Piezoelectric Materials as Sonodynamic Sensitizers to Safely Ablate Tumors: A Case Study Using Black Phosphorous.
Piezoelectric materials are demonstrated as a new source of sonodynamic sensitizers and BP nanosheet suggested as an excellent sensitizer for tumor sonodynamic therapy, thereby suppressing tumor growth and metastasis without causing off-target toxicity in tumor-bearing mouse models.
Abstract
Sonodynamic therapy eliminates cancer cells with reactive oxygen species (ROS) triggered by ultrasound whose energy is spatiotemporally controllable, safe to human tissues and organs, and deeply penetrating through tissues. Its application, however, is hindered by the scarcity of sonodynamic sensitizers. We herein demonstrate piezoelectric materials as a new source of sonodynamic sensitizers, using few-layer black phosphorous (BP) nanosheet as a model. BP nanosheet exhibited ultrasound-excited cytotoxicity to cancer cells via ROS generation, thereby suppressing tumor growth and metastasis without causing off-target toxicity in tumor-bearing mouse models. The ultrasonic wave introduces mechanical strain to BP nanosheet, leading to piezoelectric polarization which shifts the conduction band of BP more negative than O2/•O2- while its valance band more positive than H2O/•OH, thereby accelerating the ROS production. This work identifies a new mechanism for discovering sonodynamic sensitizers and suggests BP nanosheet as an excellent sensitizer for tumor sonodynamic therapy.