A highly-yield procedure for preparing microsized (giant) unilamellar Janus liposomes vai gel-assisted lipid swelling are developed. Confocal fluorescence microscopy reveals in detail that these new lipid colloidal particles display broken symmetry and heterogeneous surface chemistry similar to other types of Janus particles. An optimized formation procedure is presented, which reproducibly yields large liposome populations dominated by a single-domain configuration. Functionalized Janus liposomes are obtained by introducing biotin-conjugated lipid or charged lipids. Specifically, the biotin-conjugated 1,2-dioleoyl-<i>sn</i>-glycerol-3-phosphoethanolamine preferentially partitions into the liquid disordered phase of the lipid matrix, rendering these Janus liposomes asymmetrical binding capacity toward avidin. This affinity binding drives irreversible and domain-specific cluster formation among Janus liposomes, whose structure and size are found to depend on the domain configuration of individual liposomes and incubation time. Furthermore, adding negative charged 1,2-dipalmitoyl-<i>sn</i>-glycero-3-phospho-(1’-rac-glycerol) and/or positive charged 1,2-dioleoyl-3-trimethylammonium-propane into lipid matrix lead the formation of mono-charged or di-charged Janus liposomes. Comparing to neutralized Janus liposomes, these charged Janus liposomes show preferential clustering behavior, and salt effects, concentration effects are observed in this system. The electrokinetic motion under DC in microfluidic channel further exhibits the differences of these modified Janus particles.

Janus liposomes: Gel-assisted formation and functionalization

2019 Spring National Meeting

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