Controlled release of multiple actives after encapsulation in a microenvironment is significant for various biological and chemical applications such as controlled drug delivery and transplantation of encapsulated cells. However, traditional systems often lack efficient encapsulation and release of multiple actives, especially when incorporated substances must be released at a targeted location. Here, we present a straightforward approach to release multiple actives at a prescribed position in microfluidic systems; one or two actives are encapsulated in water-in-oil-in-water emulsion droplets, followed by controlled release of the actives via an alternating current electric field. An electric field-induced compression due to Maxwell–Wagner interfacial polarization overcomes the disjoining pressure at the thin shell and leads to the thinning and rupture of the oil layer of the droplets, resulting in the release of the encapsulated actives to the suspending medium. This technique is feasible for encapsulation and release of various reagents in terms of ion species and ion concentrations. Moreover, polymer nanoparticles and yeast cells can also be included in the droplets and then be released at targeted locations. This versatile method should be well-suited for targeted delivery of various active ingredients such as functional chemical reagents and biological cells.

中文翻译：

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电控快速释放包裹在双乳液液滴中的活性物质†

包封在微环境中后多种活性物质的受控释放对于各种生物学和化学应用（例如受控的药物递送和包封的细胞的移植）具有重要意义。但是，传统系统通常缺乏有效活性成分的有效包封和释放，尤其是当必须在目标位置释放掺入的物质时。在这里，我们提出了一种直接的方法来释放微流体系统中指定位置的多种活性物质。将一种或两种活性物质封装在水包油包水型乳剂液滴中，然后通过交流电场。麦克斯韦-瓦格纳（Maxwell-Wagner）界面极化引起的电场压缩克服了薄壳处的分离压力，并导致液滴的油层变薄和破裂，从而导致封装的活性物质释放到悬浮介质中。就离子种类和离子浓度而言，该技术对于各种试剂的封装和释放是可行的。此外，聚合物纳米颗粒和酵母细胞也可以包含在液滴中，然后在目标位置释放。这种通用的方法应该非常适合于有针对性地输送各种活性成分，例如功能化学试剂和生物细胞。