Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Korea.
Organic Materials and Fiber Engineering, Jeonbuk National University, 567 Baekje-daero, Deogjin-dong, Deokjin-gu, Jeonju, Jeollabuk-do 54896, Korea.
ACS Appl Mater Interfaces. 2020 Dec 9;12(49):55467-55475. doi: 10.1021/acsami.0c16968. Epub 2020 Nov 25.
Aqueous two-phase systems (ATPSs) have been widely used in the separation, purification, and enrichment of biomolecules for their excellent biocompatibility. While ultracentrifugation and microfluidic devices have been combined with ATPS to facilitate the separation of biomolecules and achieve high recovery yields, they often lack the ability to effectively isolate and separate biomolecules in low concentrations. In this work, we present a strategy that leverages the preferential partitioning of biomolecules in ATPS droplets to efficiently separate model extracellular vesicle (EV) particles. We demonstrate that the additional oil phase between the inner ATPS droplets and the aqueous continuous phase in triple emulsion droplets resolves the size controllability and instability issues of ATPS droplets, enabling the production of highly monodisperse ATPS-based polymersomes with enhanced stability for effective isolation of ATPS droplets from the surrounding environment. Furthermore, we achieve separation of model EV particles in a single dextran (DEX)-rich droplet by the massive production of ATPS-based polymersomes and osmotic-pressure-induced rupture of the selected polymersome in a hypertonic solution composed of poly(ethylene glycol) (PEG).
双水相系统（ATPS）因其出色的生物相容性而被广泛应用于生物分子的分离、纯化和富集。虽然超速离心和微流控设备已经与 ATPS 结合，以促进生物分子的分离并实现高回收率，但它们往往缺乏有效分离低浓度生物分子的能力。在这项工作中，我们提出了一种策略，利用生物分子在 ATPS 液滴中的优先分配来有效地分离模型细胞外囊泡（EV）颗粒。我们证明，在三重乳液液滴中，内 ATPS 液滴与水连续相之间的额外油相解决了 ATPS 液滴的尺寸可控性和不稳定性问题，从而能够生产出具有增强稳定性的高度单分散 ATPS 聚合物囊泡，有效地将 ATPS 液滴与周围环境隔离开来。此外，我们通过大量生产基于 ATPS 的聚合物囊泡，并在由聚乙二醇（PEG）组成的高渗溶液中通过渗透压诱导选择的聚合物囊泡破裂，实现了模型 EV 颗粒在单个葡聚糖（DEX）丰富液滴中的分离。
