Modification of magnetic silica/iron oxide nanocomposites with fluorescent polymethacrylic acid for cancer targeting and drug delivery

Biocompatible and water-soluble magnetic nanoparticles with mesoporous core-shell structure were prepared and successfully modified with a fluorescent polymer chain as a labelling segment and folic acid as the cancer targeting moiety and loaded with a drug for directional release. The porous silica oxide structure and long molecular chains of polymethacrylic acid embedded the drug efficiently in the nanocomposites and did not affect the magnetic properties of the carrier. Sustained release of the loaded drug was observed over 100 h under in vitro conditions. Furthermore, the drug carrier is able to drill into the cell membranes and obtain a sustained release of the anticancer drug into the cytoplasm. The in vitro cellular uptake of the drug demonstrated that the drug-loaded nanocomposites could effectively target the tumor cells. Our model experiments indicated that this multifunctional mesoporous core-shell magnetic nanoparticle can be exploited as an anticancer drug delivery vehicle for targeting and therapy applications.