Synthesis Of Thermo-sensitive, Magnetic And Fluorescent Composites For Drug Delivery And The Drug-loading, Releasing Experiment

Because chemotherapy has side effects on the tissue organs of human bodies in tumor treatments, the paper aims to study a method for targeted cancer therapy drug carrier by targeting, tracing and controlled drug-releasing, so as to reduce the side effects of chemotherapy drugs and relief the cancer patients. Based on this, the paper systematically carried out the following experiment:Firstly, Fe3O4magnetic nanoparticles (MNPs) with controlled morphology and uniform disperation were obtained by a modified thermal decomposition method useing oleic acid and oleylamine, as surfactant and reducing agent. The as-prepared samples were characterized by means of transmission electron microscopy and X-ray diffraction test. The results showed that, the shape of Fe3O4particles can be tuned by the ratio of the amount of oleic acid and oleylamine. When the ratio was2:4, the particles were monodisperse and spherical, so that they were suitable for next step. And Fourier-transform infrared analysis and thermogravimetric analysis were performed to characterize the crystallinity and surface nature of the resulting Fe3O4MNPs, in order to reveal the possible formation mechanism.Secondly, monodisperse Fe3O4magnetic nanoparticles were seleted within all the particles prepared in last chapter. Based on the selected monodisperse Fe3O4magnetic core, Fe3O4/ZnS magnetic fluorescent composite particles (FMNPs) were fabricated by a facile hot-solvent approach with trioctyl phosphine oxide as an ion-trapping agent. From TEM photos, it can be seen that the small ZnS particles loaded on the magnetic core relies on the ion-trapping agent, forming a heterojunction connecting structure. EDS and XPS tests confirmed the presence of ZnS particles on the surface. And then, the magnetic properties of the sample and the light emitting properties were tested. The results showed that the as-prepared composite particles had good magnetic responseive and fluorescence properties.Furthermore, through a soap-free emulsion method, polymer-coated magnetic fluorescent composite microspheres, the PNIPAM@Fe3O4/ZnS (PFMNPs) were obtained. Poly(N-isopropylacrylamide)(PNIPAM) is a thermo-sensitive material, which makes the microspheres thermo-sensitive as well. Moreover, the water-solubility of the PNIPAM improves the biocompatibility of the microspheres, and makes the material suitable for applications in vivo.Finally, the drug-loading and releasing experiments were carried out on the basis of tri-functional thermo-sensitive magnetic fluorescent microspheres. A MTT assay was used to characterize the biocompatibility of the carrier and the toxic effect on cancer cells.