Fe₃O₄ Drug Loading Nanoparticles with MRI Enhancement and pH-Sensitive Drug Release Dual Capability

Monodispersed magnetic Fe₃O₄ nanoparticles(MNPs) capped with polyacrylic acid (MNPs-PAA) were synthesized.On this basis,anticancer drug doxorubicin was loaded onto the PAA chain of magnetic nanoparticles (MNPs-DOX) surface by a pH-sensitive hydrazone bond.The morphology,structure,Magnetic Resonance Imaging (MRI) enhancement and drug release properties of MNPs-DOX were characterized by Transmission Electron Microscope (TEM),X-Ray Diffractometer (XRD),Fourier Transform Infrared spectrometer (FT-IR),Thermal Gravimetric (TG) analyzer,UV-Visible spectrophotometer (UV-Vis) and in vitro MRI.MNPs-DOX exhibited great MRI T₂-weighted enhancement capability.The drug-loading capacity of MNPs-DOX was 15% (mass fraction).In vitro experiment demonstrated that the release of DOX was pH-sensitive,and was accelerated at acid environment (pH=5.0) compared with neutral environment (pH=7.4).