Microfluidic Preparation of Hydrogel Microcapsules Using Aqueous Two-Phase System Formation in Monodisperse Droplets

We propose a microfluidic process to prepare monodisperse microcapsules possessing a large aqueous core and a hydrogel membrane shell through the formation of aqueous two-phase system droplets with dextran-rich core and tetra-PEG-rich shell and subsequent cross-linking reaction in the shell. This microfluidic approach can continuously produce the microcapsules from water-in-oil emulsion droplets under mild conditions without the use of radical initiators and external energy such as heat and ultraviolet light. In addition, the size and thickness of the microcapsules can be controlled separately by changing flow conditions upon microfluidic emulsification. In this paper, authors will introduce the detailed preparation procedure of the microcapsules.