Controllable morphology CoFe₂O₄/g-C₃N₄ pH-responsive nanoplatform for enhanced chemo-photodynamic synergistic cancer therapy

In this study, four cobalt ferrite@carbon nitride (CoFe₂O₄@g-C₃N₄) composites were prepared by co-precipitation method to achieve chemo-photodynamic synergistic cancer therapy. The effect of the morphology of g-C₃N₄ on the chemotherapy and photodynamic therapy of CoFe₂O₄@g-C₃N₄ (CFO@g-C₃N₄) was investigated in detail. CFO@PMCN with porous structures and CFO@CNT with a reticulated structure displayed high loading efficiencies of doxorubicin (DOX), exhibiting a pH-responsive release property and facilitating the delivery of DOX into cancer cells for chemotherapy. CFO@CNT possessed a higher photothermal performance for photothermal agents in cancer treatment compared with other CoFe₂O₄@g-C₃N₄ composites. In addition, more reactive oxygen species (ROS) was generated in the assistance of CFO@CNT under the irradiation condition for photodynamic therapy (PDT) treatment. Based on the synergistic effect of chemotherapy and photodynamic therapy, the obtained CFO@CNT-DOX exhibited an excellent therapeutic effect and significant pH-responsive release characteristics confirmed by dimethylthiazol diphenyltetrazolium bromide (MTT) assay and dual staining fluorescence imaging analysis.