.

One pot three component synthesis of DNA targeting phototoxic Ru(II)-p-cymene dipyrido[3,2-a:2',3'-c]phenazine analogues

We have developed a one pot three component synthetic protocol for half-sandwich Ru(II)-p-cymene dipyrido[3,2-a:2',3'-c]phenazine analogues for selective cancer therapy under light irradiation. On average, the cytotoxicity of all the complexes is indeed doubled upon light irradiation and also exhibited significant photo and dark selectivity against cancer cells with respect to normal cells. Out of five Ru(II) complexes (RuL1-RuL5), [(η⁶-p-cymene)Ru^IICl(K²-N,N-11-nitrodipyrido[3,2-a:2',3'-c]phenazine]PF₆ (RuL4) exhibited the best phototoxicity (lowest IC₅₀ under light irradiation). Intracellular ROS generation was studied by the 2',7'-dichlorofluorescein diacetate (DCFH-DA) assay. Moreover, these complexes exhibited a strong serum albumin and DNA binding capacity. These complexes also exhibited good stability in 10% DMSO-buffer and under 1 mM GSH conditions. Overall, the remarkable photocytotoxic efficacy of new Ru(II)-p-cymene dipyrido[3,2-a:2',3'-c]phenazine analogues (RuL1-RuL5) makes them potential photochemotherapeutics as an alternative of current PDT agents.

Ru(ii)arene(N^N bpy/phen)-based RAPTA complexes for in vitro anti-tumour activity in human glioblastoma cancer cell lines and in vivo toxicity studies in a zebrafish model

Herein, we have introduced a series of half-sandwich Ru(ii)arene(N^N bpy/phen)-based RAPTA complexes for brain cancer therapy. Among all the synthesized complexes, [(η⁶-p-cymene)Ru^II(κ²-N,N-4,7dimethyl phenanthroline)(PTA)]·2PF₆ (4c) and [(η⁶-p-cymene)Ru^II(κ²-N,N-4,7diphenyl phenanthroline)(PTA)]·2PF₆ (4d) showed outstanding potency against the T98G, LN229 and U87MG cancer cells. The antiproliferative activity of these complexes was reinforced by neurosphere, DNA intercalation, agarose gel electrophoresis, cell cycle analysis and time-dependent ROS detection assays. The real-time reverse transcription (RT)-polymerase chain reaction (PCR) study showed that complex 4c inhibited the TNF-α-induced NF-κB phosphorylation in glioma cells. Moreover, the in vivo biodistribution of complex 4c in different organs and the morphological patterns of widely used zebrafish embryos due to toxic effects have been evaluated.

A series of half-sandwich Ru(ii)arene(N^N bpy/phen)-based RAPTA complexes have been developed for brain cancer therapy.