Programmable Nanoassemblies from Non-Assembling Homopolymers Using Ad Hoc Electrostatic Interactions.

Robust nanostructures were obtained from polymers that otherwise do not assemble by using a novel approach based on electrostatic self-assembly. The essence of this strategy involves the use of divalent counterions to temporarily perturb the packing features of the ionic groups in a homopolymer, which results in a vesicle-like structure that is captured in situ through a simple crosslinking reaction. The fidelity of the assembly has been tested for molecular transport across the nanomembrane, both for the molecules encapsulated in the lumen and for those trapped in the membrane itself.

Protein-triggered supramolecular disassembly: insights based on variations in ligand location in amphiphilic dendrons.

We use monodisperse dendrons that allow control over functional group presentation to investigate the influence of the location of a ligand on protein-induced disassembly and release of encapsulated small molecules. Based on both experiments and molecular dynamics simulations, we demonstrate that ligand location greatly influences release of guest molecules from the dendron-based supramolecular assembly. We show that a ligand moiety grafted to the dendron periphery is more accessible for the target protein in aqueous solution.

Dual Stimuli - Dual Response Nanoassemblies Prepared from a Simple Homopolymer.

A dual stimuli responsive nanogel-polyelectrolyte complex based on electrostatic coating has been developed. The nanoassembly is designed to elicit two disparate responses ( surface property change and guest encapsulation stability) from two different stimuli ( pH and redox variations). The components of the nanogel and the polyelectrolyte have been conveniently achieved from a simple homopolymer, poly(pentafluorophenylacrylate).

Supramolecular displacement-mediated activation of a silent fluorescence probe for label-free ligand screening.

We report a new approach for the rapid screening of analyte binding affinities for a target protein. We demonstrate that a molecular probe, with a pro-fluorophore substrate and ligand moieties, can be hindered from enzymatic access when bound to the target protein. When analytes displace the probe from the protein's binding pocket, a fluorescence profile is generated.

Stimuli Sensitive Amphiphilic Dendrimers.

In the past decade, there has been an increasing interest in supramolecular systems that can undergo physical or chemical tranformations upon encountering a specific stimulus. Micelle-forming amphiphilic systems based on polymers and dendrimers are particularly preferred over small molecule amphiphiles, due to their ability to sequester and release a vast library of hydrophobic guest molecules at micromolar polymer or dendrimer concentrations. Here we review a relatively underexplored, yet rapidly advancing, field of amphiphilic systems based on dendritic architechture that exhibit stimuli sensitive behaviour.