Supramolecular polymerization of sulfated dendritic peptide amphiphiles into multivalent L-selectin binders

The synthesis of a sulfate-modified dendritic peptide amphiphile and its self-assembly into one-dimensional rod-like architectures in aqueous medium is reported. The influence of the ionic strength on the supramolecular polymerization was probed via circular dichroism spectroscopy and cryogenic transmission electron microscopy. Physiological salt concentrations efficiently screen the charges of the dendritic building block equipped with eight sulfate groups and trigger the formation of rigid supramolecular polymers. Since multivalent sulfated supramolecular structures mimic naturally occurring L-selectin ligands, the corresponding affinity was evaluated using a competitive SPR binding assay and benchmarked to an ethylene glycol-decorated supramolecular polymer

Affinity chromatography in dynamic combinatorial libraries: one-pot amplification and isolation of a strongly binding receptor

We report the one-pot amplification and isolation of a nanomolar receptor in a multibuilding block aqueous dynamic combinatorial library using a polymer-bound template. By appropriate choice of a poly(N,N-dimethylacrylamide)-based support, unselective ion-exchange type behaviour between the oppositely charged cationic guest and polyanionic hosts was overcome, such that the selective molecular recognition arising in aqueous solution reactions is manifest also in the analogous templated solid phase DCL syntheses. The ability of a polymer bound template to identify and isolate a synthetic receptor via dynamic combinatorial chemistry was not compromised by the large size of the library, consisting of well over 140 theoretical members, demonstrating the practical advantages of a polymer-supported DCL methodology

Preparation and exploitation of tailored polymer resins for use in dynamic combinatial library synthesis

The thermodynamically controlled synthesis, amplification and isolation of macrocydic receptors from dynamic combinatorial libraries (DCLs) has been achieved in a single step using polymer-supported templates. By combining synthesis and affinity chromatography into one single step tedious separations via chromatographic techniques can be avoided, which opens new preparative possibilities especially in more complex libraries comprising an increased number of building blocks.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Supramolecular Chemistry in Polymer Networks

Cross-linked organic materials or polymer networks have found numerous applications and technologies that are indispensable in everyday life. Networks formed via molecular recognition events that act as noncovalent cross-linkers exhibit rather unusual properties due to the dynamic character and tunable strength of the supramolecular interactions. In the first instance, we aim to introduce and discuss complementary functional groups that have been developed to allow for reversible network formation in bulk supramolecular materials. Thereafter, this chapter deals mainly with network formation in macroscopic and particulate gels. In both parts, we highlight how material properties at the meso- and macroscopic scales are governed by noncovalent forces on the molecular level, and how supramolecular interactions can offer opportunities in the fabrication of stimuli-responsive materials. Lead examples and applications are highlighted throughout, for example, in the development of thermoplastic elastomers, coatings, tissue engineering, and drug delivery technologies

Supramolecular Polymers in Aqueous Media

This review discusses one-dimensional supramolecular polymers that form in aqueous media. First, naturally occurring supramolecular polymers are described, in particular, amyloid fibrils, actin filaments, and microtubules. Their structural, thermodynamic, kinetic, and nanomechanical properties are highlighted, as well as their importance for the advancement of biologically inspired supramolecular polymer materials. Second, five classes of synthetic supramolecular polymers are described: systems based on (1) hydrogen-bond motifs, (2) large π-conjugated surfaces, (3) host–guest interactions, (4) peptides, and (5) DNA. We focus on recent studies that address key challenges in the field, providing mechanistic understanding, rational polymer design, important functionality, robustness, or unusual thermodynamic and kinetic properties

Surface-Assisted Self-Assembly of a Hydrogel by Proton Diffusion

International audienceControlling supramolecular growth at solid surfaces is of great importance to expand the scope of supramolecular materials. Here we describe a dendritic benzene-1,3,5-tricarboxamide peptide conjugate whose assembly can be triggered by a pH jump. Stopped flow kinetics and mathematical modeling provide a quantitative understanding of the nucleation, elongation, and fragmentation behavior in solution. To assemble the molecule at a solid-liquid interface, we use proton diffusion from the bulk. The latter needs to be slower than the lag phase of nucleation in order to progressively grow a hydrogel outwards from the surface. Our method of surface-assisted self-assembly is generally applicable to other gelators, and can be used to create structured supramolecular materials

Probing the self-assembly and stability of oligohistidine based rod-like micelles by aggregation induced luminescence

The synthesis and self-assembly of a new C2-symmetric oligohistidine amphiphile equipped with an aggregation induced emission luminophore is reported. We observe the formation of highly stable and ordered rod-like micelles in phosphate buffered saline, with a critical aggregation concentration below 200 nM. Aggregation induced emission of the luminophore confirms the high stability of the anisotropic assemblies in serum.</p

Dynamic Light Scattering Investigation of the Kinetics and Fidelity of Supramolecular Copolymerizations in Water

The self-assembly of supramolecular copolymers facilitates the preparation of multifunctional materials, with tunable mechanical, electronic, or bioactive properties. Compared to covalent copolymerization protocols, controlling the molecular weight, stability, and monomer sequence of a multicomponent supramolecular copolymer remains limited. Here, we report a light scattering investigation of the charge-regulated supramolecular copolymerization in neutral buffer of physiological ionic strength, supported with electron microscopy and circular dichroism spectroscopy experiments. Dendritic anionic and cationic peptide comonomers self-assemble into AB-type heterocopolymers with a nanorod-like morphology, a thickness of 11 nm, and a mean length of up to 70 nm. The fidelity in the copolymerization is remarkably high, and excess of either monomer of up to 50 mol % in the feed ratio does not lead to chain stoppering. The narrow length distribution of the copolymers (<i>Đ</i> < 1.3) and high colloidal stability in physiological buffer support their applications as biomedical carrier materials