Effects of surface modification on the properties of magnetic nanoparticles/PLA composite drug carriers and in vitro controlled release study

Biodegradable polylactide (PLA) microspheres containing magnetic nanoparticles (MNPs) and anti-inflammatory drug Ibuprofen (IBF) were synthesized by using emulsion solvent evaporation technology. With surface modification, the magnetic nanoparticles/PLA composite drug carriers showed excellent magnetite content and magnetic susceptibility. SEM and TEM showed that the magnetic microspheres were spherical in shape with a smooth surface, and of a mean diameter in the micrometer range. The incorporation of MNPs and IBF into the PLA matrix was confirmed by FTIR. XRD and VSM further confirmed the existence of MNPs in the microspheres which maintained superparamagnetic behavior with a saturation magnetization of 31.4 emu/g. The magnetite content of 28.4 wt% was assessed by TGA. In addition, the drug release profiles showed that the IBF-loaded PLA magnetic microspheres are pH-induced release of IBF and are promising for controlled release drug delivery.