Polyelectrolyte complex based micelles have attracted significant attention due to their potential regarding bio-applications. Although the morphology and functions have been studied extensively, dynamic properties, particularly component exchange with other surrounding molecules, have remained elusive to date. Here, we show how micelles based on metal–ligand coordination complex coacervate-core micelles (M-C3Ms) respond to addition of extra ligand and metal ions. The micelles are prepared from a polycationic-neutral diblock copolymer and an anionic coordination polyelectrolyte, which is obtained by coordination between metal ions (lanthanides Ln³⁺ and Zn²⁺) and a bis-ligand (LEO) containing two dipicolinic acid (DPA) groups connected by a tetra-ethylene oxide spacer (4EO). Our findings show that the bis-ligand LEO is essential for the growth of coordination polymers and consequently the formation of micelles, leading to equilibrium structures with the same micellar composition and structure independent of the order of mixing. In other words, adding single DPA has no effect on the formed M-C3Ms. As for metal exchange, we find that added Zn²⁺ can replace some of the Ln³⁺ from Ln-C3Ms, leading to a hybrid coordination structure with both Ln³⁺ and Zn²⁺. We find that component exchange occurs in these coordination polyelectrolyte micelles, but it is more favorable in the direction of replacing the weak binding components with strong ones. Hence, the designed M-C3Ms based on the strong binding components, such as Ln-C3Ms, shall be relatively stable in biological surroundings, paving the way for the application of such particles as bio-imaging probes.

中文翻译：

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基于金属配位的聚电解质复合胶束对添加的配体和金属的响应

基于聚电解质复合物的胶束由于其在生物应用方面的潜力而备受关注。尽管对形态和功能进行了广泛的研究，但迄今为止，动力学特性，尤其是与周围其他分子的组分交换仍然难以捉摸。在这里，我们展示了基于金属-配体配合物凝聚层-核心胶束（M-C3Ms）的胶束如何响应额外配体和金属离子的添加​​。胶束由聚阳离子-中性二嵌段共聚物和阴离子配位聚电解质制备而成，阴离子配位聚电解质是通过金属离子（镧系元素Ln ³⁺和Zn ²⁺）和含有两个通过四环氧乙烷间隔基（4EO）连接的二吡啶甲酸（DPA）基团的双配体（LEO）。我们的发现表明，双配体LEO对于配位聚合物的生长以及由此形成的胶束至关重要，从而导致具有相同胶束组成的平衡结构和独立于混合顺序的结构。换句话说，添加单个DPA对形成的M-C3M没有影响。对于金属交换，我们发现添加的Zn ²⁺可以替代Ln-C3Ms中的某些Ln ³⁺，从而导致Ln ³⁺和Zn ²⁺均具有混合配位结构。。我们发现，在这些配位聚电解质胶束中发生组分交换，但是在用强组分取代弱结合组分的方向上更有利。因此，基于强结合成分（例如Ln-C3Ms）设计的M-C3Ms在生物环境中应相对稳定，从而为诸如生物成像探针之类的颗粒的应用铺平了道路。