The harm and treatment of methyl blue (MB) were described, and the necessity for the removal of MB by magnetic nanomaterials was explained. Magnetic Ni-Mg-Co ferrites were prepared by the rapid combustion approach of an active nitrate solution and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR), energy dispersive spectroscopy, and vibrating sample magnetometer. Magnetic Ni 0.1 Mg 0.7 Co 0.2 Fe 2 O 4 nanoparticles prepared at 400 C with the saturation magnetization of 19.7 emu g À1 and the average diameter of about 15.2 nm were used to adsorb MB from the aqueous medium. The Brunauer-Emmett-Teller (BET) analysis showed that the specific surface area was 143.17 m 2 g À1 and the average pore size was 9.44 nm. The adsorption mechanism of MB onto magnetic Ni 0.1 Mg 0.7 Co 0.2 Fe 2 O 4 nanoparticles was studied, and the results revealed that the adsorption properties conformed the pseudo-second-order kinetics model due to the square deviation values (R 2 > 0.98), and Temkin model could describe the adsorption state of MB onto Ni 0.1 Mg 0.7 Co 0.2 Fe 2 O 4 nanoparticles, which suggested that the adsorption of MB onto Ni 0.1 Mg 0.7 Co 0.2 Fe 2 O 4 nanoparticles was monolayer-multilayer hybrid chemisorption mechanism. When the pH value exceeded 3, the adsorbance reached large value; while, the adsorbance was 97.6% of the initial adsorption value for seven cycles. The electrochemical impedance spectroscopy and cyclic voltammetry curves of MB adsorbed onto the nanoparticles before and after the adsorption were determined.

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Magnetic Fe 3 O 4 nanoparticles were prepared via a simple hydrothermal method and utilized to load paclitaxel. The average particle size of Fe 3 O 4 nanoparticles was found to be 20.2 ± 3.0 nm, and the calculated saturation magnetization reached 129.38 emu/g, verifying superparamagnetism of nanomaterials. The specific surface area and pore volume were 84.756 m 2 /g and 0.265 cm 3 /g, respectively. Subsequently, Fe 3 O 4 @mSiO 2 nanoparticles were successfully fabricated using the Fe 3 O 4 nanoparticles as precursors with an average size of 27.81 nm. The relevant saturation magnetization, zeta potential, and specific surface area of Fe 3 O 4 @mSiO 2 -NH 2 -FA were respectively 76.3 emu/g, −14.1 mV, and 324.410 m 2 /g. The pore volume and average adsorption pore size were 0.369 cm 3 /g and 4.548 nm, respectively. Compared to free paclitaxel, the solubility and stability of nanoparticles loaded with paclitaxel were improved. The drug loading efficiency and drug load of the nanoformulation were 44.26 and 11.38%, respectively. The Fe 3 O 4 @mSiO 2 -NH 2 -FA nanocomposites were easy to construct with excellent active targeting performance, pH sensitivity, and sustained-release effect. The nanoformulation also showed good biocompatibility, where the cell viability remained at 73.8% when the concentration reached 1200 μg/mL. The nanoformulation induced cell death through apoptosis, as confirmed by AO/EB staining and flow cytometry. Western blotting results suggested that the nanoformulation could induce iron death by inhibiting Glutathione Peroxidase 4 (GPX4) activity or decreasing Ferritin Heavy Chain 1 (FTH1) expression. Subsequently, the expression of HIF-1α was upregulated owing to the accumulation of reactive oxygen species (ROS), thus affecting the expression of apoptosis-related proteins regulated by p53, inducing cell apoptosis.

A rapid combustion process was applied to prepare CaFe2O4 nanomaterials using CaBr2·xH2O and Fe(NO3)3·9H2O as raw materials and CaFe2O4 nanomaterials were characterized by SEM, TEM, VSM, XRD, and FTIR techniques. The results showed that the prepared nanomaterials had a sheet-like structure, and for larger adsorption capacity of dyes, CaFe2O4 nanosheets prepared at 700°C for 2 h with average grain size was 93.3 nm, a thickness of 8.4 nm, and the saturation magnetization of 8.15 emu/g were employed as adsorbate for the removal of methyl blue (MB). The adsorption performance of MB onto CaFe2O4 nanosheets was investigated; CaFe2O4 nanosheets displayed favorable adsorption capacity, and the adsorption conformed to the pseudo-second-order model and the Freundlich model, which demonstrated that the adsorption process of MB on CaFe2O4 nanosheets belonged to multilayer chemisorption process. When the pH value reached 3, the adsorption capacity of MB by CaFe2O4 nanosheets kept maximum value of 478.07 mg/g; and after 5 regenerations, the removal efficiency of MB was reduced to 59.06% of the first time. The electrochemical behavior of MB onto the nanosheets was evaluated through CV in conjunction with EIS. The CaFe2O4 nanosheets revealed a promising prospect for the adsorption of dyes.