Mesoporous polydopamine carrying sorafenib and SPIO nanoparticles for MRI-guided ferroptosis cancer therapy.

Iron-based nanomaterials as the main ferroptosis-inducing platforms are more promising because iron itself is a key component in the Fenton reaction to produce ROS. However, the Fe dose needs to be very high in order to induce ferroptosis-based cancer treatment using the SPIO NPs. Therefore, it is still of great challenge to enhance the efficacy of ferroptosis-based cancer therapy by associating the iron-based nanomaterials with other components and therapeutic modalities. In this study, sorafenib (SRF) and ultrasmall SPIO nanoparticles were loaded into the mesopores and onto the surface of MPDA NPs to form SRF@MPDA-SPIO nanoparticles. SPIO loading endowed the system with iron-supply for ferroptosis and made the system MRI-visible. Meanwhile, SRF was able to induce ferroptosis in cancer cells with lower Fe dose. Furthermore, the heat generated by MPDA NPs upon laser irradiation offered a moderate PTT to boost the ferroptosis effect. The SRF@MPDA-SPIO exhibited biocompatibility highly desirable for in vivo application and superior anticancer therapy via the combination of ferroptosis and photothermal therapy.