【作者】 焦延鹏；

【导师】 周长忍；

【作者基本信息】 暨南大学 ， 生物医学工程， 2006， 博士

【摘要】 通过物理、化学、生物等各种技术手段改善材料表面性能，可大幅度提高生物材料与生物体的相容性，是促进材料表面与生物体之间的有利相互作用、抑制不利相互作用的关键途径。本研究以聚乳酸材料为基材，对其表面进行功能化设计，研究功能化表面对蛋白分子吸附／解吸附性能和细胞／组织相容性的影响。 本研究采用碱水解处理和氨等离子体处理的方法、表面截留法和体外生物矿化的原理在聚乳酸材料表面得到3类功能化的表面：小分子活性基团功能化的表面；生物大分子仿生修饰的表面；钙磷涂层修饰的表面。通过各种分析技术对功能化表面的物理化学性能进行了表征。研究结果表明，在小分子活性基团功能化过程中，通过控制表面处理的条件（碱浓度、水解时间，处理功率、处理时间），可以控制材料表面的亲水性、活性基团密度和表面粗糙度。生物大分子仿生修饰研究结果表明，通过表面截留技术成功地得到壳聚糖、羧甲基壳聚糖、亚甲基磷酸化壳聚糖，肝素，透明质酸和硫酸软骨素修饰的聚乳酸表面。在聚乳酸表面钙磷涂层修饰实验中，羧基化的聚乳酸表面够较快的诱导聚乳酸表面钙磷涂层的生成，生成的钙磷涂层由具有纳米尺寸的晶体构成的基质和颗粒组成，钙磷涂层的主要成份是结晶比较松散的羟基磷灰石。 在生物相容性研究中，研究的主要内容是细胞和组织相容性，而对于其基础——蛋白质的吸附研究的很少，然而从生物学角度来说，细胞在生物材料表面的粘附，增殖以及分化是由蛋白介导的，考察材料的表面对蛋白吸附／解吸附性能的影响对于提高细胞／组织相容性的认识具有重要意义。本研究以功能化的聚乳酸表面为基础，选择与细胞粘附最相关的3种蛋白（纤粘连蛋白Fn，层粘连蛋白Ln，玻粘连蛋白Vn）用于吸附／解吸附性能研究。采用¹²⁵I同位素标记的方法，研究了3种蛋白在功能化聚乳酸表面上的吸附／解吸附性能。首先，分别考察了3种蛋白在不同功能化表面等温吸附和吸附动力学。其次，研究了不同浓度牛血清白蛋白（BSA）、胎牛血清（FCA）和3种蛋白在功能化聚乳酸表面的竞争吸附性能。最后，对吸附在功能化聚乳酸表面的3种蛋白在BSA溶液中的解吸附性能进行了研究。单一蛋白的等温吸附和吸附动力学研究表明，在本实验的浓度和时间范围内，蛋白浓度和功能化的表面对蛋白平衡吸附量和吸附速率的影响很大；其次，BSA和血清的加入竞争性的减少了功能化表面对蛋白的吸附，且随BSA和血更多还原

【Abstract】 Interaction between biomaterials and tissues occurs via a layer of proteins adsorbed at the surface of biomaterials, which is the immediate event occurring on its first contact with biological fluids and tissues. The nature and amount of the protein or polysaccharide adsorption layer depends on material surface properties, such as wettability, polar or ionic interactions, chemical structures and topography of the surface. The surface determines essentially the biocompatibility whereas the bulk decides the physical, mechanical properties required of an implant. In this study, the surface of poly(L-lactic acid) (PLLA) was functionalized to improve its biocompatibility. The effects of the functional surfaces on the absorption/desorption property of proteins and on cell/tissue compatibility were investigated.Three kinds of functional PLLA surfaces were gained by alkaline hydrolysis and ammonia plasma treatments, entrapment method and biomineralization principle. The active carboxy and amido, six kinds of biomacromolecules (i.e., chitosan, carboxymethyl chitosan, methylene phosphochitosan, herapin, hyaluronic acid and chondroitin sulfate), and calcium-phosphorus coatings were introduced to functionalize PLLA surfaces. Many techniques were used to character the functional surfaces, and the results showed that the hydrophilicity, the density of active groups and the roughness of PLLA functional surfaces could be controlled by adjusting the modification conditions, such as the NaOH concentrations, the hydrolysis times and the plasma treatment powers and times. The x-ray photoelectron spectroscopy (XPS) analysis results showed that it was successful to get the biomacromolecules modified surfaces by means of the entrapment method. The SEM and AFM observation results showed that carboxylated PLLA surface could improve the building rate of the calcium-phosphorus coatings, which included matrix and granule with nano-scale structure. The component of the calcium-phosphorus coatings was apatite with rather loosing crystal by means of X-ray diffraction (XRD) analysis.In the research of the effect of functional surfaces on the adsorption/desorption更多还原