Schatz Christophe, Lecommandoux Sébastien
Université de Bordeaux, UMR5629, ENSCBP, 16, Avenue Pey Berland, 33607 Pessac Cedex, France; CNRS, Laboratoire de Chimie des Polymères Organiques, UMR5629, Pessac, France.
Macromol Rapid Commun. 2010 Oct 1;31(19):1664-84. doi: 10.1002/marc.201000267. Epub 2010 Aug 26.
While polysaccharide graft copolymers and glycopolymers have been widely studied and used in various applications, linear block copolymer structures combining a polysaccharide segment and a synthetic one have been less described. The limited availability of the polysaccharide reducing-end, the difficulty of finding a common solvent of both blocks and the need sometimes to protect the lateral hydroxyl groups of the polysaccharide chain may explain the relatively low number of studies on this copolymer family despite its potential interest. Polysaccharide block copolymers feature physicochemical properties not only close to those of synthetic block copolymers but also bring an added value such as the biodegradability, the biocompatibility or the bioactivity in some cases. This review aims at presenting the synthetic pathways towards such structures, from the basic polymerization techniques to the most recent ones including controlled/living polymerization mechanisms and also by emphasizing the chemical reactions used to functionalize the reducing-end of the polysaccharide block. The amphiphilic nature of most of the polysaccharide-based block copolymers reported so far gives rise to various self-assembly morphologies in the solid state or in selective solvents. In addition, the rigidity of the polysaccharide block is expected to influence the microphase separation of the block copolymer by increasing the thermodynamic incompatibility between dissimilar blocks. A special interest was drawn to the formation and the properties of polymer vesicles (polymersomes) in aqueous solutions. Polysaccharide block copolymers might represent a new class of biomaterials with potential applications in different fields such as the plastic industry, the detergency and also the pharmaceutics where the design of nanodevices carrying a native polysaccharide chain is of interest for therapy, vaccination and diagnosis purposes.
虽然多糖接枝共聚物和糖聚合物已被广泛研究并应用于各种领域，但结合多糖链段和合成链段的线性嵌段共聚物结构的描述却较少。多糖还原端的可用性有限、难以找到两个链段的共同溶剂以及有时需要保护多糖链的侧羟基，这些因素可能解释了尽管该共聚物家族具有潜在的研究价值，但相关研究数量相对较少的原因。多糖嵌段共聚物不仅具有与合成嵌段共聚物相近的物理化学性质，而且在某些情况下还具有生物可降解性、生物相容性或生物活性等附加价值。本综述旨在介绍合成此类结构的方法，从基本的聚合技术到包括可控/活性聚合机制在内的最新技术，并着重强调用于官能化多糖嵌段还原端的化学反应。到目前为止报道的大多数基于多糖的嵌段共聚物的两亲性在固态或选择性溶剂中会产生各种自组装形态。此外，多糖链段的刚性预计会通过增加不同链段之间的热力学不相容性来影响嵌段共聚物的微相分离。人们对聚合物囊泡（聚合物osomes）在水溶液中的形成和性质特别感兴趣。多糖嵌段共聚物可能代表一类新型生物材料，在塑料工业、洗涤剂以及制药等不同领域具有潜在应用，其中携带天然多糖链的纳米器件的设计对于治疗、疫苗接种和诊断目的具有重要意义。
