LAUSR

Abstract The design of a drug delivery system capable of a pH-responsive controlled 5-fluorouracil anticancer drug release to cancer sites is one of the important options to reduce the well documented side effects of this drug. La 0.7 Sr 0.3 MnO 3 (LSMO) magnetic nanoparticles (MNPs) were synthesized by solution combustion synthesis and the optimized MNPs were coated with silica. X-ray diffraction patterns reveal that the crystal structure is a single perovskite phase which was unchanged after silica coating. Silica coating on LSMO was found to reduce the nanoparticle crystallite and magnetic properties. The silica surface of LSMO MNPs was functionalized to confer a pH-dependent switchable surface and was used to demonstrate the pH-responsive controlled release of 5-FU anticancer drug which was significantly higher than the 5-FU released from silica coated LSMO MNPs that were not functionalized. The in-vitro release studies show that only 11.36% of 5-FU was released at pH 7.4 (mimic of the physiological environment) and 37.20% at pH 5.0 (mimic of the intracellular organelles of cancer cells). The pH-responsive release of this functionalized silica coated LSMO MNPs suggest that it could be used in the controlled release of 5-FU anticancer drug at tumor sites.