Urchin-like piezoelectric ZnSnO3/Cu3P p-n heterojunction for enhanced cancer sonodynamic therapy

Sonodynamic therapy (SDT) exhibits noninvasive and accuracy in cancer treatment, and has aroused widespread attention. However, the low quantum yield of inorganic sonosensitizers under ultrasound (US) stimulation leads to unsatisfactory efficacy. In this work, an urchin-like piezoelectric ZnSnO3/Cu3P p-n heterojunction was constructed as an efficient sonosensitizer for enhanced SDT. The p-n heterojunction formation narrows the band bandgap and increases the piezoelectric property, which contribute to the promotion of carrier separation and suppression of carrier recombination, resulting in enhanced SDT. Moreover, under tumor microenvironment (TME) with over produced H2O2 and glutathione (GSH), Cu3P NNs induce chemodynamic therapy (CDT) by initiating a Fenton-like reaction and depleting GSH, leading to increased cellular oxidative damage. With the combination effect, the ZnSnO3/Cu3P heterojunction demonstrates a 70% tumor growth inhibition rate in 4T1 tumor mice model. This piezoelectric heterojunction achieves the combined treatment of SDT and CDT, and opens new possibilities for the application of SDT in tumor therapy