Mulet Xavier, Gong Xiaojuan, Waddington Lynne J, Drummond Calum J
CSIRO Molecular and Health Technologies, Bag 10, Clayton South MDC, VIC 3169, Australia.
ACS Nano. 2009 Sep 22;3(9):2789-97. doi: 10.1021/nn900671u.
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.
未来的纳米级软物质设计将由分层自组装和长寿命非平衡态的生物学范式驱动。为了可重复地控制未来纳米材料的低能自组装，我们必须首先汲取生物学的经验教训。许多细胞器呈现出高度有序的立方膜结构。确定这种脂质细胞器复杂性的机制起源一直难以捉摸。我们报告了首次观察到从一维层状膜转变为三维反相双连续立方纳米结构的主要转变的完整序列。通过向脂质纳米颗粒分散体中添加空间稳定剂来实现表征，这增加了非常短寿命的非平衡中间结构的寿命。通过使用同步加速器小角X射线散射和冷冻透射电子显微镜，我们观察并表征了初始脂质双层接触和茎的形成，随后是膜孔的发展、孔演变成二维六方堆积晶格，最后形成三维双连续立方结构。
