Synthesis Of Mesoporous Silica Microparticles As Drug Carriers And Carolline-Shaped Mn₂O₃Catalysts And Their Properties

Owing to the unique mesostructure features and drug loading and sustained-release profiles, the application research on mesoporous silica nanomaterials (MSN) in the biomedical field has attracted broad attention. The in-depth exploitation of their applications in biomedical field becomes one of the current hot research focuses. Under this background, this thesis focused on the synthesis and functionalization of MSN. We explored a controllable preparation method of MSN based on long chain organosilane and the further magnetic functionalization of the prepared MSN. The drug storage and release behaviors of the prepared MSN were also investigated, as well as its biomedical effect. During the exploring the method of removing the organic pore template, a facile route for the preparation of Mn2O3hierarchical materials with a coralline shape was incidentaly found out. The catalytic properties of the prepared Mn2O3in methylene blue degradation were investigated in detail.Uniform and monodispersed mesoporous silica nanospheres were synthesized using a long chain organosilane, C18TMS, as both pore template and silica source co-condensing with TEOS. The particle size can be tuned in the range of80-300nm by changing the amount of multi-silica precursors, while the pore diameter can be regulated from2.0to4.6nm by adjusting the molar ratio of water to ethanol. The synthesized MSNs showed excellent drug loading and pH responsive releasing effects. The maximum loading capacity for anti-cancer medicine, Doxorubicine, is162mg DOX/g MSN, and the sustained release can last for more than100hours with the maximum release amount of more than70%. The as-prepared MSN has a very good biocompatability towards humanbreast cancer MCF-7cells and normal fibroblast L929cells. The drug loaded system can be phagocytosed by tumor tissues cell via endocytosis, the acidic environment in cytoplasma triggered the release of DOX.Via the nucleophilic substitution between-Br on Fe3O4and-NH2existed on the MSN surfaces, we succefully grafted Fe3O4onto MSN and a satellite-like MSN-Fe3O4microcomposites was obtained. Under the external magnetic field, the MSN-Fe3O4microcomposites presented a passive movement property, which showed the promising in fields of targeted drug delivery and magnetic resonance imaging.Coralline-like Mn2O3with high catalytic effects for degradation of organic pollutants methylene blue was synthesied via simple acidic potassium permanganate oxidation and calcination method. The influence of pH value, H2O2concentration and different treating manners on the discoloration efficiency of methylene blue aqueous solution was investigated. At different pH value of3,7,9, and different H2O2concentration between50mM and900mM, all samples showed excellent degradation efficiencies. Under the same reacting condition, the discoloration effect of aging treatment after stirring for a short while then separated with Mn2O3is much better than continuous stir with catalysts. The overall discolorization rate with the existence of Mn2O3is above90%, and the maximum degradation efficiency recorded in the UV-vis instrument can achieve to100%.