Self-assembling Polysaccharide Polyelectrolytes

我们的目标是了解多糖系统中的电荷调节如何影响自组装，并利用这一知识创建模拟自然的纳米结构系统，并扩大多糖在药物输送、伤口治疗和组织工程领域的应用领域。该项目将结合多糖合成和修饰、纤维素纳米晶制备和表征以及表面修饰和表征方面的专业知识。德国部分是从不同来源的木聚糖和其他半纤维素中设计出水溶性/可分散的多糖，以柯德兰和普鲁兰为模型化合物，通过逐层组装的方式，以离子取代基和疏水的肉桂酰基或肉桂酰光交联基形成薄膜结构。为此，通过控制取代度(DS)和电荷密度，以及应用溶解或溶胀聚合物与合成多糖聚电解质衍生物的重复单元内和聚合物链上官能团的分布，寻求合成多糖阳离子衍生物(羟丙基三甲基铵、二烷基氨甲基衍生物)和阴离子衍生物(羧甲基或硫酸半酯衍生物)以及肉桂酰酯和肉桂基醚的新途径。通过一维和二维核磁共振、扫描电子显微镜和高效液相色谱等手段对酸链或酶链降解后的多糖聚电解质进行了表征，获得了较为全面的结构信息。

Our goal is to understand how charge regulation in polysaccharide systems affects self-assembly and to use this knowledge to create nanostructured systems that mimic nature and expand the application domain of polysaccharides in fields of drug delivery, wound treatment, and tissue engineering. The project will combine expertise in polysaccharide synthesis and modification, cellulose nanocrystal preparation and characterization, and surface modification and characterization. The German part is the design of water soluble/disperable polysaccharides from xylan and other hemicelluloses from different sources, and curdlan and pullulan as model compound, with ionic substituents and hydrophobic cinnamoyl or cinnamyl photocrosslinking groups for thin film formation structures through layer-by-layer assembly. For this purpose, novel synthesis paths to polysaccharide cationic derivatives (hydroxypropyltrimethylammonium, dialkylammoniumethyl derivatives) and anionic ones (carboxymethyl or sulfur acid half ester derivatives) and cinnamoyl esters and cinnamyl ethers are aspired by control of the degree of substitution (DS) and hence charge density, and the distribution of the functions within the repeating unit and along the polymer chain applying dissolved or swollen polymers vs. conventional paths for synthesis of polysaccharide polyelectrolyte derivatives. The polysaccharide polyelectrolytes are characterized by means of one- and two dimensional NMR, SEC, and HPLC techniques after acidic or enzymatic chain degradation to get a comprehensive structure information.