Beta-cyclodextrins conjugated magnetic Fe3O4 colloidal nanoclusters for the loading and release of hydrophobic molecule

Herein, we report a facile method to prepare beta-cyclodextrin (β-CD)-conjugated magnetic Fe 3 O 4 colloidal nanocrystal clusters (Fe 3 O 4 @GLY-CD) using (3-glycidyloxypropyl) trimethoxysilane (GLY) as the intermediate linker. The resulting Fe 3 O 4 @GLY-CD was characterized by several methods including Fourier transform infrared (FT-IR) spectroscopy, field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM). In addition, the loading and release properties of the synthesized Fe 3 O 4 @GLY-CD for the hydrophobic molecule 8-anilino-1-naphthalenesulfonic acid ammonium salt (ANS) were also investigated. The results show that the Fe 3 O 4 @GLY-CD has a spherical structure with an average diameter of 186   nm and high saturated magnetism of 51.2   emu/g. The grafting of β-CD onto Fe 3 O 4 colloidal nanocrystal clusters can markedly increase the loading capacity of ANS because of β-CD/ANS inclusion complex formation. The in vitro delivery profile shows that the release of ANS from the Fe 3 O 4 @GLY-CD nanosystem exhibits an initial burst followed by a slow and steady release. Moreover, Fe 3 O 4 @GLY-CD also demonstrates a temperature-dependent release behavior for ANS owing to the effect of temperature on the association constants of β-CD/ANS inclusion complexes. The developed magnetic hybrid nanomaterial is expected to find potential applications in several fields including separation science and biomedicine.