Macrophages‐Based Biohybrid Microrobots for Breast Cancer Photothermal Immunotherapy by Inducing Pyroptosis

Abstract Pyroptosis‐based immunotherapy can escape drug resistance as well as inhibit metastasis. It is urgently required to develop a delivery platform to induce targeted tumor‐specific pyroptosis for cancer immunotherapy. Herein, macrophages‐based biohybrid microrobots (IDN@MC) are constructed with IR‐macrophage and decitabine‐loaded Metal‐organic frameworks (DZNPs). The integration of fluorescence photosensitizers and pH‐sensitive DZNPs endow the microrobots properties such as photothermal conversion, fluorescent navigation, targeted drug delivery, and controlled drug release. In light of the inherent tumor targeting, tumor accumulation of IDN@MC is facilitated. Due to the sustained release of decitabine from packaged DZNPs, the host macrophages are differentiated into M1 phenotypes to exert the tumor phagocytosis at the tumor site, directly transporting the therapeutic agents into cancer cells. With laser control, the rapid and durable caspase 3‐cleaved gasdermin E (GSDME)‐related tumor pyroptosis is achieved with combined photothermal‐chemotherapy, releasing inflammatory factors such as lactate dehydrogenase and interleukin‐18. Subsequently, the robust and adaptive immune response is primed with dendritic cell maturation to initiate T‐cell clone expansion and modulation of the immune suppressive microenvironment, thus enhancing the tumor immunotherapy to inhibit tumor proliferation and metastasis. This macrophages‐based biohybrid microrobot is an efficient strategy for breast cancer treatment to trigger photo‐induced pyroptosis and augment the immune response.