【作者】 葛泉波；

【导师】 姚康德；

【作者基本信息】 天津大学 ， 材料学， 2005， 硕士

【摘要】 为了使生物材料表面生物化,本文以聚苯乙烯(PS)二维平面为模板研究了蛋白表面修饰技术,构建具有生物活性的生物材料表面。采用物理包被法依靠疏水作用在PS表面架构明胶、胶原和RGD(精氨酸-甘氨酸-天冬氨酸)多肽的生物活性层。通过光电子能谱(XPS)分析修饰表面的元素含量变化,N元素含量显著提高,说明蛋白分子在表面存在。Bradford方法定量分析明胶、胶原和RGD多肽的表面吸附量。采用高锰酸钾硫酸溶液对PS表面进行氧化反应,生成羧基位点,水溶性碳二亚胺活化羧基,接枝明胶、胶原和RGD多肽分子。XPS分析了表面N原子的引入,并对C1s分峰解析,存在酰胺键,确定蛋白分子是共价键合在PS表面。动态接触角下降显著,证明修饰表面的亲水性能提高。在明胶、胶原和RGD多肽修饰表面接种人表皮细胞,提高了细胞的黏附和增殖能力。明胶、胶原和RGD多肽这三种均具有RGD结构域的不同生物分子,对比考察其对细胞行为的影响。组织工程用生物材料最为关键的两个性能是力学性能和生物相容性。本文通过热缩聚法合成了壳聚糖(CS)-聚乳酸(PLA)的接枝共聚物(CL)。IR、NMR表征了CL的分子结构,本体相为壳聚糖,接枝相为聚乳酸。XPS分析了CL表面的元素组成,指出聚乳酸的链长与初始投料比LA/CS成正相关。动态接触角分析说明了CL接触水相时构象的变化。力学试验机测试了CL的干态、湿态强度以及断裂伸长率,与CS相比有较大提高。在CL上种植表皮细胞评价了细胞的黏附和增殖能力,CL-1.5膜细胞相容性良好。为了提高CL的细胞相容性,本文采用共混截留的思路,利用CL的溶胀性能引入并固定明胶和RGD多肽分子,接种家兔骨髓间充质干细胞(MSCs),考察MSCs在改性CL上的生长情况。明胶修饰的CL膜,其细胞相容性得到进一步提高。更多还原

【Abstract】 For bioactivating biomaterials surface, surface modification of 2D polystyrene (PS) with protein was studied. Firstly gelatin, collagen and Arginine-glycine-aspartic acid (RGD) peptide adsorbed to PS surfaces with physical reaction. XPS proved the increase of nitrogen content on the modified surfaces. Quantitative analysis of protein adsorption was done by Bradford method. Secondly, PS surfaces were carboxylated by permanganate oxidation in diluted sulfuric acid, and the carboxyls were activated with water-soluble carbodiimide to graft with gelatin, collagen and RGD peptide. XPS method confirmed the existence of nitrogen element from protein molecules. Further more, this paper parsed C1s charts. The results showed the presence of amido link (-CONH-) and covalently binding of proteins to PS surfaces. Dynamic contact angle measurement indicated hydrophilicity of PS surfaces was improved obviously after grafting modification. Thirdly, evaluated by epidermal cell culture, cell adhesion and proliferation was better on modified surfaces than the initial. This paper also compared the effect of these different protein molecules to cell behavior. Mechanical intension and biocompatibility are important factors of biomaterials used in Tissue Engineering. Chitosan-poly(lactic acid) copolymer (CS-LA, CL) was synthesized by thermal condensation polymerization. Main body was chitosan, and grafting phase was oligomer of lactic acid (PLA). IR and NMR spectra verified the occurrence of LA grafting in CL. XPS indicated that the length of PLA segments in CL structure increased with LA content. The change of CL conformation in water was analyzed with dynamic contact angle measurement. Mechanical properties of CL membranes were also done. In contrast of chitosan, intension and extension property of CL membranes were all improved due to PLA segment physical cross-linkage. Epidermal cell culture was performed to evaluate cytocompatibility of membranes. The results showed that cell adhesion and proliferation was effective on the surface of CL membranes especially CL-1.5. To improve CL’s cytocompatibility further, gelatin and RGD peptide were immobilized to CL by entrapment method. MSCs, cultured on the modified CL membranes, grew well and spread sufficiently especially the gelatin-modified.更多还原