Octahedral iodide Mo₆ cluster complex bearing thiosulfate ligands: A dual chemotherapeutic and radiodynamic agent for advanced cancer therapy

Cancer treatment faces significant challenges due to tumor heterogeneity, drug resistance, and the limited efficacy of single-agent therapies, driving the search for novel therapeutic approaches. The water-soluble molybdenum cluster complex Na5Cs3[{Mo6I8}(S2O3)6]·3H2O, developed in this study, represents a unique compound that combines a strong chemotherapeutic effect, achieved through the controlled release of sulfur-containing gas-signaling molecules (H2S and SO2) during hydrolysis, with a radiodynamic effect, enabled by the ability of the cluster to generate singlet oxygen (1O2) under X-rays. The results of in vitro experiments confirmed significant cytostatic effects on cancer cells, while in vivo studies using Nu/J mice xenografted with HeLa tumors showed substantial tumor growth inhibition when the cluster was administered subcutaneously in combination with X-ray irradiation. Overall, the dual functionality of the cluster, along with the slow release and prolonged retention of the complex in tumor tissues, makes it a highly promising candidate for advanced cancer treatment strategies, particularly when integrated with conventional radiotherapy.