Biomembrane-coated multifunctional “core-shell” nanoparticles for magnetic hyperthermia induced immunotherapy

Multifunctional “core–shell” nanoparticles were presented via decorating MnO 2 shell on the Fe 3 O 4 core and further coated with 4T1 cancer cell membrane (FMC). The FMC showed switchable multi-modal imaging ability in tumor microenvironment with promoted cancer cells uptake and efficient magnetic hyperthermia/immunotherapy. • Simple nano-system FMC with multifunctional effects of multi-modal imaging and combined tumor therapy. • Real-time nanoparticle distribution monitoring via TME responsive T1/T2 MRI and photoacoustic imaging. • Effective combined magnetic hyperthermia and immunotherapy in vitro and in vivo. Breast cancer is still one of the main threats to women’s health and the development of versatile nanotheranostic agents is of importance. Herein, multifunctional “core–shell” nanoparticles were described by decorating the MnO 2 shell on the Fe 3 O 4 core and further coated with 4T1 cancer cell membrane (FMC). The FMC showed multi-modal imaging ability with switchable magnetic resonance imaging (MRI) from T2 to T1/T2 and photoacoustic imaging (PAI) in the tumor microenvironment due to the dissolution of the MnO 2 shell. Moreover, the cancer cell membrane coating could effectively promote the cancer cell uptake through homotypic targeting. FMC nanoparticles accumulated in the tumor areas were heated under an external alternating magnetic field, driving a magnetic hyperthermia-induced anti-tumor immune response. Our in vitro and in vivo studies showed that self-targeting FMC efficiently localized in 4T1 cancer cells and realized efficient magnetic hyperthermia/immunotherapy with the imaging assistance of T1/T2 MRI and PAI.