STRUCTURE FUNCTION RELATIONSHIPS IN POLYSACCHARIDES AND POLYSACCHARIDE-BLENDS

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其他NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， NCRR赠款不直接向子项目或子项目工作人员提供资金。 多糖是一类独特的生物聚合物。它们构成海洋甲壳类动物、植物、藻类和微生物壁的主要结构成分。它们具有广泛的不同化学结构，并表现出各种独特的分子结构，导致单、双和三螺旋的片和螺旋。它们构成了可再生资源的大量来源，为人类提供了各种各样的有益功能，特别是在用于组织工程药物载体的生物材料和营养药物的受控释放领域，仅举几例。特别是它们的特殊性质，如可再生性、生物降解性和生物活性，促进了新应用的发展。这些多糖中的许多是水溶性的，并且能够显著改变水基溶液的流变学，例如质地增稠、胶凝粘度、乳化、水合和食品分散体的物理稳定性，并且发现食品、化妆品、生物医学和制药应用的范围。在这方面，对多糖结构的结构多样性和基本知识的详细理解，以及对其形状和原子水平相互作用的见解，有助于理解和预测主要与其最终用途应用相关的功能。目前的建议是关于确定一些生物学上重要的和工业上有用的多糖和多糖共混物的分子结构及其与溶剂和溶质分子的相互作用。该研究包括多糖如I-角叉菜胶、κ-角叉菜胶、λ-角叉菜胶、洋葱半乳葡甘露聚糖、玉米阿拉伯木聚糖和欧车前，以及二元体系如丙酮：葡甘露聚糖黄原胶：葡甘露聚糖黄原胶：半乳甘露聚糖、玉米阿拉伯木聚糖：半乳甘露聚糖I-角叉菜胶：半乳甘露聚糖和κ-角叉菜胶-半乳甘露聚糖。此外，我们最近的研究表明，几种药物分子，营养品或维生素可以嵌入到结晶的I-角叉菜胶网络中，导致新的聚合物共晶。与显示凝胶化行为的I-角叉菜胶相比，这些材料高度溶于水。此外，热性质表明，被截留的分子受到角叉菜胶分子的保护，免受外部扰动，这些复合物具有作为控制递送载体的潜力。为了获得关于小分子与多糖骨架之间的内在相互作用的知识，以便理解这些小分子从多糖基质中的释放曲线，我们的第二个目标集中在利用FDA批准的食品多糖与小药物分子以及营养品组合的几种聚合物共晶的结构表征上。我们坚信，从这项拟议的研究中获得的结构结果将有助于了解多糖：药物相互作用对基于多糖的药物控释载体的发展。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Polysaccharides comprise a distinct class of biopolymers. They form major structural components of the walls of marine crustaceans plants algae and microorganisms. They have extensive group of different chemical structures and exhibit a wide variety of unique molecular structures leading to sheets and spirals of single double and triple helices. They constitute a large source of renewable resources offering a wide variety of beneficial functionalities to mankind especially in the domain of biomaterials for tissue engineering drug vehicles and controlled release of nutraceuticals to name a few. In particular their special properties such as renewability biodegrability and biological activity spawn the development of novel applications. Many of these polysaccharides are water soluble and are capable of significantly altering the rheology of aqueous based solutions such as texture thickening gelling viscosity emulsifying hydrating and physical stability of food dispersions and find a gamut of food cosmetic biomedical and pharmaceutical applications. In this regard a detailed understanding about the structural diversity and fundamental knowledge of polysaccharides architecture with insights about their shape and atomic level interactions aids in understanding and predicting the functionality which is mainly related to their end-use applications. The current proposal is about determining the molecular architecture of a number of biologically important and industrially useful polysaccharides and polysaccharide-blends and their interactions with solvent and solute molecules. The study includes polysaccharides such as iota-carrageenan kappa-carrageenan lambda carrageenan; cepacian galactoglucomannan corn arabinoxylan and psyllium and binary systems such as acetan:glucomannan xanthan:glucomannan xanthan:galactomanna corn arabinoxylan:galactomannan iota-carrageenan:galactomannan and kappa-carrageenan-galactomannan. Further our recent research demonstrates that several drug molecules nutraceuticals or vitamins can be embedded in the crystalline iota-carrageenan network leading to novel polymeric cocrystals. These materials are highly soluble in water compared to iota-carrageenan that displays gelation behavior. Further the thermal properties suggest that the entrapped molecules are protected from external perturbations by the carrageenan molecules and these complexes have the potential to server as control delivery vehicles. In order to gain knowledge about the intrinsic interactions between the small molecules with the polysaccharide backbone so as to understanding the release profile of these small molecules from the polysaccharide matrix our second aim is centered on structural characterization of several polymeric cocrystals utilizing FDA approved food polysaccharides combined with small drug molecules as well as nutraceuticals. We strongly believe that the structural results obtained from this proposed study would be helpful in understanding the polysaccharide:drug interactions towards the development of polysaccharide based controlled drug releasing carriers.