Hann Sarah D, Lee Daeyeon, Stebe Kathleen J
Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, USA.
Phys Chem Chem Phys. 2017 Sep 13;19(35):23825-23831. doi: 10.1039/c7cp02809a.
Interfacial complexation between two oppositely charged polymers in aqueous two phase systems (ATPSs) leads to the formation of mechanically robust microcapsules that can be stressed without losing their structural integrity. When a polyelectrolyte (PE) is replaced with a charged nanoparticle (NP), microcapsules with internal compartments can be generated within an encapsulated shell comprising NPs and PEs, named AWE-somes. These shells, made by interfacial complexation between PEs and NPs, are, however, very brittle and can lose their integrity under mechanical stress, potentially limiting their applications. Improved control over the properties and structure of microcapsules over a wide range is needed to enable their broad utilization. In this work, we show that interfacial complexation of a polycation with a mixture of a polyanion and a negatively charged NP in ATPS presents a simple yet versatile method of tuning the structure and properties of microcapsules. We show that internal structure, along with the mechanical robustness and stimuli-responsive properties of microcapsules, can be varied by changing the concentrations of polyanion and NP present in one of the two aqueous phases. Interfacial complexation of PE with mixtures of PE and NP provides a new strategy for controlling and imparting the properties and functionality of AWE-some interfacial membranes for applications in encapsulation and release of active agents and recapitulation of basic functions of living cells.
在双水相体系（ATPSs）中，两种带相反电荷的聚合物之间的界面络合作用会导致形成机械性能稳定的微胶囊，这种微胶囊在受力时不会失去其结构完整性。当用带电纳米颗粒（NP）取代聚电解质（PE）时，可以在由NP和PE组成的包封壳内生成具有内部隔室的微胶囊，即AWE-somes。然而，这些通过PE和NP之间的界面络合作用形成的壳非常脆，在机械应力下可能会失去完整性，这可能会限制它们的应用。需要在很宽的范围内对微胶囊的性质和结构进行更好的控制，以实现它们的广泛应用。在这项工作中，我们表明在ATPS中，聚阳离子与聚阴离子和带负电荷的NP的混合物之间的界面络合提供了一种简单而通用的方法来调节微胶囊的结构和性质。我们表明，通过改变两个水相之一中聚阴离子和NP的浓度，可以改变微胶囊的内部结构以及其机械稳定性和刺激响应特性。PE与PE和NP的混合物之间的界面络合为控制和赋予AWE-some界面膜的性质和功能提供了一种新策略，可用于活性剂的封装和释放以及模拟活细胞的基本功能。
