The Preparation Of The Muitifunctional Drug-loading Silica Materials

In this dissertation, magnetic nanocrystals Fe₃O₄ were prepared by co-precipitation method, and the magnetic mesoporous silica particles Fe₃O₄@m SiO₂ were synthesized by sol-gel method. Then the magnetic nanocomposite was characterized by scanning electron microscop?SEM?, transmission electron microscopy?TEM?, X-ray diffraction?XRD?, N2adsorption-desorption, thermogravlinetric analysis?TG? and Fourier-transform infrared spectroscopy?FT-IR?. The results show that the magnetic mesoporous composite material has a large specific surface area, pore volume and good morphology. Subsequently, the magnetic mesoporous composite materials were modified functionaly for the purposes of drug-loading in the following two aspects.On the one hand, in order to obtain a drug delivery system, which has the ability to target tumor cells, the Fe₃O₄@mSiO₂ was modified by APTES. And then, hyaluronic acid?HA? was covalently linked to the surface of Fe₃O₄@mSiO₂ through amidation reaction as targeting ligands. In order to possess more excellent performance, the HA modified magnetic mesoporous silica was further to react with the adipate hydrazide ADH as the coupling agent and the desired device MMSN-HA-ADH was prepared. Finally, structure and properties of MMSN-HA-ADH were characterized by FT-IR, UV-vis, XRD, TG-DTG and simulation experiments were carried out in vitro. The results show that we are prepared carrier with good thermal stability, high drug loading, high encapsulation efficiency and also a good ability controled release of drug.On the other hand, MMSN-NH2 was activated by butanedioic anhydride firstly and then zinc phthalocyanine?ZnPc?, a photosensitizer in photodynamic therapy, was attached to the surface of MMSN-COOH by linking the carboxyl group with the amino group of ZnPc through amidation reaction. Subsequently, the Structure of MMSN-Pc was confirmed by FT-IR, UV Vis, XRD, TG-DTG. Finally, the ability of MMSN-Pc to produce different reactive oxygen species under the condition of visible light irradiation was illustrated by the produce of the singlet oxygen and the decolorization reaction of Rhodamine B. The active oxygen species produced by MMSN-Pc is the key factor to kill cancer cells.