基于聚乳酸两亲性共聚物的立构复合胶束与物理凝胶的研究进展

Stereocomplexed Micelles and Physical Gels Formed from Poly( Lactic Acid) Amphiphilic Copolymers: A Review

两亲性共聚物在水溶液中可形成胶束、物理凝胶等多层次自组装结构,疏水链段的结晶和立构复合是影响其胶束、物理凝胶形成的过程、结构与性能的重要因素。聚乳酸(PLA)是一种典型的生物基/生物可降解高分子,其2种对映体聚左旋乳酸(PLLA)与聚右旋乳酸(PDLA)之间可形成立构复合结晶。由于立构复合结晶中较强的链间相互作用,含PLLA和PDLA疏水链段的两亲性共聚物水溶液混合后,可形成立构复合胶束与物理凝胶,这为生物可降解、生物相容的胶束与物理凝胶材料的制备与性能调控提供了一种新方法,近年来该领域备受关注。文中介绍了基于PLA两亲性共聚物的立构复合胶束与物理凝胶的制备和性能,并从聚合物链拓扑结构设计出发,详细综述了近年来PLA立构复合胶束与物理凝胶的研究进展,以及聚合物相对分子质量、浓度、共聚组成、温度等因素对立构复合胶束和凝胶结构与性能的影响。

Amphiphilic copolymers can form hierarchical self-assembled structures such as micelles and physical gels in aqueous solution. Crystallization and stereocomplexation of hydrophobic segment in amphiphilic copolymers are key factors influencing the formation process,structure,and properties of their micelles and physical gels. Poly（ lactic acid）is a typical biobased and biodegradable polymers and their two stereoisomers,i. e.,poly（ L-lactic acid）（ PLLA） and poly（ D-lactic acid）（ PDLA）,can form stereocomplexation. Because of intermolecular interactions in PLLA / PDLA stereocomplex crystallites,the amphiphilic copolymers containing PLLA and PDLA hydrophobic segments can form stereocomplexed micelles and physical gels upon mixing in aqueous solution. This provides a new method to prepare and control properties of copolymer micelles and physical gels with good biodegradability and biocompatibility. This area has drawn great attentions in recent years. In this paper,the preparation and properties of stereocomplexed micelles and physical gels formed from PLA amphiphilic copolymers were introduced. Research progresses of stereocomplexed micelles and physical gels containing PLA segments,as well as effects of copolymer topology,molecular weight,concentration,composition,and temperature on the structure and properties of stereocomplexed micelles and gels were systematically reviewed.