Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849, USA.
Soft Matter. 2020 Mar 4;16(9):2177-2184. doi: 10.1039/c9sm02254f.
Presented herein is the first report on dipolar Janus liposomes-liposomes that contain opposite surface charges decorating the two hemispheres of the same colloidal body. Such heterogeneous organization of surface charge is achieved through cholesterol-modulated lipid phase separation, which sorts anionic/cationic lipids into coexisting liquid-ordered/liquid-disordered domains. We present optimized experimental conditions to produce these liposomes in high yields, based on the gel-assisted hydration of ternary lipid systems consisting of cholesterol, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, and 1,2-dioleoyl-sn-glycero-3-phosphocholine. The size/charge distribution and domain configuration of these liposomes are characterized in detail by confocal fluorescence microscopy, nanosphere binding and zeta potential measurements. Using confocal fluorescence microscopy, we also follow the electrokinetic motion as well as the electrostatic self-assembly of these new dipolar Janus particles.
本文首次报道了偶极 Janus 脂质体——即含有相反表面电荷的脂质体，其表面电荷分布于同一胶体粒子的两个半球。这种异质的表面电荷组织方式是通过胆固醇调节的脂质相分离实现的，这种相分离将阴离子/阳离子脂质分类为共存的液晶有序/液晶无序域。我们提出了优化的实验条件，基于胆固醇、1,2-二棕榈酰基-sn-甘油-3-磷酸胆碱和 1,2-二油酰基-sn-甘油-3-磷酸胆碱组成的三元脂质体系的凝胶辅助水合作用，以高产率制备这些脂质体。通过共聚焦荧光显微镜、纳米球结合和 zeta 电位测量，详细表征了这些脂质体的尺寸/电荷分布和域结构。通过共聚焦荧光显微镜，我们还跟踪了这些新型偶极 Janus 颗粒的电动运动和静电自组装。
