【作者】 滕瑜；

【导师】 杨小平；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2012， 硕士

【摘要】 四氧化三铁是一种非常重要的磁性材料，尤其是纳米尺度的四氧化三铁因具有生物组织的相容性和与形貌尺寸相关的电磁性能，在生物及其医药领域得到了广泛应用。磷酸钙类生物陶瓷（CaP）具有与骨矿物质相近的组成和良好的生物相容性，主要包括羟基磷灰石（HA）、二水合磷酸氢钙（DCPD）、磷酸三钙（α-TCP，β-TCP）等。采用磷酸钙包覆的四氧化三铁纳米材料兼具了核层和壳层的性能，对于骨组织再生修复有重要意义。本论文利用水热法制备Fe₃O₄纳米磁性粒子，采用生物矿化法在Fe₃O₄表面包覆一层CaP生物陶瓷形成核壳纳米复合粒子。产物的结晶性能和组成成分、饱和磁化强度和磁性能、形貌和尺寸以及在水溶液中的分散性等性能分别通过XRD、VSM、SEM、TEM等表征分析。结果显示，水热法制备Fe₃O₄纳米磁性粒子时，提高反应温度、反应时间或分散剂PEG浓度可以提高产物的结晶性、磁性以及粒子尺寸。生物矿化法制备复合粒子时，采用两种不同矿化机理的5倍模拟人体体液（5SBF）分别制备了具有不同结晶形态和钙磷比的包覆层的Fe₃O₄@CaP复合磁性纳米粒子。将Fe₃O₄@CaP复合磁性纳米粒子与SD大鼠骨髓间质干细胞（BMSCs）共培养，采用CCK-8法和细胞摄入实验研究复合粒子对细胞的生物相容性。然后通过成骨诱导分化实验对与复合粒子共培养的细胞在3、7、14、21天下的ALP活性和钙离子含量进行测定。结果得出Fe₃O₄@CaP复合磁性纳米粒子有助于细胞的生长、增殖和分化。最后利用外加磁场作用将摄入Fe₃O₄@CaP复合磁性粒子的细胞制备成致密的细胞片（cell-sheet），有望作为骨组织工程无支架再生修复材料。更多还原

【Abstract】 Iron oxide, especially iron oxide nanoparticle, is a very importantmagnetic material. It has been widely used in biomedical field for itsbiocompatibility, electrology and magnetism properties, which relates toparticle dimension and morphology. Calcium phosphates compounds （CaPs）,such as hydroxyapatite （HA）, dicalcium pyrophosphate dehydrate （DCPD） andtricalcium phosphate （α-TCP，β-TCP） etc., are biological ceramics owing totheir good biocompatibility and similar compositions with natural boneminerals. To develop a kind of Iron oxide nanobbrids with CaP coating, wouldcombine both the features of core and shell materials, and have potentialapplications in bone tissue engineering.In this thesis, Fe₃O₄magnetic nanoparticles were obtained byhydrothermal method, and then coated with CaP compounds viabiomineralization to form core-shell nanohybrids. Properties includingcrystallinity, composition, saturation magnetization and magnetism,morphology and dimension, and dispersibility in water were measured and analyzed by techniques as XRD, VSM, SEM and TEM. The results showedthat the crystallinity, magnetism and dimension of products could be improvedby elevating reaction temperature, prolonging reaction time and increasing theconcentration of PEG. When subjected to biomineralization with simulatedbody fluid （SBF）, the produced Fe₃O₄@CaP nanohybrids resulted in differentcrystal morphology and calcium-phosphorus ratio, which apparently dependedon the SBF used.SD rats bone mesenchymal stem cells （BMSCs） were cultured in thepresence of Fe₃O₄@CaP nanohybrids at different amounts, CCK-8and cellintake experiment were performed to evaluate the biocompatibility ofFe₃O₄@CaP nanohybrids. Then ALP activity and the content of calcium ion ofthe BMSCs with Fe₃O₄@CaP nanohybrids intake, were determined at3,7,14and21day after osteogenetically induced differentiation. The results exhibitedFe₃O₄@CaP nanohybrids had good biocompatibility, and could promote cellproliferation and differentiation. With the aid of external magnetic field, theBMSCs with Fe₃O₄@CaP nanohybrids intake could be made into a sort ofcompact cell-sheet with several layers of cells. The cells in the cell-sheet wereconfirmed viable and the cell sheet was expected to be used as scaffold-freeregeneration material for bone defects.更多还原