Direct formation of giant unilamellar vesicles from microparticles of polyion complexes and investigation of their properties using a microfluidic chamber
Direct formation of giant unilamellar vesicles from microparticles of polyion complexes and investigation of their properties using a microfluidic chamber
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DOI：
10.1039/c3sm00089c
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发表时间：
2013-01-01
期刊：
影响因子：
3.4
通讯作者：
Washizu, Masao
中科院分区：
文献类型：
--
作者：
Oana, Hidehiro;Morinaga, Mutsuki;Washizu, Masao
尽管中空微型胶囊具有多种潜在的生物医学应用，但无有机溶剂制备方法的报道相当有限。在此，利用聚离子络合物（PIC）对添加盐浓度变化的独特响应，展示了一种无有机溶剂制备巨型单层囊泡的新方法。微流体装置由主通道轴承侧袋组成，可用作微型反应室，旨在促进光学显微镜下的制备过程。利用该装置，可以实时观察在添加剂盐浓度快速降低的过程中单个PIC微粒的形态转变以及PIC微粒直接形成巨型囊泡。形成的囊泡的表面积和PIC微粒的体积之间存在拟线性关系，并且通过该关系估计的囊泡膜的厚度表明PIC膜形成了均匀的单层结构。此外，使用微流体室研究了所形成的 PIC 囊泡的详细特性，包括盐响应、客体分子的负载以及通过交联对 PIC 膜进行修饰或未修饰的 PIC 膜的渗透性。因此，还证明了微流体室在周围条件变化期间微尺度软材料动态响应的可视化和研究方面的有用性。
Although hollow microscopic capsules have a variety of potential biomedical applications, reports of organic-solvent-free methods for their preparation are rather limited. Herein, a novel approach is demonstrated for organic-solvent-free preparation of giant unilamellar vesicles utilizing the unique response of polyion complexes (PICs) to changes in additive salt concentration. A microfluidic device consisting of a main channel bearing side pockets that work as microscale reaction chambers is designed for facilitating the preparation process under an optical microscope. With this device, real-time observation of morphological transformation of individual PIC microparticles is carried out during rapid reduction of the additive salt concentration and direct formation of giant vesicles from PIC microparticles is shown. There is a quasilinear relationship between the surface areas of the formed vesicles and the volumes of the PIC microparticles, and the thickness of the vesicle membrane estimated by the relationship is indicative of the formation of a uniform unilamellar structure of the PIC membrane. Furthermore, detailed properties of the formed PIC vesicles with regard to salt response, loading of guest molecules, and permeability of the PIC membrane with/without modification of the PIC membrane by cross-linking are investigated using the microfluidic chamber. Thus, the usefulness of the microfluidic chamber for visualization and investigation of dynamic responses of microscale soft materials during changes in surrounding conditions is also demonstrated.