Synthesis and in vitro evaluation of pH-sensitive magnetic nanocomposites as methotrexate delivery system for targeted cancer therapy

This study focuses on the synthesis and in vitro evaluation of magnetic nanocomposites (Fe 3 O 4 @LDH) as methotrexate (MTX) delivery system for targeted anticancer therapy. In which, the Fe 3 O 4 nanoparticles acted as magnetically responsive carriers; the coating layer of layered double hydroxide (LDH) was used as a storehouse for MTX. The prepared Fe 3 O 4 @LDH nanocomposites exhibited a suitable size, good stability and magnetic responsibility (M s 36.66   emu/g); MTX successfully intercalated into the LDH of Fe 3 O 4 @LDH at an entrapment rate (%) of 91.78% (the drug loading was 18.36%) by host-guest exchange process. Moreover, the release studies in vitro showed that the drug delivery system (Fe 3 O 4 @LDH-MTX) had excellent pH-sensitivity, 84.94% of MTX was released within 48   h at pH   3.5 via the co-effect of dissolution of LDH layer and ion-exchange. WST-1 assays in cancer cells (MCF-7 and HepG2) and normal cells (HUVEC) demonstrated that Fe 3 O 4 @LDH-MTX exhibited high anticancer activity while low toxicity to normal cells, and also the Fe 3 O 4 @LDH composites were practically non-toxic. Thus, our results revealed that Fe 3 O 4 @LDH-MTX would be a competitive candidate for targeted delivery and sustained and controlled release of MTX.