Versatile delivery systems for non-platinum metal-based anticancer therapeutic agents

Platinum-based anticancer drugs currently available in the market are associated with severe side effects. Therefore, extensive research has been performed to design and synthesize non-platinum metal coordination compounds, while their delivery using nanocarriers has attracted particular interest, providing encouraging results. In this review, coordination compounds based on ruthenium, copper, gold, iridium, palladium, zinc, etc. have received reasonable attention as anticancer agents. Moreover, we summarize the advances reported in the last decade in the design of various nanocarrier types, such as carbon-, amphiphilic copolymer-, polysaccharide-, and protein- or peptide-based nanocarriers, as well as inorganic nanoparticles and metal–organic frameworks, for the delivery of ruthenium-, copper-, gold-, iridium-, palladium- and zinc-based compounds. The delivery of other non-platinum metal-based compounds, the main challenges and future prospects in this field are also discussed. We expect that the future direction of nanocarrier-based delivery systems for non-platinum metal anticancer compounds will lead to a new generation in anticancer medicine.