Lighting up cancer: latest discoveries in ruthenium(ii) polypyridyl complexes for anticancer photodynamic therapy

Photodynamic therapy (PDT), which utilises light-sensitive compounds to specifically target cancer cells while preventing harm to neighbouring healthy tissues, presents a potentially viable alternative treatment option. Ruthenium (Ru) polypyridyl complexes have garnered considerable attention as prospective PDT agents owing to their capability to generate stable and selective molecules by structural modification through ligands replacement. Additionally, their intricate geometries and oxidation states contribute to their therapeutic potential. This review provides the evolution and application of Ru(ii) polypyridyl complexes in PDT as a cancer treatment modality. It analyses the efficacy, mechanisms of action, and advancements of these complexes in comparison to conventional methods. We present the design and optimisation of these complexes, emphasising their critical importance in combination therapies to circumvent the shortcomings of existing PDT methods and achieve enhanced therapeutic outcomes. Our review subsequently examines the practical implications of the results, highlighting the need for further in vivo experiments to validate Ru(ii) polypyridyl complexes as viable therapeutic agents for cancer. Future studies aiming to enhance the effectiveness of PDT could significantly benefit from the incorporation of nanotechnology and advanced delivery systems.