蛋白—纳米金杂化微结构在药物载体和生物支架材料中的研究

【作者】 杜博；

【导师】 张其清；

【作者基本信息】 北京协和医学院 ， 生物医学工程， 2013， 博士

【摘要】 蛋白基材料具有良好的生物相容性、生物降解性并易于功能化修饰,在药物载体及功能化生物材料构建方面已经引起广泛关注。纳米金具有独特的理化性质及良好的生物相容性,广泛用于光热疗、成像、传感器、药物和基因载体等研究领域。随着多功能材料越来越受到重视,杂化材料因其特有的功能在药物传递及其它医学领域显示出重要的应用前景,因此,亟需开展新型有机-无机杂化材料的合成研究。本论文选用丝素蛋白和牛血清白蛋白(BSA)作为有机材料,制备成微囊及花状微结构,并用金纳米球、纳米棒进行修饰,从而获得多功能杂化材料。主要获得了以下研究结果或结论：1.以丝素蛋白为壳层材料,不引入带正电的聚电解质,以PLGA微球为模板,用LBL法制备出了一系列不同层数的丝素蛋白单组分微囊。然后进一步制备出两种杂化微囊：1)壳层夹载金纳米棒的杂化微囊；2)表面结合DNA功能化纳米金的杂化微囊。杂化微囊具有控制释放、联合治疗、诊疗一体等多种应用潜能。2.以丝素蛋白为壳层材料,PLGA微球为模板,用去溶剂法制备出了丝素蛋白单组分微囊,并通过金纳米球、金纳米棒或两者同时修饰调节微囊的通透性。杂化微囊具有很强的拉曼增强性质,在诊疗一体化或光热疗-化疗联合治疗方面具有应用潜力。3.用去溶剂法成功制备了具有特殊拓扑结构的BSA花状微结构,每个结构单元由平行的BSA管状结构组成；其过程是蛋白沉积于花状的无机盐结晶上形成的；制备了负载模型药罗丹明B的BSA花状微结构,作为局部给药的载体。4.通过引入金纳米粒子以及RGD对上述BSA花状微结构的理化性质以及生物活性进行调控。得到的新型杂化材料具有独特的力学性质、几何结构、表面拓扑结构以及表面化学性质等,可用于细胞-材料界面相互作用、局部药物及细胞传递等的研究。综上所述,本研究用LBL、去溶剂法合成了丝素蛋白单组分微囊,再用功能化金纳米球和／或金纳米棒进行修饰,引入的DNA、金纳米粒子以及丝素赋予杂化微囊特有的性质使其可用于联合治疗、诊疗一体化及示踪等；用去溶剂法制备了BSA花状微结构,并沉积金纳米粒子、修饰RGD等。本研究制备的杂化微囊以及杂化花状微结构为药物、细胞传递奠定基础。更多还原

【Abstract】 Natural proteins have attracted great attention for construction of drug delivery vehicles and functionalized biomedical devices due to their good biocompatibility, biodegradability, and amenability to surface functionality. In addition, gold nanoparticles also gained interest for promising applications including photothermal therapy, biological imaging, sensors, drug and gene delivery systems because of their unique optical response and superior biocompatibility. With the increasing interest for multifunctional nanomaterials or devices in the biomedical field, it is necessary to synthesize novel organic-inorganic hybrid materials which offer additional special functions for drug delivery or other potential medical applications.In this dissertation, silk fibroin and bovine serum albumin (BSA) were chosen as the ideal proteins as organic materials. Subsequently, gold nanospheres and nanorods were synthesized to modify the organic microstructures including capsules and flower-like particles so as to obtain the hybrid multifunctional materials. The mains results are as follows:1. Single component silk capsules with different layers were synthesized from spherical PLGA templates using the layer-by-layer (LBL) technique, which can avoid the introduction of toxic cationic polyelectrolytes. More importantly, we further synthesized two kinds of hybrid capsules:1) gold nanoparticles inside both silk layers;2) DNA-modified gold nanoparticles on the surface. These hybrid capsules have promising applications for controlled release, combination therapy and theranostic medicine.2. Single component silk capsules were synthesized by desolvation method with the PLGA templates removal. The permeability of the capsules was investigated using fluorescence biomacromolecules as the tracer. Moreover, the shell permeability can be finely tuned using gold nanospheres or nanorods, even both of them together. Finally, these hybrid capsules offered distinct surface-enhanced Raman effect. These hybrid capsules can be used as the candidates for theranostic application or integrated therapy of photothermal and chemical therapy.3. BSA flower-like microstructures with special topography were prepared by desolvation method. We confirmed that the architecture of flower was composed of BSA tubes, which were formed via deposition on the flower-like inorganic salts crystal templates by following dissolution of them. Rhodamine B, a model drug, was loaded into flower-like microstructures, which demonstrated that these flower-like particles can be used in drug delivery systems, especially for local drug delivery to the inner ear. 4. The physicochemical and bioactive properties of the above mentioned BSA flower-like microstructures were manipulated by means of introduction of gold nanoparticles or RGD peptides. These novel hybrid microstructures with unique geometry, topology, mechanical and surface chemical properties can be used in future research on cell-material interactions or local drug or cell delivery.In summary, we synthesized single component silk capsules using LBL and desolvation technique, respectively. Subsequently, these silk capsules were modified with gold nanospheres or/and nanorods, which offer these hybrid capsules distinct functions and potential applications including combination therapy, theranostic medicine and trace imaging agen by introduction of DNA, gold and silk capsules. In addition, we prepared BSA flower-like microstructures by desolvation and modified them with deposition of gold nanoparticles and RGD. In one word, these hybrid materials including microcapsules and flower-like microstructures can serve as a basis of research on the potential drug or cell delivery.更多还原