Tumor Microenvironment Triggered in Situ Synthesis of an Excellent Sonosensitizer in Tumor for Sonodynamic Therapy

Ultrasound-triggered sonodynamic therapy has shown great promising for the treatment of tumors, however, only few clinical reports describe the use of sonodynamic therapy, which results from that the traditional sonosensitizers tend to suffer from very poor efficiency combined with low retention in cancer cell and low cancer-selectivity. Here, we constructed a Ti 2 C(OH) X nanosheet, which is a poor sonosensitizer but has long blood circulation. However, tumor microenvironment could turn Ti 2 C(OH) X nanosheet into a novel and excellent sonosensitizer with nanofiber structure in tumor, which exhibits very excellent ability in generating ROS under ultrasound. Moreover, the nanofiber structure of sonosensitizer make it very difficult to get out of cancer cell, highly enhancing the retention of sonosensitizer in tumor, thereby enabling it to effectively and selectively kill cancer cells. The strategy of tumor microenvironment-triggered in situ synthesis of sonosensitizer provide a promising mean to simultaneously increasing efficiency, sonosensitizer retention, and cancer selectivity.