“…Many types of novel MTX delivery systems have been reported, such as nanoparticles [7][8][9], microspheres [10], liposomes [11], polymeric micelles [12] and miscellaneous multiparticulate systems [13]. Among these, nanoparticles, especially the magnetic iron oxide (Fe3O4) nanoparticles seem to be a promising tool for site specific delivery [14,15], based on the fact that they will release the anticancer drug on tumor cells owing to the enhanced permeability and retention (EPR) effect [16,17] and passive drug targeting. Furthermore, recently layered double hydroxide (LDH) nanoparticles have been proven effective for site-specific delivery of anticancer drugs to tumor and reduce its side effects, due to their inherent properties such as high biocompatibility [18], low cytotoxicity [19], the ability to accommodate various biologically important molecules including genes and drugs [20][21][22], and the partial dissolution of LDH layers in endosome that not only stops the passive control release of drugs, but also buffers the excess protons, which helps the drugs to escape from endosome, improves the viability of drugs in cytoplasm, and enhances the delivery efficacy [23].…”