Scheme 1.

Schematic illustration of anti-tumor immunotherapy induced by the sonodynamic-immunomodulatory nanostimulator LPM. (A) Synthesis of LPM. (B) LPM are intravenously injected and accumulated in tumors. Upon ultrasound irradiation, plenty of reactive oxygen species produced and evoked pyroptosis of tumor cells, which can release tumor-associated antigen and inflammatory factors to stimulate DCs maturation. The presence of a dense extracellular matrix (ECM) in the tumor is a physical barrier that hinders the subsequent immune response. Released LY364947 induced ECM degradation, resulting in enhanced cytotoxic T lymphocytes infiltration and anti-tumor immunotherapeutic efficiency.