Progress in the direct structural characterization of fibrous amphiphilic supramolecular assemblies in solution by transmission electron microscopic techniques

• Published in: Advances in colloid and interface science Vol. 208; pp. 279 - 292
• Main Authors: Berlepsch, Hans v., Ludwig, Kai, Schade, Boris, Haag, Rainer, Böttcher, Christoph
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.06.2014; Elsevier
• Subjects: 3D reconstruction; Amino acids; Assemblies; Carbohydrates; Chemical Phenomena; Chemistry; Chirality; Cryo-electron tomography; Cryoelectron Microscopy; Cryogenic transmission electron microscopy; Dyes; Exact sciences and technology; Fibrous structure; General and physical chemistry; Hydrophobic and Hydrophilic Interactions; Imaging, Three-Dimensional; Microscopy, Electron, Transmission; Models, Chemical; Nanofibers - chemistry; Nanofibers - ultrastructure; Nanotechnology - trends; Ribbon; Self assembly; Solubility; Surface-Active Agents - chemistry; Three dimensional; Tube; Tubes; Cryo-electron tomography; Tube; 3D reconstruction; Ribbon; Cryogenic transmission electron microscopy; Chirality; Self assembly; Amphiphilic compound; Characterization; Transmission electron microscopy; Molecular assembly; Supramolecular structure; Tomography
• ISSN: 0001-8686; 1873-3727; 1873-3727
• DOI: 10.1016/j.cis.2014.01.007

The self-assembly of amphiphilic molecules into fibrous structures has been the subject of numerous studies over past decades due to various current and promising technical applications. Although very different in their head group chemistry many natural as well as synthetic amphiphilic compounds derived from carbohydrates, carbocyanine dyes, or amino acids tend to form fibrous structures by molecular self-assembly in water predominantly twisted ribbons or tubes. Often a transition between these assembly structures is observed, which is a phenomenon already theoretically approached by Wolfgang Helfrich and still focus point in current research. With the development of suitable sample preparation and electron optical imaging techniques, cryogenic transmission electron microscopy (cryo-TEM) in combination with three-dimensional (3D) reconstruction techniques has become a particular popular direct characterization technique for supramolecular assemblies in general. Here we review the recent progress in deriving precise structural information from cryo-TEM data of particularly fibrous structures preferably in three dimensions. [Display omitted] •Recent advances in TEM techniques for radiation sensitive materials are presented.•Image averaging and 3D reconstruction techniques are introduced.•Amphiphiles of different molecular architecture serve as exemplary model systems.•Examples for the complementary structural characterization of supramolecular assemblies are given.