Synthesis, characterization, and sustained release property of Fe3O4@(enrofloxacin-layered double hydroxides) nanocomposite.

A novel magnetic nanocomposite with enrofloxacin (ENR) intercalated MgAl layered double hydroxides (LDH) coated on Fe3O4 particles, denoted as Fe3O4@(ENR-LDH), was assembled via a delamination-reassembling process. Fe3O4@(ENR-LDH) was characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, element chemical analysis, transmission electron microscopy, differential scanning calorimetry, and room-temperature magnetic measurements. Results showed the following: ① Fe3O4@(ENR-LDH) consisted of both ENR-LDH nanocrystallite and Fe3O4 phases; ② Fe3O4@(ENR-LDH) presented well-defined core-shell structure with diameter in the range of 15-20nm; ③ the thermal stability of ENR was enhanced after intercalation; and ④ Fe3O4@(ENR-LDH) exhibited good superparamagnetism. The release kinetics of ENR was investigated in buffer solutions at pH4.6 and 7.2, and the release process fitted Bhaskar model indicating diffusion-controlled mechanism. In addition, ENR release rate from Fe3O4@(ENR-LDH) was remarkably lower than that from the corresponding physical mixture, showing that Fe3O4@(ENR-LDH) can be considered as a potential magnetic targeting drug delivery-controlled-release system.