A key challenge in immunotherapy for glioblastomas, the most common form of primary adult brain cancer, involves the paucity of immune-stimulatory cells in its "cold" immune-microenvironment.Herein, mechanical acoustic ablation focused by perfluorocarbon (PFC) liquid filled silica microshells is applied to induce immunogenicity via in situ ultrasonic lysis. The inert PFC filled ultra-thin walled silica microshells promote mechanical ablation while aiding in ultrasound guidance. In the presence of PD-1 blockade, tumor injury sites exhibit an increase in tumor infiltrating lymphocytes and