A novel core-shell structured magnetic organic-inorganic nanohybrid involving drug-intercalated layered double hydroxides coated on a magnesium ferrite core for magnetically controlled drug release

A novel magnetic nanohybrid involving non-steroid anti-inflammatory drug diclofenac (DIC) intercalated Mg-Al layered double hydroxides (LDH) coated on magnesium ferrite particles was assembled via a one step coprecipitation self-assembly method. The XRD, FT-IR and ICP measurements reveal that the magnetic nanohybrid consists of both DIC-LDH nanocrystallite and magnesium ferrite phases. The TEM image shows that the magnetic nanohybrid presents well-defined core-shell structure with diameter in the range of 90-150 nm. Compared to pure DIC-LDH, an obviously smaller dimension and less sharp hexagonal morphology of the coated DIC-LDH nanocrystallites in magnetic hybrids is observed due to a heterogeneous nucleation and crystal growth process with the introduction of the magnetic core. The in vitro drug release rate of the magnetic nanohybrid was thus enhanced owing to the much smaller size of the coated DIC-LDH nanoparticles on the surface of the magnetic core. However, under an external magnetic field of 0.15 Tesla, the drug release rate of the magnetic nanohybrid decreases dramatically owing to the aggregation of the magnetic nanohybrid particles triggered by non-contact magnetic force. The kinetic data reveal that the release of DIC from the magnetic nanohybrid is controlled by particle diffusion, and the release rate is mainly affected by the particle size and the aggregation extent of the hybrid magnetic particles. Additionally, the obtained nanohybrid has a strong magnetization response, implying the possibility of application in magnetic drug targeting.