Observing self-assembled lipid nanoparticles building order and complexity through low-energy transformation processes.
Future nanoscale soft matter design will be driven by the biological paradigms of hierarchical self-assembly and long-lived nonequilibrium states. To reproducibly control the low-energy self-assembly of nanomaterials for the future, we must first learn the lessons of biology. Many cellular organelles exhibit highly ordered cubic membrane structures. Determining the mechanistic origins of such lipid organelle complexity has been elusive. We report the first observation of the complete sequence of major transformations in the conversion from a 1D lamellar membrane to 3D inverse bicontinuous cubic nanostructure. Characterization was enabled by adding a steric stabilizer to dispersions of lipid nanoparticles which increased the lifetime of very short-lived nonequilibrium intermediate structures. By using synchrotron small-angle X-ray scattering and cryo-transmission electron microscopy we observed and characterized initial lipid bilayer contacts and stalk formation, followed by membrane pore development, pore evolution into 2D hexagonally packed lattices, and finally creation of 3D bicontinuous cubic structures.
Mulet
Xavier
X
CSIRO Molecular and Health Technologies, Bag 10, Clayton South MDC, VIC 3169, Australia.
Gong
Xiaojuan
X
Waddington
Lynne J
LJ
Drummond
Calum J
CJ
D002462:Cell Membrane / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D053838:Scattering, Small Angle; D014961:X-Ray Diffraction
D008051:Lipid Bilayers; D011108:Polymers