Recent trends in the design and delivery strategies of ruthenium complexes for breast cancer therapy

As the most frequent and deadly type of cancer in women, breast cancer has a high propensity to spread to the brain, bones, lymph nodes, and lungs. The discovery of cisplatin marked the beginning of the development of anticancer metal-based medications, although the drug's severe side effects have limited its usage in clinical settings. The remarkable antimetastatic and anticancer activity of different ruthenium complexes such as NAMI-A, KP1019, KP1339, etc. reported in the 1980s has bolstered the discovery of ruthenium complexes with various types of ligands for anticancer applications. The review meticulously elucidates the cytotoxic and antimetastatic potential of reported ruthenium complexes against breast cancer cells. Notably, arene-based and cyclometalated ruthenium complexes emerge as standout candidates, showcasing remarkable potency with notably low IC50 values. These findings underscore the promising therapeutic avenues offered by ruthenium-based compounds, particularly in addressing the challenges posed by conventional treatments in refractory or aggressive breast cancer subtypes. Moreover, the review comprehensively integrates a spectrum of ruthenium complexes, spanning traditional metal complexes to nano-based formulations and light-activated variants, underscoring the versatility and adaptability of ruthenium chemistry in breast cancer therapy. This review aims to summarise all types of ruthenium complexes for treating ER+, PR+, and triple-negative breast cancer.