Dendrimers with Hydrophobic Cores and the Formation of Supramolecular Dendrimer−Surfactant Assemblies

Abstract

The structure of a series of poly(amidoamine) dendrimers Gn(C12) generated from a diaminododecane core have been investigated using the photophysical properties of an external dye, nile red. The modified dendrimers Gn(C12) show the ability to host the hydrophobic dye, nile red, in aqueous solution. The ability of Gn(C12) to host nile red has been compared to corresponding amino-core Gn(NH3) and diaminoethane-core Gn(C2) dendrimers of the same generation size. The emission of nile red in aqueous media is significantly enhanced in the presence of Gn(C12) and not at all for Gn(NH3) and Gn(C2). These results imply a strong tendency for the nile red probe to associate with the long methylene chain of the modified dendrimers in aqueous solutions. Moreover, the interactions of these dendrimers with anionic surfactants generate supramolecular assemblies which greatly enhance their ability to accomodate the nile red. Fluorescence polarization and emission as a function of pH were also studied in an effort to elucidate the interaction of the nile red probe with the dendrimer−surfactant assemblies.

New Approaches Towards Monoamino Polyglycerol Dendrons and Dendritic Triblock Amphiphiles

“…[13] It is known that the fluorescence of Nile Red strongly depends on the polarity of the environment, being redshifted and strongly quenched in polar solvents and approaching a maximum blueshift and intensity in apolar solvents/environment. [14] The remarkable sensitivity of Nile Red has also been beneficial in studies of the local polarity of bolaamphihiles [15] and micelles [16] and of interactions with cyclodextrins. [17] Small changes in the organization of the surfactants in the solvent system could be monitored by Nile Red, [16c] while the specific properties of Nile Red could also be used to characterize surfactant/amphiphiles self-assembly processes and phase behavior.…”

Partial shell-filled core-shell tecto(dendrimers): A strategy to surface differentiated nano-clefts and cusps

“…Access to this level of macromolecular structure control has created substantial interest in the use of dendrimer structures as unimolecular mimics of micelles (11,28,29), globular proteins (30,31), and a variety of other biological self-assemblies (32). Dendrimers have exhibited both endo-and exo-type receptor properties (28,29,33) as unimolecular micelle mimics (11,34,35).…”

“…Dendrimers have exhibited both endo-and exo-type receptor properties (28,29,33) as unimolecular micelle mimics (11,34,35). More recently, amphiphilic dendrimers have led to a new and extensive area of supramacromolecular assemblies, which have been reviewed elsewhere (34,36).…”

A Convergent Approach to Biocompatible Polyglycerol “Click” Dendrons for the Synthesis of Modular Core–Shell Architectures and Their Transport Behavior

“…[31] The remarkable sensitivity of Nile red was beneficial in studying the local polarity of bolaamphihiles, [32] micelles, [33] and interactions with cyclodextrins. [34] Small changes in the organization of the surfactants in the solvent system could be monitored [%]…”