基于酵母β-葡聚糖与蛋白质间的相互作用构建口服蛋白类药物载体及其功能研究

As a new class of drug with the characteristic of higher activity and specificity, lower toxicity, protein drugs have great advantages in treatment of many diseases，by comparison with traditional drugs. However, subcutaneous injection is the main method to deliver drugs due to the chemical structure and biological activity. Therefore，in this project, we aim to fabricate an oral delivery system by using water-insoluble yeast β-glucan particles, based on the multiple interactions in three dimensional scale between protein drugs and the β-glucan in inner cavity. By modulating the size of the cavity accordingly, the insulin, salmon calcitonin and human growth hormone, as the protein drug templates, were loaded into the cavity of the yeast β-glucan constructing the drug delivery system. Then, the interaction mechanism between drug molecules and the carrier, the remaining biological activity for protein drugs, insulin entrapment efficiency, loading efficiency and the release behavior under the different pH conditions both in vivo and intro, will be thoroughly investigated by means of 2D NMR, CD and Flow cytometry, et al. Meanwhile, taking the insulin carrier as the example, the synergistic effect on treatment of the skin fester in mice will be evaluated; Finally, the molecular recognition for yeast β-glucan by the right target receptors，and the transportation mechanism in body will also be revealed. Therefore, this work has important academic value and potential applications, which is expected to be screened a novel method for the protein drugs in oral administration.

蛋白类药物作为一类新型药物，相比传统药物，具有高活性、特异性强、低毒性等优点，在治疗疾病方面具有明显优势。然而，药物分子的结构与生物活性，限制其主要依赖皮下注射给药。由此，本项目基于蛋白药物分子与酵母β-葡聚糖在三维尺度上的多重相互作用，旨在利用酵母β-葡聚糖构建一种口服蛋白类药物载体。通过调控酵母β-葡聚糖颗粒的空腔尺寸大小，以胰岛素、鲑降钙素以及人生长激素为药物分子模板，构建口服蛋白类药物载体；通过二维核磁、圆二色谱以及流式细胞等测试手段，研究载体与药物分子之间的相互作用机制、载体对药物分子生物活性、负载量和包封率的影响，以及药物载体在体内外缓释行为以及血药调控效率；同时，以胰岛素为模板，考察药物载体在治疗糖尿病皮肤溃烂过程中的协同作用，并对载体的靶标受体作用及其体内转运机制进行探讨。本项目旨在提供一种新的方法构建一种新型的口服蛋白类药物载体，具有重要的学术价值和应用前景。

β-葡聚糖是一类重要的天然高分子，不仅具有较好的生物活性，如调节机体免疫能力和抗肿瘤活性等优点，而且具有较好的生物相容性，可作为基因或者药物分子的优良载体。本项目建立了调控酵母 β-葡聚糖颗粒空腔尺寸大小的具体制备参数，通过改变酵母颗粒的封闭材料，研究了其负载蛋白分子在人工胃酸环境中的缓释行为；基于三螺旋β-葡聚糖变性-复性的特性，通过β-葡聚糖/β-环糊精主客体作用构建了一种新型的载药胶束，考察了其在体内外的缓释行为，揭示了该胶束作为药物载体的潜在应用前景；探讨了三螺旋β-葡聚糖/金纳米粒子复合物的细胞毒性、抗肿瘤活性及作用机制，揭示了其主要依赖刺激癌细胞产生ROS，导致线粒体的过氧化损伤，进一步激活凋亡蛋白酶caspase-9，最终导致肿瘤细胞的凋亡的作用机制；从紫苏籽饼粕中提取、分离纯化获得了紫苏寡肽，研究了其氨基酸序列结构以及抑制癌细胞增长的效用。此外，基于低温强碱溶液体系，构建了多种功能性壳聚糖凝胶材料，如电场响应凝胶驱动器、剪切变稀凝胶、高强度各项异性凝胶材料以及自愈合、自粘附凝胶敷料等。本项目为探索天然多糖在生物体内的重要作用以及开拓它在生物医药与材料领域的应用提供了科学依据，具有重要的学术价值和应用价值。