A thermo/pH/magnetic-responsive nanogel based on sodium alginate by modifying magnetic graphene oxide: Preparation, characterization, and drug delivery

A novel thermo/pH/magnetic-triple-responsive nanogel was synthesized by grafting N-isopropylacrylamide and acrylic acid onto sodium alginate to modify magnetic graphene oxide as a drug delivery system. The synthesized nanogel was characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), vibrating sample magnetometer (VSM), atomic force micrographs (AFM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The obtained nanogel displayed excellent reversible transmittance changes in response to pH, temperature, and magnetic field. The performance of the nanogels to load doxorubicin (DOX) drug and to sustain doxorubicin release was tested upon exposure to pH, temperature, and magnetic field variations. The mechanism of drug release was proposed in this paper by different kinetic models. In addition, the effects of nanogels and DOX-loaded nanogels on MCF-7 cells were examined and results were compared with free DOX drug. The in vitro results demonstrated that this triple-responsive nanogel can be an appropriate candidate for applications in cancer therapy.