Comprehensive study of hexarhenium cluster complex Na4 [{Re6 Te8 }(CN)6 ] – in terms of a new promising luminescent and X-ray contrast agent

Abstract Octahedral rhenium cluster complexes may have considerable potential as therapeutic and diagnostic drugs due to their luminescent and X-ray contrast properties, as well as their ability to generate singlet oxygen upon photoirradiation. However, their potential biological effects and toxicity in vitro and in vivo are rather far from being understood. Thus, the aim of our research was to study cytotoxicity, intracellular localization and cellular uptake/elimination kinetics in vitro , biodistribution and acute intravenous toxicity in vivo of a complex Na4 [{Re6 Te8 }(CN)6 ] as the promising compound for biomedical application. The results have demonstrated that the complex penetrates through cell membranes with the maximum accumulation in cells in 24 h of incubation and have low toxic effects in vitro and in vivo. The median lethal dose (LD50 ) of intravenously administrated Na4 [{Re6 Te8 }(CN)6 ] is equal to 1082 ± 83 mg/kg. These findings will be useful for future development of cluster-based agents for different biomedical applications.