Kim Minji, Jeon Kyounghee, Hee Kim Won, Wook Lee Jeong, Hwang Yoon-Ho, Lee Hyomin
Soft Matter and Functional Interfaces Laboratory, Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, South Korea.
School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), Pohang, South Korea.
J Colloid Interface Sci. 2022 Jun 15;616:488-498. doi: 10.1016/j.jcis.2022.02.077. Epub 2022 Feb 19.
Emulsions in which water droplets are dispersed in fluorocarbon oil phase (W/F emulsions) serve as effective means to encapsulate bioactives and precisely execute reactions in confined space due to the gas permeability, chemical inertness, and biocompatibility offered by the continuous phase. While molecular surfactants consisting of perfluorinated polyether (PFPE) and polyethylene glycol (PEG) have been used to stabilize these emulsions, these surfactants cannot effectively prevent coalescence and cross-contamination between the neighboring droplets. Herein, we present Janus nanoparticles (F-SiO-PEG) as biocompatible colloidal surfactants to achieve excellent stability in W/F emulsions. By utilizing monolayered wax colloidosomes as templates, we show that Janus silica nanoparticles with two distinctive surface wetting properties can be synthesized in high purity. Moreover, we demonstrate that additional PEGylation of these Janus particles allows these colloidal surfactants to strongly adhere at the W/F interface, granting excellent emulsion stability compared to the equivalent randomly functionalized nanoparticles and prevent non-specific adsorption of proteins. As the strategy outlined in this work is general, we anticipate that it can be further extended to prepare Janus particles with tailored interfacial properties for biomedical, cosmetics, and pharmaceutical applications involving emulsions.
水滴分散在氟碳油相中的乳液（水/氟乳液）由于连续相所具有的气体渗透性、化学惰性和生物相容性，成为封装生物活性物质并在受限空间内精确进行反应的有效手段。虽然由全氟聚醚（PFPE）和聚乙二醇（PEG）组成的分子表面活性剂已被用于稳定这些乳液，但这些表面活性剂无法有效防止相邻液滴之间的聚结和交叉污染。在此，我们提出将Janus纳米颗粒（F-SiO-PEG）作为生物相容性胶体表面活性剂，以在水/氟乳液中实现优异的稳定性。通过使用单层蜡胶体囊泡作为模板，我们表明可以高纯度合成具有两种独特表面润湿性的Janus二氧化硅纳米颗粒。此外，我们证明这些Janus颗粒的额外聚乙二醇化使这些胶体表面活性剂能够强烈粘附在水/氟界面处，与等效的随机功能化纳米颗粒相比，具有优异的乳液稳定性，并防止蛋白质的非特异性吸附。由于本文所述策略具有通用性，我们预计它可以进一步扩展，以制备具有定制界面性质的Janus颗粒，用于涉及乳液的生物医学、化妆品和制药应用。
