ABSTRACT
Compartments based on giant unilamellar vesicles (GUVs) provide a suitable model system for mimicking the cell membrane but are characterized by poor chemical and mechanical stability, and therefore have limited potential for manipulation. Compartments based on block copolymer-stabilized water-in-oil droplets have a potential to overcome these drawbacks. This chapter describes a recently developed approach that merges lipid vesicle formation and droplet microfluidics for the generation of stable, uniformly sized and easily manipulated droplet-supported GUV (dsGUV) compartments. The approach involves microfluidics-based production of droplets stabilized by the copolymer surfactants, in which liposome-containing aqueous solution is encapsulated. In the presence of divalent ions, the liposomes adsorb and fuse to the inner droplet surface forming a 3D supported bilayer, i.e., a dsGUV. Lipid mobility in dsGUVs is similar to that in the free-standing bilayer of GUVs. An advantage of the dsGUV system is that microfluidic pico-injection technology can be applied to deliver controllable amounts of biomaterials in their interior. For example, proteoliposomes can be injected into the copolymer-stabilized emulsion droplets and thus form biofunctionalized dsGUVs with reconstituted proteins. Their size can be precisely controlled and the GUVs can be released from the droplets.
