【作者】 郑辉；

【导师】 欧阳健明；

【作者基本信息】 暨南大学 ， 无机化学， 2006， 硕士

【摘要】 本论文首次采用草酸钾损伤形成的缺陷LB膜作为受损伤肾上皮细胞膜的模型，采用扫描电子显微镜(SEM)、原子力显微镜(AFM)、X射线衍射(XRD)等表征方法，从分子和超分子的水平上研究LB膜缺陷的微结构及其对CaOxa晶体成核、生长和沉积图形的影响。 DPPC LB膜经草酸钾处理后形成的缺陷LB膜能诱导生成大量圈状—水草酸钙(COM)晶体图形，相比之下，没有经草酸钾处理的LB膜只诱导零散的六边形COM晶体。构成圈状图形的草酸钙晶体主要以针状COM的为主，其原因是由LB膜中的圈状缺陷诱导所致。 缺陷LB膜在0.3mmol／L的草酸钙亚稳溶液中生长20分钟就可观测到圈状晶体图形，而常规LB膜在1小时后才有晶体，普通水溶液要6小时，促进COM晶体的异相成核的强度依次为：缺陷LB膜＞常规LB膜＞无LB膜水溶液。 生长时间影响圈状图形的形貌和数量。随着生长时间增加，空心的圈状COM晶体图形转变为实心的圆形晶体图形，不同尺寸的实心圈状晶体图形的比例增加，圈内单个COM晶体的尺寸明显增大。同时小尺寸(5-20μm)的圈状晶体图形比例增加，而大尺寸(＞50μm)的圈状图形比例减少，中等尺寸的(20-50μm)的没有明显的变化。 损伤LB膜的草酸钾浓度对圈状晶体图形有明显影响。随着草酸盐浓度的增加，圈状晶体图形里面的COM变得越来越稀少。图形由0.3mmol／L时的实心圆形逐渐变成5.0mmol／L的环状晶体图形。圈状图形里面的COM数量为0.3＞0.6＞2.5＞5.0。同时圈状晶体图形的数量增多，其规律为：5.0＞2.5＞0.6＞0.3。 增加LB膜在干燥器中放置时间，缺陷LB膜能诱导生成带孔的圈状草酸钙晶体图形。归因于LB膜中的DPPC分子重排，造成堆积结构发生变化。 这些结果有助于在分子和超分子的水平上阐明肾上皮细胞膜损伤后诱导肾结石形成的的分子机制。更多还原

【Abstract】 The circular patterns of calcium oxalate (CaOxa) crystals were first induced at defective sites of Langmuir-Blodgett film of dipalmitoylphosphatidylcholine (DPPC) injured by potassium oxalate. This model system might be used to mimic formation of calcium oxalate (CaOxa) stones at surface of damaged renal epithelial membranes, microcosmic structure of defective LB films in the points of molecular and supramolecular level and the circular patterns of CaOxa crystals which induced by defective LB films were observed by Atomic Force Microscope(AFM), Scanning electronic microscope (SEM) and X-ray diffraction (XRD).The defective LB film of DPPC which injured by potassium oxalate can induce a lot of ring-shaped and solid circular patterns of calcium oxalate monohydrate (COM) crystals, and the crystal is mainly in needle shape with a small part being in forms of hexagonal or quadrangle. By comparison, the LB films without oxalate pretreatment only induced randomly growth of hexagonal COM crystals. In 0.3 mmol/L calcium oxalate solution, the circular patterns induced by defective LB film can be observed in 20 minutes. However, conventional LB films crystalise until an hour later, in bulk solution needs 6 hours. So, the ability to induce COM is: defective LB film conventional LB films> bulk solution.The crystallization time has an apparent effect on the shape and quantity of circular patterns of COM. As crystallization time increases, ringy patterns of COM transfer into solid circular shape, and the ratios of Solid circle patterns in different sizes is increasing. The size of single COM crystal in the circle patterns enlarge evidently. The ratios of small size(5-20 μm) circle patterns multiply, and the medium size (20-50 μm) show slight change; however, the number of big size (>50μm) decrease.The concentration of potassium oxalate which injure LB films has an obvious effect to circular patterns of COM. With increasing the concentration of oxalate, the COM in circle patterns will become thinner and thinner. Gradually, the solid circle patterns in 0.3 mmol/L will become ringy patterns in 5.0 mmol/L. The number of COM in circle patterns is 0.3>0.6>2.5>5.0 . Meanwhile, the number of circle patterns increases, and its rule is 5.0>2.5>0.6>0.3.Increasing the time placed in desiccator, defective LB film can induce circular patterns of COM with many holes.The results would shed light on the molecular mechanism of structure change in renal epitheial membrane injured by oxalate at the molecular and supremolecular level, and on the relationship between urolithiasis and the injury of renal epitheial membrane.更多还原