Soft Materials Laboratory, Institute of Materials, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.
Institute of Bioengineering and Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015, Switzerland.
ACS Appl Mater Interfaces. 2021 Apr 7;13(13):15601-15609. doi: 10.1021/acsami.1c00230. Epub 2021 Mar 25.
Capsules are often used to protect chemical and biological entities from the environment, to control the timing and location of their release, or to facilitate the collection of waste. Their performance depends on the thickness and composition of their shells, which can be closely controlled if capsules are made from double emulsion drops that are produced with microfluidics. However, the fabrication of such double emulsions is delicate, limiting throughput and increasing costs. Here, a fast, scalable method to produce monodisperse microcapsules possessing mechanically robust, thin, semipermeable hydrogel shells from single emulsion drops is introduced. This is achieved by selectively polymerizing reagents in close proximity to the drop surface to form a biocompatible 1.6 μm-thick hydrogel shell that encompasses a liquid core. The size-selective permeability of the shell enables the growth of living yeast and bacteria in their cores. Moreover, if capsules are loaded with adsorbents, they can repetitively remove waste products from water. The simplicity and robustness of the capsule fabrication makes the process scalable and cost effective. It has thus the potential to extend the use of calibrated capsules possessing well-defined dimensions to cost sensitive fields, including food, waste water treatment, or oil recovery.
胶囊通常用于保护化学和生物实体免受环境影响，控制其释放的时间和位置，或方便废物的收集。其性能取决于其外壳的厚度和组成，如果胶囊是由微流控技术制备的双乳液滴制成的，则可以对其进行精确控制。然而，这种双乳液的制备过程非常精细，限制了产量并增加了成本。在这里，我们介绍了一种快速、可扩展的方法，可从单乳液滴中生产出具有机械强度高、薄、半渗透水凝胶外壳的单分散微胶囊。通过选择性地在靠近液滴表面的位置聚合试剂来实现这一点，从而形成一层 1.6 微米厚的生物相容性水凝胶外壳，包围着一个液体核心。外壳的尺寸选择性渗透性允许活酵母和细菌在其核心中生长。此外，如果胶囊中装载有吸附剂，则可以从水中重复去除废物。胶囊制造的简单性和鲁棒性使该过程具有可扩展性和成本效益。因此，它有可能将具有明确定义尺寸的校准胶囊的使用扩展到包括食品、废水处理或采油等对成本敏感的领域。
