Fabrication And Characterization Of Magnetic Carbon Nanotubes Composite Carrier For Tumor-targeted Therapy

The preparation, surface modification and basic application of carbon nanotubes (CNTs)-based magnetic composite particles were systematically studied in this paper. The research contained the preparation of magnetic nanocomposite particles such as Fe3O4/CNTs,CoFe2O4/CNTs and NiFe2O4/CNTs, the amino functionalization of nano-CoFe2O4/CNTs magnetic composite particles, the preparation and characterization of functional magnetic nanocomposite particles for magnetic targeting hyperthermia and radiotherapy. This work laid a good foundation for the application of CNTs-based magnetic composite particles in magnetic targeted therapy of cancer. The details were described as below:Firstly, the plum-shaped Fe3O4/CNTs, hydrophilic Fe3O4/CNTs and monodispersed Fe3O4/CNTs, CoFe2O4/CNTs, NiFe2O4/CNTs magnetic nanocomposite particles were separately prepared by glycol-solvothermal method and polyol method. The synthesized products were characterized by XRD, TEM, FTIR, XPS, VSM, and so on. The results showed that the plum-shaped Fe3O4/CNTs and lipophilic Fe3O4/CNTs nano-magnetic composite particles which were prepared by ethylene glycol Solvothermal, Fe3O4 nanoparticles were firmly attached on the surface of CNTs like plum-shaped or para-spherical. And the Fe3O4 nanoparticles prepared with uniform size and good crystalline. Magnetic property tests showed that the saturation magnetization reached 70.7 emug-1 and 50.0 emu·g-1, respectively, showing good magnetic responsiveness and superparamagnetism. The Me2Fe2O4/CNTs (Me=Fe,Co,Ni) magnetic nanocomposite particles prepared by polyol method, of which the coating was dense and uniform, had good monodispersibility, strong magnetic responsiveness and superparamagnetism. According to actual needs, monodispersed Fe3O4/CNTs, CoFe2O4/CNTs, NiFe2O4/CNTs magnetic nanocomposite particles with different coating density and magnetic properties were prepared by controlling the reaction conditions. Magnetic property tests showed that the saturation magnetization of them are 30.6,39.5 and 36.4 emu·g-1 at the optimum coating amount, respectively.Secondly, the structures, morphologies and magnetic responsive properties of CNTs-based magnetic nanocomposite particles prepared by different method have been analyzed and compared. By contrast, the result showed that the CoFe2O4/CNTs magnetic nanocomposite particles with the best properties were more fit as a follow-modified carrier material. The one-dimensional SiO2/CoFe2O4/CNTs magnetic nanocomposite particles with uniform and controllable coating layer of SiO2 were prepared by a sol-gel method using TEOS as a precursor modifier. Subsequently, the SiO2/CoFe2O4/CNTs magnetic nanocomposite particles were further functionalized by y-aminopropyl trimethoxysilane (APTES), and then the amino-modified magnetic nanocomposite particles were prepared. The structures, compositions and magnetic properties of modified composite particles were characterized and analyzed by XRD, FTIR, XPS, VSM, et al.Finally, the basic preliminary study based on magnetic targeted hyperthermia and radiotherapy was carried out. On the magnetic targeted hyperthermia, the folic acid was grafted on the surface of amino-modified SiO2/CoFe2O4/CNTs magnetic nanocomposite particles through amidation reaction. The use of folate receptor is highly expressed in cancerous tissue, but in most normal tissues almost no expression, while the dual targeted drug carrier with magnetic target and specifically biological target were prepared; on the magnetic targeted radiotherapy, first of all, the histidine were grafted on the surface of amino-modified SiO2/CoFe2O4/CNTs magnetic nanocomposite particles, then the compound was prepared under anhydrous oxygen-free conditions. When the [N(Et)4][Re(CO)3Br3] was dissolved in the water, the rhenium carbonyl compound precursor fac-[Re(CO)3(H2O)3]+were synthesized. At last, the rhenium carbonyl analog marking experiment based on magnetic targeted radiotherapy were carried out through coordinate reaction between the imidazole group of histidine and general three carbonyl rhenium. The analog marking rate of rhenium calculated by ultraviolet absorbance spectrophotometer was 80.85%, and the saturation magnetization value after marking is 14.7 emu·g-1. The result showed that it remained good magnetic property. The above elementary researches offer the theoretical basis and experimental foundation for the follow-up successful marking of radioactive nuclear 188Re on the magnetic nanocomposite particles which were immobilized by histidine.