title: Octanol-assisted liposome assembly on chip.
abstract: Liposomes are versatile supramolecular assemblies widely used in basic and applied sciences. Here we present a novel microfluidics-based method, octanol-assisted liposome assembly (OLA), to form monodisperse, cell-sized (5-20 μm), unilamellar liposomes with excellent encapsulation efficiency. Akin to bubble blowing, an inner aqueous phase and a surrounding lipid-carrying 1-octanol phase is pinched off by outer fluid streams. Such hydrodynamic flow focusing results in double-emulsion droplets that spontaneously develop a side-connected 1-octanol pocket. Owing to interfacial energy minimization, the pocket splits off to yield fully assembled solvent-free liposomes within minutes. This solves the long-standing fundamental problem of prolonged presence of residual oil in the liposome bilayer. We demonstrate the unilamellarity of liposomes with functional α-haemolysin protein pores in the membrane and validate the biocompatibility by inner leaflet localization of bacterial divisome proteins (FtsZ and ZipA). OLA offers a versatile platform for future analytical tools, delivery systems, nanoreactors and synthetic cells.
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
authors.forename: Siddharth
authors.initials: S
authors.lastname: Deshpande
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
authors.forename: Yaron
authors.initials: Y
authors.lastname: Caspi
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
authors.forename: Anna E C
authors.initials: AE
authors.lastname: Meijering
authors.affiliation: Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
authors.forename: Cees
authors.initials: C
authors.lastname: Dekker
mesh_terms: D029968:Escherichia coli Proteins / Q000737:chemistry; D006460:Hemolysin Proteins / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D044085:Microfluidics / Q000295:instrumentation / Q000379:methods*; D000442:Octanols / Q000737:chemistry*; D053835:Unilamellar Liposomes / Q000737:chemistry*
chemical_list: D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; C036507:Hlya protein, E coli; D008055:Lipids; D000442:Octanols; D053835:Unilamellar Liposomes