Recent progress in development of new sonosensitizers for sonodynamic cancer therapy

Developing an effective treatment for cancer is still a challenge. Despite great success with traditional cancer therapies, there are numerous disadvantages for conventional treatments such as systemic toxicity, low selectivity, drug resistance and potential long-term side effects. Recently, photodynamic therapy (PDT) has been widely applied in clinical settings. However, this approach suffers from the major shortcoming derived from the limited penetrability of visible light. Sonodynamic therapy (SDT) utilizing ultrasound combined with a sonosensitizer represents a novel noninvasive approach for cancer therapy, which is deemed to overcome the disadvantage of PDT. In this review, we extensively summarize the recent progress in the discovery of new sonosensitizers for SDT and discuss the future directions for the development of novel sonosensitizers.