Substituent-Modulated Excited Triplet States and Activities of Ruthenium Complexes for Dual Photodynamic/Sonodynamic Therapy to Cisplatin-Resistant Non-Small Cell Lung Cancer.

Six polypyridyl Ru(II) complexes were designed for single-molecule photodynamic and sonodynamic therapy (PDT/SDT) synergistic multimodal anticancer toward cisplatin-resistant NSCLC. They demonstrated lowest 3ES with distinct intraligand transition nature, which is beneficial for singlet oxygen generation. Remarkable quantum yields of both singlet oxygen and superoxide anion under either 808 nm laser irradiation or ultrasonic treatment and could induce apoptosis and ferroptosis of A549R cells. Cytotoxicity experiments clearly demonstrated a synergistic effect between PDT and SDT. The relationship between the structures of these complexes and their cellular biological mechanisms has been explored in detail. Using a single-molecule sensitizer to achieve synergistic PDT/SDT may provide valuable insights for the treatment of drug-resistant tumors that located deeply and in hypoxic microenvironment.