Apoptosis in vitro in PC-12 cells induced by an organometallic Ir(III) complex through a ROS-mediated mitochondrial pathway

Aqua-friendly organometallic Ir-Pt complexes: pH-responsive AIPE-guided imaging of bacterial cells

In this work, the aggregation-induced photoluminescence emission (AIPE) of three water-soluble heterobimetallic Ir-Pt complexes was reported with insight into their photophysical and electrochemical properties and imaging of bacterial cells. An alkyne appended Schiff's base L, bridges bis-cyclometalated iridium(III) and platinum(II) terpyridine centre. The Schiff's base (N-N fragment) serves as the ancillary ligand to the iridium(III) centre, while the alkynyl end is coordinated to platinum(II). The pH and ionic strength influence the aggregation kinetics of the alkynylplatinum(II) fragment, leading to metal-metal and π-π interactions with the emergence of a triplet metal-metal-to-ligand charge transfer (³MMLCT) emission. The excellent reversibility and photostability of aggregation-induced emission (AIE) of these aqua-friendly complexes were tested for their ability to sense and selectively image E. coli cells at various pH values.

Sparfloxacin - Cu(II) - aromatic heterocyclic complexes: synthesis, characterization and in vitro anticancer evaluation

Two new copper(II) complexes of sparfloxacin (sf), [Cu(Hsf)(HPB)(H₂O)](ClO₄)₂ (1) and [Cu(Hsf)(PBT)(H₂O)](ClO₄)₂ (2) (where HPB = 2-(2'-pyridyl)benzimidazole and PBT = 2-(4'-pyridyl) benzothiazole), have been synthesized and characterized by physicochemical and spectroscopic techniques. The oil-water partition coefficient (log P) values of complexes 1 and 2 were 1.47 and 1.71, respectively. By studying the interaction between the complexes and DNA, it was found that the complexes could bind to DNA through an intercalation mode. Moreover, both complexes were evaluated for antitumor activity, revealing that the complexes displayed good inhibitory activity toward the tested cancer cell lines (human lung carcinoma A549 cells, human hepatocellular carcinoma Bel-7402 cells and human esophageal carcinoma Eca-109 cells), but showed relatively low toxicity against normal human hepatic LO2 cells. In particular, the antitumor mechanism of the complexes on Eca-109 cells was investigated by morphological analysis, apoptosis analysis and determination of cell cycle arrest, mitochondrial membrane potential, reactive oxygen species (ROS) levels, and release of cytochrome c and Ca²⁺. The results demonstrated that the complexes could induce loss of intracellular mitochondrial functions and increase of ROS levels, which led to an increase of Ca²⁺ levels and the release of cytochrome c into the cytoplasm. In addition, the cell cycle was arrested in the G2/M phase, and western blot analysis showed that the caspase family was activated. These results fully proved that the complexes could induce apoptosis through DNA damage and loss of mitochondrial functions, accompanied by the regulation of endogenous proteins.

Syntheses, structures and anti-tumor activity of four organotin(iv) dicarboxylates based on (1,3,4-thiadiazole-2,5-diyldithio)diacetic acid

Four novel organotin complexes, derived from flexible (1,3,4-thiadiazole-2,5-diyldithio)diacetic acid (H₂tzda), have been synthesized and characterized by elemental analysis, FT-IR, NMR and X-ray crystallography.