Multivalency in a Dendritic Host–Guest System

Abstract

Multivalency is an important instrument in the supramolecular chemistry toolkit for the creation of strong specific interactions. In this paper we investigate the multivalency effect in a dendritic host–guest system using molecular dynamics simulations. Specifically, we consider urea–adamantyl decorated poly(propyleneimine) dendrimers that together with compatible mono-, bi-, and tetravalent ureidoacetic acid guests can form dynamic patchy nanoparticles. First, we simulate the self-assembly of these particles into macromolecular nanostructures, showing guest-controlled reduction of dendrimer aggregation. Subsequently, we systematically study guest concentration dependent multivalent binding. At low guest concentrations multivalency of the guests clearly increases relative binding as tethered headgroups bind more often than free guests’ headgroups. We find that despite an abundance of binding sites, most of the tethered headgroups bind in close proximity, irrespective of the spacer length; nevertheless, longer spacers do increase binding. At high guest concentrations the dendrimer becomes saturated with bound headgroups, independent of guest valency. However, in direct competition the tetravalent guests prevail over the monovalent ones. This demonstrates the benefit of multivalency at high as well as low concentrations.

Nanoarchitectonics horizons: materials for life sciences

“…Amphiphilic dendrimers have the advantage of multivalency using hydrophobic and hydrophilic heads through which strong interactions can be achieved between the host-guest system. 71 Highly stable human membrane vesicles with dendrimersomes were fabricated using a co-assembly containing a Fig. 5 The process of moving from a dendrimer to a supramolecular structure via self-assembly for the cellular uptake of siRNA for gene silencing.…”

“…Amphiphilic dendrimers have the advantage of multivalency using hydrophobic and hydrophilic heads through which strong interactions can be achieved between the host–guest system. 71 Highly stable human membrane vesicles with dendrimersomes were fabricated using a co-assembly containing a human cell membrane and a Janus dendrimer for targeting bacterial adhesion proteins. 72 Likewise, amine-terminated PAMAM dendrimers were conjugated with donepezil for effective delivery to the brain.…”