Forming giant vesicles with controlled membrane composition, asymmetry, and contents

Proc Natl Acad Sci U S A. 2011 Jun 7;108(23):9431-6. doi: 10.1073/pnas.1016410108. Epub 2011 May 18.


Growing knowledge of the key molecular components involved in biological processes such as endocytosis, exocytosis, and motility has enabled direct testing of proposed mechanistic models by reconstitution. However, current techniques for building increasingly complex cellular structures and functions from purified components are limited in their ability to create conditions that emulate the physical and biochemical constraints of real cells. Here we present an integrated method for forming giant unilamellar vesicles with simultaneous control over (i) lipid composition and asymmetry, (ii) oriented membrane protein incorporation, and (iii) internal contents. As an application of this method, we constructed a synthetic system in which membrane proteins were delivered to the outside of giant vesicles, mimicking aspects of exocytosis. Using confocal fluorescence microscopy, we visualized small encapsulated vesicles docking and mixing membrane components with the giant vesicle membrane, resulting in exposure of previously encapsulated membrane proteins to the external environment. This method for creating giant vesicles can be used to test models of biological processes that depend on confined volume and complex membrane composition, and it may be useful in constructing functional systems for therapeutic and biomaterials applications.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Biological Transport
  • Green Fluorescent Proteins / chemistry
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Kinetics
  • Membrane Lipids / chemistry*
  • Membrane Lipids / metabolism
  • Membrane Proteins / chemistry*
  • Membrane Proteins / metabolism
  • Microfluidics / methods*
  • Microscopy, Confocal
  • Models, Chemical
  • Models, Molecular
  • Phosphatidylcholines / chemistry
  • Phosphatidylcholines / metabolism
  • Phosphatidylinositol 4,5-Diphosphate / chemistry
  • Phosphatidylinositol 4,5-Diphosphate / metabolism
  • Porosity
  • Protein Binding
  • Qa-SNARE Proteins / chemistry
  • Qa-SNARE Proteins / metabolism
  • R-SNARE Proteins / chemistry
  • R-SNARE Proteins / genetics
  • R-SNARE Proteins / metabolism
  • Rats
  • Rhodamines / chemistry
  • Rhodamines / metabolism
  • SNARE Proteins / chemistry
  • SNARE Proteins / metabolism
  • Unilamellar Liposomes / chemistry*
  • Unilamellar Liposomes / metabolism


  • Membrane Lipids
  • Membrane Proteins
  • Phosphatidylcholines
  • Phosphatidylinositol 4,5-Diphosphate
  • Qa-SNARE Proteins
  • R-SNARE Proteins
  • Rhodamines
  • SNARE Proteins
  • Unilamellar Liposomes
  • Green Fluorescent Proteins
  • 1,2-diphytanoylphosphatidylcholine
  • tetramethylrhodamine