【作者】 马豫峰；

【导师】 蔡继业；

【作者基本信息】 暨南大学 ， 无机化学， 2005， 硕士

【摘要】 在生物材料表面进行生物分子的自组装修饰,从而改善材料的生物相容性是近年发展起来的一个重要课题。本论文主要利用原子力显微镜、红外光谱等表征手段研究了壳聚糖/蛋白质/DNA体系的生物相容性,均取得了一些基础性的结果。 1.本论文选择多糖中最具代表性的壳聚糖作为基础,以血红蛋白和牛血清白蛋白为相对体,利用壳聚糖的良好生物相容性来研究壳聚糖与血红蛋白、壳聚糖与牛血清白蛋白之间的复合与吸附性能。对前者而言,制备了壳聚糖/血红蛋白复合膜,改变形成膜的不同条件(浓度、组装次数和pH值),运用原子力显微镜(AFM)和红外光谱对其结构进行了表征。实验结果表明血红蛋白溶液与pH为6的壳聚糖醋酸溶液复合制备的三循环膜结构紧密,壳聚糖和血红蛋白相互作用能较好的达到平衡。为临床应用壳聚糖对血红蛋白进行修饰来改进其作为血液替代品的缺陷方面做了一些基础性的探讨。 2.对壳聚糖与牛血清白蛋白的研究,主要是利用壳聚糖作为功能单体,在模板分子牛血清白蛋白的存在下,制备出具有特异识别功能的分子印迹聚合物。实验结果表明,科用壳聚糖制备的牛血清白蛋白分子印迹聚合物对牛血清白蛋白具有特异识别功能,显示出明显的印迹效果。这种特异性分子印迹介质的制备,为分离提纯特种结合蛋白提供了一种优良的方法,相信其在分离提纯领域将得到越来越广泛的运用。 3.本论文还通过改变实验条件研究了DNA的形貌;并对公认的致癌物Cr(Ⅵ)化合物对DNA损伤的过程进行了AFM表征,实验是在pH为5.6的条件下进行的体外研究,但其形态学和光谱学结果和医学结论是基本一致的,共同证明了单一六价铬不能致DNA损伤,而有还原剂谷胱甘肽存在时,六价铬可以与谷胱甘肽发生反应致DNA损伤,使DNA链断裂。本研究为开展DNA损伤的AFM观察进行了探索,并使进一步研究发生断裂的位点及断裂的修复情况等成为可能。 最后,本论文结合蛋白质与DNA相互作用的一些研究进展,对利用AFM如何开展这一领域的研究进行了一些概述,为今后深入开展相关研究确定了具体方向。更多还原

【Abstract】 The self-assembled modification of biomolecules on biomaterial, is an important task lately which can improve the biomaterial’s consistent property. The consistent property among chitosan, protein and DNA was studied by atomic force microscope(AFM), FTIR etc, and some basal results were found.Based on representative chitosan among polysaccharides, hemoglobin(Hb) and bovine serum albumm(BSA), the composite and adsorptive property between chitosan and Hb/BSA were studied using better compatibility of chitosan. Chitosan and Hb self-assembled into the composite films with various layers at various pH, whose structures were studied by AFM and FTIR. The results showed that there is better biocompatibility between chitosan and Hb, and that this preliminary research will provide theoretic base for studies on Hb as a blood substitute in clinical application. On the study of chitosan and BSA, the molecular imprinting polymer with differential discriminating function was made, which could be used on separation and purification of biomolecules.In addition, AFM was used to investigate ultrastructure of calf thymus DNA by changing experimental conditions. Furthermore, calf thymus DNA damage induced by potassium dichromate in combination with Glutathione(GSH) was studied by AFM and UV. The resuks supported the medical conclusion in morphology and spectrography that GSH can induce potassium dichromate to generate various tumor-inducing intermediate products. Last, the interaction between protein and DNA was summarized, which can orient the relative study, for the future.更多还原