Advancement of metal compounds as therapeutic and diagnostic metallodrugs: Current frontiers and future perspectives

Abstract Coordination compounds on account of distinctive features of metal ions that include variable oxidation states, diverse range of geometries and coordination numbers, physiologically accessible redox states, and their tendency to coordinate with diverse organic ligands offer a versatile platform for the rational design of novel therapeutic and diagnostic metallodrugs. The prevalence of numerous diseased states which is attributed to either excess or deficiency of a metal ion in the living system validate the therapeutic potential of a metal ion and the related compounds. Although many empirical evidences pertaining to the therapeutic use of metals and their salt compounds have been reported since antiquity, nevertheless the fortuitous discovery of cisplatin served as a benchmark for the development of metallodrugs against several diseased states. Consequently, a vast library of metal compounds have been rationally designed and explored for diverse therapetutic applications viz., anticancer, antimicrobial, antiviral, antidiabetic, diagnosis, imaging, anti-neurodegenerative diseases etc. Notably, many of which have been approved as drugs for clinical use (both therapy and diagnosis) while some are at different stages of clinical trials. Given the wider scope of metallodrugs in the area of medicinal field, this review features a comprehensive overview of the advancements made in metallodrug regimens for the diagnosis and therapies. Various archetypal examples of potential metallodrugs which are currently in clinical use, at different stages of clinical trials or at preclinical development have been highlighted.