Monodisperse Fe3O4/SiO2 and Fe3O4/SiO2/PPy Core-Shell Composite Nanospheres for IBU Loading and Release

Abstract

The magnetic targeting drug delivery system is an effective way of targeting therapy. In this study, the monodisperse Fe3O4 nanoparticles with a particles size of about 180 nm were first prepared via a solvothermal method. Subsequently, the core-shell structure Fe3O4/SiO2 and Fe3O4/SiO2/polypyrrole (PPy) composite nanospheres were successfully synthesized by coating Fe3O4 nanoparticles with SiO2 shell layer using the Stöber method and PPy shell by solvothermal method in turn. The as-prepared nanoparticles were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA), and Ultraviolet-Visible spectrophotometer (UV-Vis). The results indicated that the as-prepared composite nanospheres displayed a well-defined core-shell structure and monodispersity. The thicknesses of SiO2 shell and PPy shell were ~6 nm and ~19 nm, respectively. Additionally, the as-prepared nanoparticles exhibited high saturation magnetization of 104 emu/g, 77 emu/g, and 24 emu/g, and have great potential applications in drug delivery. The drug loading and drug release of the Fe3O4/SiO2 and Fe3O4/SiO2/PPy composite nanospheres to ibuprofen (IBU) under stirring and ultrasonication were investigated. Their drug loading efficiency and drug release efficiency under ultrasonication were all higher than 33% and 90%, respectively. The drug release analyses showed sustained release of IBU from nanospheres and followed the Korsmeyer-Peppas model.

Preparation and characterization of an electromagnetic composite polypyrrole/polyethylene short filament geotextile

“…There are sharper characteristic peaks at 1602 cm −1 in polypyrrole due to the C=C absorption bands of polypyrrole at these two peaks, and the absorption peak at 3415 cm −1 is due to the N-H stretching vibration of the polypyrrole, which is a broader absorption peak. 37–39…”

“…There are sharper characteristic peaks at 1602 cm À1 in polypyrrole due to the C¼C absorption bands of polypyrrole at these two peaks, and the absorption peak at 3415 cm À1 is due to the N-H stretching vibration of the polypyrrole, which is a broader absorption peak. [37][38][39] Raman spectra of the polypyrrole/polyethylene short filament geotextile composite. The polypyrrole/PE short filament geotextile composite was tested by Raman spectroscopy analysis and the results are shown in Figure 8.…”

Comparison of the Surface Properties of Hydrothermally Synthesised Fe3O4@C Nanocomposites at Variable Reaction Times

“…Meanwhile, the bands at 3396, 2347 and 1635 cm −1 are assigned to OH vibrations at the surface of the as-prepared magnetite NPs. The OH groups were inherited from the ethylene glycol molecules [ 33 , 34 , 35 ] and has higher vibrational intensities in Fe 3 O 4 NPs over Fe 3 O 4 @C. The reduced vibrational intensities of these bands in Fe 3 O 4 @C indicate that, during glucose carbonisation, the carbon composited and effectively shielded the OH groups [ 36 ]. The peaks at 2848 and 2937 cm −1 are attributed to the antisymmetric and symmetric stretching vibration of C–H bonds introduced by ethylenediamine molecules at the solvothermal step for Fe 3 O 4 NPs fabrication [ 37 , 38 ].…”

“…Weak to medium intensity peak at the 1385 cm −1 was ascribed to the antisymmetric C–N stretching vibrations coupled with the out-of-plane H–NH and N–H vibrational modes [ 33 ]. The peak at 870 cm −1 was assigned to the in-plane and out-of-plane vibrational modes for residual C–H bonds deformation [ 34 ]. Several peaks disappeared, shifted to new wavenumbers, or were retained in the resulting nanocomposites.…”

Silica-Coated Fe3O4 Nanoparticles as a Bifunctional Agent for Magnetic Resonance Imaging and ZnII Fluorescent Sensing

“…Dual functional and multifunctional magnetic core shell Fe 3 O 4 @SiO 2 nanocomposites as a special carrier have attracted more and more attention. [1][2][3][4][5][6] The silica shell outside the iron oxide core not only increases the and biocompatibility and stability of nanoparticles in water environment, but also provides convenient sites for modifying ligands in biomedical applications, such as biological separation, [7][8][9] drug targeting, [10][11][12][13][14] cell separation, 8 enzyme immobilization [15][16][17][18] and protein purification. 19 In addition, Fe 3 O 4 @SiO 2 MNPs are more and more studied because they are easy to prepare and friendly to aqueous solution, 20 and can be designed into various shapes and sizes.…”