Understanding the formation of highly ordered structures through self-assembly is crucial for developing various biologically relevant systems. A significant expansion in the development of self-assembly chemistry features stable coassembly formation using a mixture of two oppositely charged polymers. This study provides insightful findings on the coassembly of hydrophobic coumarin-integrated cationic (P1–P3) and anionic (P1′–P3′) copolymers toward the formation of vesicles in aqueous medium at pH 7.4, with a hydrodynamic diameter (D_h) of 160 ± 10 nm and electrically neutral zwitterionic surfaces, confirmed by dynamic light scattering. Upon varying the solution pH, an intriguing charge switchable behavior (+ve → 0 → −ve) and a drastic morphological transition to spherical aggregates of the vesicles were noticed. At pH 7.4, these coassembled vesicles possess a neutral surface charge, empowering them to resist nonspecific protein (pepsin and lysozyme) adsorption via electrostatic repulsion, as evidenced by size evolution and protein binding measurements. Additionally, the bilayer membrane allows for the encapsulation of hydrophilic and hydrophobic guest molecules and their sustained release in the presence of 10 mM esterase; thus, this study demonstrates potential applications of coassembly to serve as a drug delivery vehicle.

中文翻译：

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带电共聚物两亲物的共组装，具有 pH 调节的防污性能


了解通过自组装形成高度有序的结构对于开发各种生物学相关系统至关重要。自组装化学发展的重大扩展的特点是使用两种带相反电荷的聚合物的混合物稳定地形成共组装。本研究为疏水性香豆素集成阳离子 （P1–P3） 和阴离子 （P1′–P3′） 共聚物在 pH 7.4 的水性介质中形成囊泡提供了深刻的发现，其流体动力学直径 （D_h） 为 160 ± 10 nm，电中性两性离子表面，动态光散射证实了这一点。在改变溶液 pH 值时，注意到一种有趣的电荷可切换行为 （+ve → 0 → −ve） 和向囊泡球形聚集体的剧烈形态转变。在 pH 值为 7.4 时，这些共组装的囊泡具有中性表面电荷，使它们能够通过静电排斥抵抗非特异性蛋白质（胃蛋白酶和溶菌酶）吸附，大小演变和蛋白质结合测量证明了这一点。此外，双层膜允许封装亲水性和疏水性客体分子，并在 10 mM 酯酶存在下持续释放;因此，本研究展示了共组装作为药物递送载体的潜在应用。