Metal Complexes of Platinum, Palladium, and Ruthenium: From Chemical Design to Medical Applications

Metal-based compounds have emerged as promising candidates for anticancer therapy, offering structural diversity and mechanisms of action beyond those of conventional chemotherapeutic agents. This review examines palladium-, platinum-, and rutheni-um-based compounds, focusing on their coordination chemistry, structure–activity rela-tionships, anticancer mechanisms, and therapeutic potential. Platinum-based agents re-main established components of cancer treatment, although their clinical use is limited by toxicity and drug resistance. Palladium complexes have demonstrated diverse biological effects, including DNA interactions, oxidative stress, mitochondrial dysfunction, and apoptosis, while ruthenium compounds exhibit distinct pharmacological properties in-fluenced by ligand structure, biological transformations, and interactions with cellular targets. Recent developments, including Pt(IV) prodrugs and multifunctional plati-num-based nanomedicines, highlight strategies to improve drug delivery and therapeutic performance. Despite encouraging preclinical findings, challenges involving selectivity, stability, mechanistic understanding, and clinical translation remain. Further research integrating rational molecular design, comprehensive biological evaluation, and clinically relevant models is essential to advance the development of safer and more effective met-al-based anticancer therapies.