A highly potent ruthenium(II)-sonosensitizer and sonocatalyst for in vivo sonotherapy

Abstract As a basic structure of most polypyridinal metal complexes, Ru(bpy) 3 2+ , has the advantages of simple structure, facile synthesis and high yield, which has great potential for scientific research and application. However, sonodynamic therapy (SDT) performance of Ru(bpy) 3 2+ has not been investigated so far. SDT can overcome the tissue-penetration and phototoxicity problems compared to photodynamic therapy. Here, we report that Ru(bpy) 3 2+ is a highly potent sonosensitizer and sonocatalyst for sonotherapy in vitro and in vivo. Ru(bpy) 3 2+ can produce singlet oxygen ( 1 O 2 ) and sono-oxidize endogenous 1,4-dihydronicotinamide adenine dinucleotide (NADH) under ultrasound (US) stimulation in cancer cells. Furthermore, Ru(bpy) 3 2+ enables effective destruction of mice tumors, and the therapeutic effect can reach deep tissues over 10 cm under US irradiation. This work paves a way for polypyridinal metal complexes to be applied to the noninvasive precise sonotherapy of cancer.