Preparation And Drug-carried Research Of Fe₃O₄/MWNTs Magnetic Composites

Drug targeting treatment is emerging as the frontier field for the therapy cancer. Chelerythrine (CHE) is a novel molecule for hepatoma treatment. Magnetic targeting drug nanoparticles consist of anti-cancer agent, superparamagnetic materials and carriers, and possess the long circulating ability. When injected into body, they can accumulate at the target region under the magnetic field, and then drugs are released slowly to kill the tumor cell with low systematic toxicity. In this study, Fe3O4nanoparticles were chosen as magnetic materials, multi-walled carbon nanotubes (MWNTs) as the carriers, and chelerythrine as the targeted drug to prepare Fe3O4/MWNTs-CHE magnetic drugs system. It would provide reliable foundation for chelerythrine as a slow-release formulation of development and application. The major findings were summarized as follows:Firstly, the Fe3O4/MWNTs nanocomposites were fabricated by a facile hydrothermal method, choosing oxidized MWNTs as skeleton materials, FeSO4·7H2O as iron source. The synthesized products were characterized by FTIR, XRD, SEM, TEM, XPS, VSM, and possible reaction mechanism was discussed in detail. The results showed that Fe3O4nanoparticles with diameters in the range of15～30nm were firmly decorated on the external surfaces of MWNTs. And the Fe3O4nanoparticles prepared with uniform size and good crystalline. Magnetic property tests showed that the Fe3O4/MWNTs nanocomposites exhibited good ferromagnetic behavior with a high saturation magnetization of55.833emu/g and a coercivity of97.062G.Secondly, Fe3O4/MWNTs-CHE magnetic drugs system was prepared by adsorption method with CHE as the antitumor drug, and Fe3O4/MWNTs nanocomposites as the drug carrier. The effect of carrier/CHE ratio, CHE concentration, temperature on Fe3O4/MWNTs nanocomposites for its adsorption capacity was discussed. The prescription procedure was optimized by response surface methodology with drug loading content and encapsulation efficiency as synthetic indexes. When carrier/CHE ratio was20.6, CHE concentration was 172.0μg/ml, temperature was34.5℃, the drug loading content and entrapment efficiency were3.36%and69.76%, respectively.Finally, the release test in vitro of Fe3O4/MWNTs-CHE magnetic drugs system was conducted. The release profiles of CHE from the Fe3O4/CMCS-CHE magnetic drugs system were found to be biphasic with a burst release followed by a gradual release phase. The release time could last for about four days. And the releasing rate in acidic medium was quicker than in alkaline medium, all following the Higuchi matrix model and Retiger-Pepper matrix model.