Synthesis of multifunctional magnetic mesoporous Fe3O4@MSN@PPy-HA nanospheres for pH-responsive drug release and photothermal in tumor therapy

In this paper, superparamagnetic ferric oxide (Fe3O4) nanospheres were prepared by hydrothermal synthesis and Fe3O4@MSN@PPy-HA composite microspheres were prepared by coating the Fe3O4 with mesoporous silica nanospheres (MSN) layer, photothermal conversion materials polypyrrole (PPy) and tumor-targeting ligand hyaluronic acid (HA). The chemotherapy drug doxorubicin (DOX) was added to the above materials to prepare the tumor-targeting Fe3O4@MSN@PPy-HA@DOX microspheres. The composite nanospheres have excellent drug loading ability, controlled drug release ability, photothermal conversion performance, and good biological safety, which can be used in the treatment of tumors. Under the irradiation of the NIR laser, the photothermal conversion efficiency of Fe3O4@MSN@PPy-HA nanospheres can reach 24.61 %, realizing the thermal ablation of tumor sites. The bivalent iron ion (Fe2+) contained in the nanospheres can have a Fenton reaction with the hydrogen peroxide (H2O2) in tumor cells to form cytotoxic hydroxyl radical (·OH), thus achieving the tumor chemodynamic therapy (CDT). This study confirmed that the microspheres have a good tumor inhibition effect and provided a new idea for the design of multifunctional composite nanomaterials.