Recent Trends in the Design of Ruthenium Homometallic Polynuclear Complexes with Bioactive Ligands for Cancer Treatment

Significant efforts have been devoted to discovering novel metal-based complexes with better cytotoxicity and specificity to tumor cells. Within the range of complexes studied for cytotoxic activity, Ru complexes have gained significant attention as one of the most promising classes of compounds offering advantages such as good scaffolds for the construction of new bioactive molecules with a variety of ligands. Ruthenium-based compounds demonstrate efficient penetration into cancer cells and show affinity for DNA binding with antitumor mechanisms, other than those of cisplatin. They were identified as perfect chemotherapeutics for cancer treatment due to their good tolerance by normal cells, negligible toxic effects and stronger activity towards Pt-drug-resistant tumor cell lines. Ru-based complexes may interact with multiple targets and show selective accumulation in cancer cells, which enhances their therapeutic potential. In recent years, the design of polynuclear complexes has aroused considerable interest in drug discovery research. The strategy to incorporate two or more metal centers into one precise molecular structure may result in better cytotoxic activity compared to the mononuclear precursors. That is why ruthenium-based multinuclear anticancer organometallic and complex compounds have attracted lots of attention. The objective of the current review is to highlight the key results obtained in research on ruthenium complexes, presenting the up-to-date advances of multinuclear homometallic ruthenium complexes as promising anticancer candidates. The reported outcomes shed new light on the fundamental biological interactions and antineoplastic modes of action of ruthenium-based complexes and organometallic compounds as well as significant information for the prediction of novel anticancer drugs.