Iridium in Cancer Therapy: A New Frontier in Metal-Based Medicine

Iridium therapy is changing how cancer is treated in the future. Because of their remarkable photophysics, redox sensitivity, and structural adaptability, Ir (III) complexes offer a powerful and multipurpose solution for precision oncology. These substances can be engineered to target particular Compounds organelles, photoinduced activation, and real-time imaging on a single molecular platform, which allows for simultaneous diagnosis and treatment, unlike conventional chemotherapeutics. This review highlights the recent surge in iridium complex synthesis and biomedical applications, with a focus on developments within the past five years. We address their many structural classes, including cyclometalated compounds, mononuclear Ir (III) species, and formulations based on nanoparticles, emphasizing their subcellular accumulation patterns, intracellular trafficking, and cellular uptake methods. Because iridium complexes are better at generating reactive oxygen species (ROS), causing mitochondrial damage, and fragmenting DNA, they can kill cancer cells selectively without harming healthy tissue. Novel strategies such as administration that responds to the tumor microenvironment, induction of immunogenic cell death, and combination with photothermal or radiation are propelling iridium medicines to the forefront of multimodal cancer treatment. Iridium complexes, which are distinguished by their improved pharmacokinetics and biodegradability due to clever nanocarrier engineering, have significantly lower systemic toxicity than platinum equivalents. Iridium-based platforms are powerful anticancer tools with strong translational potential that bridge biology and chemistry, imaging and therapy. This review is meant to serve as a last resort for medicinal chemists, scientists working in nanomedicine, and oncologists who want to maximize iridium's anti-cancer potential.