Kinetic switching between two modes of bisurea surfactant self-assembly.

The size and shape of a surfactant aggregate could be altered by using supersaturation like in crystal growth, rather than applying common laws that drive surfactant aggregate formation.

Insights into templated supramolecular polymerization: binding of naphthalene derivatives to ssDNA templates of different lengths.

We report on two diaminotriazine-equipped naphthalene derivatives that bind reversibly to a single-stranded DNA template or "tape-measure molecule" via hydrogen bonding, yielding monodisperse double-stranded DNA hybrids with one strand consisting of a supramolecular naphthalene backbone. These assemblies have been investigated extensively, both experimentally and theoretically. The structure and the templated self-assembly process of the complex have been characterized with UV-vis spectroscopy, circular dichroism spectroscopy, molecular dynamics simulations, cryo-transmission electron microscopy, liquid atomic force microscopy, electrospray ionization mass spectrometry, light scattering, and 1H NMR and infrared spectroscopy.

Electron tomography shows molecular anchoring within a layer-by-layer film.

The layer-by-layer self-assembly of thin films consisting of alternating layers of DNA and bis-urea nanoribbons prevents diffusion of the components within the film and allows the anchoring of biotinylated molecules through molecular recognition in a predetermined layer of the film. Electron tomography demonstrates with nanometer precision the location of gold-labeled streptavidin bound to the incorporated biotinylated molecules.

Stepwise noncovalent synthesis leading to dendrimer-based assemblies in water.

We provide detailed insight into complex supramolecular assembly processes by fully characterizing a multicomponent model system using dynamic light scattering, cryogenic transmission electron microscopy, atomic force microscopy, and various NMR techniques. First, a preassembly of a host molecule (the fifth-generation urea-adamantyl poly(propylene imine) dendrimer) and 32 guest molecules (a water- and chloroform-soluble ureidoacetic acid guest) was made in chloroform. The association constant in chloroform is concealed by guest self-association and is therefore higher than 10(3) M(-1).

Molecular recognition controls the organization of mixed self-organized bis-urea-based mineralization templates for CaCO(3).

To investigate the role and importance of nondirectional electrostatic interactions in mineralization, we explored the use of Langmuir monolayers in which the charge density can be tuned using supramolecular interactions. It is demonstrated that, in mixed Langmuir monolayers of bis-ureido surfactants containing oligo(ethylene oxide) and ammonium head groups associated with matching or nonmatching spacers between the two urea groups, the organization is controlled by molecular recognition. These different organizations of the molecules lead to different nucleation behavior in the mineralization of calcium carbonate.

In vitro and in vivo effects of deoxyribonucleic acid-based coatings funtionalized with vascular endothelial growth factor.

Vascularization is important in wound healing and essential for tissue ingrowth into porous tissue-engineering matrices. Furthermore, peri-implant tissue vascularization is known to be important for the functionality of subcutaneously implanted biosensors (e.g.

The bis-urea motif as a tool to functionalize self-assembled nanoribbons.

Here we present a surfactant molecule (1) containing an ammonium headgroup, in which a bis-ureido group is incorporated in its hydrocarbon chain. Due to strong hydrogen bonding interactions, 1 forms well-defined highly ordered ribbon-like aggregates in water. Moreover, we demonstrate that these ribbons can be functionalized via a modular approach through molecular recognition of other bis-urea containing molecules.

Fabrication, characterization, and biological assessment of multilayered DNA-coatings for biomaterial purposes.

This study describes the fabrication of two types of multilayered coatings onto titanium by electrostatic self-assembly (ESA), using deoxyribosenucleic acid (DNA) as the anionic polyelectrolyte and poly-d-lysine (PDL) or poly(allylamine hydrochloride) (PAH) as the cationic polyelectrolyte. Both coatings were characterized using UV-vis spectrophotometry, atomic force microscopy (AFM), X-ray photospectroscopy (XPS), contact angle measurements, Fourier transform infrared spectroscopy (FTIR), and for the amount of DNA immobilized. The mutagenicity of the constituents of the coatings was assessed.