Supramolecular Delivery Systems for NonPlatinum Metal-Based Anticancer Drugs

Stimulated by the enormous success of the inorganic complex cisplatin in tumor treatment, interest in metal complexes has recently grown. Within cells, metal complexes can participate in reactions that are not possible with conventional organic substances, and most of them have promising efficacy as anticancer drugs. However, to be effective in vivo metal complexes need adequate delivery systems able to increase their water solubility, the in vivo bioavailability, and the safe delivery to target organs. The present review reports on the state of the art of these new, nonplatinum, anticancer metallodrugs delivered by nanosized vehicles. The development of complexes of ruthenium, gold, cobalt, copper, gallium, and others that show promising antitumor efficacy is reported, and we emphasize the different approaches in the individuation of the most appropriate delivery system for each of them.