Biomimetic Nanosystem Loading Aggregation‐Induced Emission Luminogens and SO2 Prodrug for Inhibiting Insufficient Photothermal Therapy‐Induced Breast Cancer Recurrence and Metastasis

Abstract Photothermal therapy (PTT) holds considerable clinical promise. However, insufficient PTT‐induced tumor recurrence and metastasis is an urgent practical problem that needs to be solved. Herein, a biomimetic mesoporous organosilicon nano‐system called PSAB is designed to precisely deplete cancer stem cells (CSCs) and prevent tumor recurrence and metastasis after PTT. The PSAB system is made up of Aggregation‐induced emission (AIE)‐active photothermal agent, 2TT‐ o C26B, and SO 2 prodrug, benzothiazole sulfinate (BTS), within mesoporous organosilicon nanoparticles (MON) enclosed by an exterior platelet membrane. PSAB effectively targets CSCs both in vitro and in vivo by P‐selectin/CD44 interaction. The degradation of MON and subsequent release of BTS and AIE molecules are facilitated by intracellular glutathione (GSH). Subsequently, the acidic tumor environment triggers the SO 2 gas therapy from BTS. This process leads to the depletion of GSH and CSCs elimination. After combining PSAB with photothermal therapy, there is no significant tumor recurrence or metastasis. These results indicate that SO 2 gas therapy and AIE‐mediated PTT act synergistically to offer a unique approach for preventing tumor recurrence and metastasis after PTT, thus holding significant promise for clinical applications in cancer PTT.