【作者】 谢佳；

【导师】 周先礼； 鲁雄；

【作者基本信息】 西南交通大学 ， 微生物与生化药学， 2010， 硕士

【摘要】 制备具有微图形的材料基底来控制细胞的行为已经成为了生物医学工程领域的研究热点。多种细胞可以响应微米尺度,甚至于纳米尺度的材料表面拓扑结构,细胞的形态、取向、生长和分化亦受到表面结构的影响。复合微图形就能实现这样的目标,复合微图形是指将两种或多种类型的分子共同结合在同一块基底上,利用其不同的化学性质,产生不同的作用,达到利用同一块材料能产生不同功效的目的。本研究采用软刻蚀技术在硅表面制备出规则的,有序的,两种成分复合的壳聚糖/牛血清白蛋白(CS/BSA)复合微图形。壳聚糖作为自然界中唯一的碱性多糖,具有良好的生物降解性、可再生性和抗菌性。牛血清白蛋白具有较好的生物相容性。在软刻蚀中,用聚二甲基硅氧烷(PDMS)复制具有微图形的硅模板,得到具有微沟槽和点状图案PDMS弹性印章。采用微转移模塑法和复制模塑法制备CS/BSA复合微图形、BSA沟槽、CS沟槽微图形及点状微图形。利用抗菌实验来评价CS/BSA复合微图形的抗菌效果。结果表明,CS/BSA复合微图形对大肠杆菌和白色葡萄球菌都有着一定的抗菌能力,抗菌率在30%左右。体外成骨细胞培养实验表明CS/BSA复合微图形能在细胞生长初期约束细胞的生长方向,并且会先选择粘附在复合微图形中的CS区域,之后才逐渐铺展到BSA区域。BSA沟槽和CS沟槽对细胞生长方向有很强的诱导力。由于微图形凸起的影响,细胞会首先吸附在微图形脊上,并沿着微图形的方向生长,随后铺展到微图形的底部。小尺寸沟槽对细胞生长方向的诱导作用较强。沟槽微图形表面细胞的增殖和分化能力弱于平板样品表面,强于点状微图形表面；BSA比CS利于细胞增殖和分化。更多还原

【Abstract】 Controlling cell orientation and morphology by micropatterned substrates is one of hot topic in biomedical engineering. Cells can respond to micrometer scale, and even nano-scale, surface topography. Cell shape, orientation, growth and differentiation are also affected by surface texture of materials. Composite micropatterns were multifunctional biomaterials that co-patterned two or more types of molecules on one substrate. Thus, it can employ the advantage of components.In this study, we developed a new process that can prepare chitosan/bovine serum albumin (CS/BSA) composite micropatterns by soft-lithography on silicon substrates. CS is a basic polysaccharide in the nature that has good biodegradability, renewable ability and antibacterial ability. BSA is a serum protein that has numerous biochemical applications. Polydimethylsiloxane (PDMS) microstamps were used to transfer micropatterns from the micromachined silicon mold to the hydroxylated silicon wafers. CS/BSA composite micropatterns, BSA micropatterns and CS micropatterns were successfully fabricated on silicon surfaces by micro-transfer molding and replica molding technique.The antibacterial test was used to evaluate the antibacterial effect of CS/BSA composite micropatterns. The results showed that the CS/BSA composite micropatterns were effectively against two types of bacteria, Escherichia coli and Staphylococcus albus. The osteoblast (Sprague-Dawley rat) culture indicated that CS/BSA composite micropatterns could strongly influence cell behavior. Cells selectively adhered in the CS region at intial culturing stage, and then they gradually spread to the BSA region. The microgrooved surfaces had strong contact guidance effect on cell orentation. Cells tended to be parallel to the microgrooves when they were cultured on BSA microgrooves and CS microgrooves surfaces, They began to attach on the ridges of microgrooves, grew along the direction of microgrooves, and then spread to the bottom of microgrooves. This tendency was stronger on the microgrooves with smaller width. The cells on plane samples had random growth directions. The proliferation and differential rate of cells on microgrooved surfaces is lower than that on plane surface and higher than that on microdot-patterned surfaces, which indicated that micropatterns had complicated effects on cell behaviors. This study provides valuable guidance for the design of the biomaterial surfaces.更多还原