Degen Patrick, Wieland D C Florian, Strötges Christian
Institut für Physikalische Chemie II, Technische Universität Dortmund , Otto-Hahn-Str. 6, 44227 Dortmund, Germany.
Institut für Metallische Biomaterialien, Helmholtz Zentrum Geestacht , Max-Planck Straße 1, 21502 Geesthacht, Germany.
Langmuir. 2015 Nov 3;31(43):11851-7. doi: 10.1021/acs.langmuir.5b02702. Epub 2015 Oct 22.
Nonionic dendritic amphiphiles that self-assemble into defined supramolecular aggregates are useful for the efficient solubilization of active agents, for example, in drug delivery. We investigated a new class of dendritic amphiphiles based on a hydrophilic polyol dendron head connected to a two-chain hydrophobic block. In analogy to phospholipids, these molecules form well-organized layers in bulk (vesicles) or at the water surface (Langmuir monolayer). The actual study focuses on the phase behavior and microscopic structure of mixed Langmuir layers of theses dendritic amphiphiles with the well-known phospholipid DPPC. The combination of surface pressure area isotherms with X-ray grazing incident diffraction and Brewster angle microscopy gives us information on the phase behavior of the mixed monolayers and the orientation of the amphiphiles inside the condensed domains with molecular resolution. We could prove that the dendritic generation and, by this, the headgroup size of the amphiphilic molecules have a significant influence on their interaction with DPPC at the air-water interface. Thus, our findings are important for the understanding of mixed lipid membranes in general as well as for the preparation of artificial membranes and vesicles with adjustable properties, e.g., their drug delivery potential.
能自组装成特定超分子聚集体的非离子型树枝状两亲分子，在活性剂的高效增溶方面很有用，例如在药物递送中。我们研究了一类新型的树枝状两亲分子，其基于连接到双链疏水嵌段的亲水性多元醇树枝状端基。与磷脂类似，这些分子在本体中（形成囊泡）或在水表面（形成朗缪尔单层）形成有序的层。实际研究聚焦于这些树枝状两亲分子与著名的磷脂二棕榈酰磷脂酰胆碱（DPPC）的混合朗缪尔层的相行为和微观结构。表面压力 - 面积等温线与X射线掠入射衍射和布鲁斯特角显微镜的结合，为我们提供了关于混合单层的相行为以及凝聚域内两亲分子取向的分子分辨率信息。我们能够证明树枝状代数，进而两亲分子的头基大小，对它们在气 - 水界面与DPPC的相互作用有显著影响。因此，我们的发现对于总体上理解混合脂质膜以及制备具有可调性质（例如其药物递送潜力）的人工膜和囊泡很重要。
