Abstract Triblock copolymers display, in water, a rich phase behavior with changes in temperature and concentration that makes them particularly attractive for many industrial and biomedical applications. In an attempt to develop smart carriers with improved properties, additives such as polysaccharides are often included in the poloxamer formulations. In the present work, we examine and compare the associative properties of concentrated aqueous solutions of pluronic F127 in presence of chitosan and guar gum. Dynamic light scattering was used to analyze the effects of the two polysaccharides on the different self-assembled structures formed within these solutions as a function of temperature from the micellization to the sol-gel transition. The most marked differences between the two systems can be observed above the sol-gel transition, where the analysis of the correlation functions evidenced the presence of three processes: a fast process that represents unimers diffusion, an intermediate process related to individual hydrated micelles, and a slow mode due to the presence of large micellar aggregates. We hypothesize that the different molecular weight and ionic character of the polysaccharides are responsible for the different size of the diffusing entities as well for the nature of the bonds which hold together the extended network between micelles formed above the sol-gel transition.

中文翻译：

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普朗尼克-壳聚糖与普朗尼克-瓜尔胶复合热凝胶的对比研究

摘要 三嵌段共聚物在水中表现出随着温度和浓度变化而变化的丰富相行为，这使得它们对许多工业和生物医学应用特别有吸引力。为了开发具有改进性能的智能载体，泊洛沙姆制剂中通常包含添加剂，例如多糖。在目前的工作中，我们检查并比较了在壳聚糖和瓜尔豆胶存在下 pluronic F127 的浓缩水溶液的缔合特性。动态光散射用于分析两种多糖对这些溶液中形成的不同自组装结构的影响，作为从胶束化到溶胶-凝胶转变的温度的函数。在溶胶-凝胶转变上方可以观察到两个系统之间最显着的差异，其中相关函数的分析证明存在三个过程：代表单聚体扩散的快速过程，与单个水合胶束相关的中间过程，以及由于存在大胶束聚集体而导致的慢速模式。我们假设多糖的不同分子量和离子特性是造成不同大小的扩散实体以及将在溶胶-凝胶转变上方形成的胶束之间的扩展网络结合在一起的键的性质的原因。