# Water-Dispersible Supramolecular Nanoparticles Formed by Dicarboxyl-bis-pillar[5]arene/CTAB Host–Guest Interaction as an Efficient Delivery System of Quercetin

## TL;DR

Researchers created water-dispersible nanoparticles to efficiently deliver quercetin, a poorly water-soluble compound, improving its stability and bioavailability.

## Contribution

A novel supramolecular nanoparticle system using dicarboxyl-bis-pillar[5]arene and CTAB for efficient quercetin delivery is introduced.

## Key findings

- The CTAB/H nanoparticles had a size of ~40 nm, positive charge, and high colloidal stability for three months.
- The system efficiently encapsulated quercetin and showed low cytotoxicity with strong antioxidant activity.
- Quercetin-loaded nanoparticles improved cellular uptake and provided cytoprotection against oxidative stress.

## Abstract

Supramolecular nanoparticles offer an efficient strategy to enhance the solubility, stability, and bioavailability of poorly water-soluble therapeutic molecules. In this study, water-dispersible SNPs were successfully prepared from dicarboxyl-bis-pillar[5]arene (H) and cetyltrimethylammonium bromide (CTAB) using a microemulsion method. Dynamic light scattering revealed that the resulting CTAB/H nanoparticles possessed a size distribution centered around 40 nm, a positive surface charge (+15 mV), and exhibited high colloidal stability over three months. 1H NMR, 2D TOCSY, 2D NOESY, diffusion ordered NMR spectroscopy, and UV-Vis investigations confirmed the inclusion of the CTAB alkyl chain within the pillar[5]arene cavity, supporting the formation of stable supramolecular assemblies capable of efficiently encapsulating the poorly water-soluble flavonol quercetin (Q). The CTAB/H system displayed low cytotoxicity (up to 50 µg/mL) and pronounced antioxidant activity, as evidenced by DPPH, ABTS, and FRAP assays. Quercetin-loaded nanoparticles (CTAB/H/Q) enhanced cellular uptake and exhibited a marked cytoprotective effect against H2O2-induced oxidative stress in NIH-3T3 fibroblasts.