Cyclodextrin-based supramolecular nanoparticles for biomedical applications.

Supramolecular host-guest interactions are ideal for engineering supramolecular nanoparticles (SNPs), because their modular character offers the possibility of using the same basic SNPs made of very similar building blocks in a variety of applications. The most widely used host is cyclodextrin (CD), therefore, this review will focus on SNPs involving CD as the host entity. In the first part, particle formation and size control are described, and the forces that induce the assembly between the different components and, therefore, result in the formation of stable and controllable nanoparticles.

Loading and release of fluorescent oligoarginine peptides into/from pH-responsive anionic supramolecular nanoparticles.

Supramolecular nanoparticles (SNPs) based on negatively charged polymeric components can act as pH-responsive systems which allow the encapsulation and release of a positively charged cargo by electrostatic interactions. Fluorescent SNPs, based on the negatively charged poly(isobutyl-alt-maleic acid) and labeled with rhodamine B, were used as carriers to encapsulate positively charged Arg peptides grafted with a cyanine dye. The energy transfer (FRET) between the dyes residing in a single particle was used to provide a sensing mechanism to study the encapsulation and release of the peptide cargo into/from the SNPs.

Fluorescent supramolecular nanoparticles signal the loading of electrostatically charged cargo.

Fluorescently labeled supramolecular nanoparticles (SNPs) were used to study the effects of their loading with oppositely charged cargo. SNPs shrank until neutralization, upon which they destabilized and aggregated. Using a dye-labelled guest, FRET occurred between the SNPs and a dye-labeled cargo.

Cyclodextrin-based supramolecular nanoparticles stabilized by balancing attractive host-guest and repulsive electrostatic interactions.

Multicomponent, negatively charged supramolecular nanoparticles (SNPs) were formed by multivalent host-guest interactions without the need of a stopper in water and in PBS. Their size and stability are controlled owing to a balance of forces between attractive supramolecular and repulsive electrostatic interactions.