Polymeric micelles are representative self-assembly structures of block copolymers and have widely been investigated from both fundamental and applied aspects. In 1995, we discovered polyion complex (PIC) micelles formed from a pair of oppositely charged block copolymers with poly(ethylene glycol) segments through electrostatic interactions in aqueous media, which expanded the concept of polymeric micelle formation in selective solvents. Hereafter, extensive studies have been carried out on PIC micelles, for example, fundamental characterizations as a novel class of self-assembly systems and applications as nanocarrier systems for the delivery of charged molecules with therapeutic efficacies, including nucleic acids and proteins. This review mainly focuses on physicochemical studies on the formation of PIC micelles, particularly the critical molecular factors that have a role to determine the self-assembly scheme of charged block copolymers for micelle structures. This review focuses on the physicochemical characterization of polyion complex (PIC) micelles, particularly addressing the critical molecular factors to determine the self-assembly scheme of double-hydrophilic block copolymers composed of charged and non-charged segments into micelle structures. The process of PIC micelle formation provides new insights on the block copolymer self-assembly in thermodynamically equilibrium condition in aqueous medium, such as chain length recognition and transition from uPIC, which is the PIC of smallest neutralizing unit, to PIC micelle structures.

中文翻译：

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在水性介质中由带电和不带电链段组成的双亲水嵌段共聚物形成聚离子复合胶束

聚合物胶束是嵌段共聚物的代表性自组装结构，已从基础和应用两个方面进行了广泛的研究。1995 年，我们发现了聚离子复合物 (PIC) 胶束，该胶束由一对带相反电荷的嵌段共聚物与聚乙二醇链段通过水介质中的静电相互作用形成，这扩展了在选择性溶剂中形成聚合物胶束的概念。此后，对 PIC 胶束进行了广泛的研究，例如，作为一类新型自组装系统的基本特征和作为纳米载体系统的应用，用于递送具有治疗功效的带电分子，包括核酸和蛋白质。本综述主要集中在 PIC 胶束形成的物理化学研究，特别是决定胶束结构带电嵌段共聚物自组装方案的关键分子因素。本综述侧重于聚离子复合物 (PIC) 胶束的物理化学表征，特别是解决确定由带电和不带电链段组成的双亲水嵌段共聚物自组装成胶束结构的关键分子因素。PIC 胶束的形成过程为水性介质中热力学平衡条件下的嵌段共聚物自组装提供了新的见解，例如链长识别和从 uPIC（最小中和单元的 PIC）到 PIC 胶束结构的转变。本综述侧重于聚离子复合物 (PIC) 胶束的物理化学表征，特别是解决确定由带电和不带电链段组成的双亲水嵌段共聚物自组装成胶束结构的关键分子因素。PIC 胶束的形成过程为水性介质中热力学平衡条件下的嵌段共聚物自组装提供了新的见解，例如链长识别和从 uPIC（最小中和单元的 PIC）到 PIC 胶束结构的转变。本综述侧重于聚离子复合物 (PIC) 胶束的物理化学表征，特别是解决确定由带电和不带电链段组成的双亲水嵌段共聚物自组装成胶束结构的关键分子因素。PIC 胶束的形成过程为水性介质中热力学平衡条件下的嵌段共聚物自组装提供了新的见解，例如链长识别和从 uPIC（最小中和单元的 PIC）到 PIC 胶束结构的转变。特别是解决关键分子因素，以确定由带电和不带电链段组成的胶束结构的双亲水嵌段共聚物的自组装方案。PIC 胶束的形成过程为水性介质中热力学平衡条件下的嵌段共聚物自组装提供了新的见解，例如链长识别和从 uPIC（最小中和单元的 PIC）到 PIC 胶束结构的转变。特别是解决关键分子因素，以确定由带电和不带电链段组成的胶束结构的双亲水嵌段共聚物的自组装方案。PIC 胶束的形成过程为水性介质中热力学平衡条件下的嵌段共聚物自组装提供了新的见解，例如链长识别和从 uPIC（最小中和单元的 PIC）到 PIC 胶束结构的转变。