# Lipid nanocarrier containing eugenol for denture hygiene: evaluation of efficacy against Candida biofilms

## TL;DR

A new eugenol-based nanocarrier was developed to effectively reduce Candida biofilms on dentures, showing better performance than free eugenol.

## Contribution

A nanostructured lipid carrier containing eugenol was developed and shown to have enhanced antifungal efficacy against Candida biofilms.

## Key findings

- NFE nanoparticles had a particle size of 199.5±2.55 nm and high encapsulation efficiency (83.07±0.23%).
- NFE showed 10- to 8-fold lower MIC values than free eugenol against Candida albicans and Candida glabrata.
- NFE significantly reduced Candida biofilms after eight hours compared to other treatments (P<0.0001).

## Abstract

This article is derived from Irisvaldo Lima Guedes's Master's dissertation and is available at the address: https://sigaa.ufpi.br/sigaa/public/programa/noticias_desc.jsf?lc=pt_BR&id=370&noticia=519307121

Eugenol has demonstrated efficacy against Candida spp., which is highly prevalent in denture wearers. However, the low water solubility and high volatility limit its application. The encapsulation in nanostructured lipid carriers (NLCs) may be a viable approach for developing new sanitizing agents for denture hygiene.

To develop a sanitizing dispersion for denture hygiene using nanostructured lipid carriers (NLCs) containing eugenol and to evaluate the efficacy against Candida spp. biofilms.

The formulation was prepared using the ultrasonication method and characterized in terms of particle size (PS), polydispersity index (PDI), zeta potential (ZP), and encapsulation efficiency (EE). The minimum inhibitory concentration (MIC) was determined by the broth microdilution method and the antifungal activity was evaluated by four treatment groups (nanostructured formulation containing eugenol (NFE), free eugenol (FE), saline solution (SS), and the drug-free formulation NFW after eight hours of immersion in biofilms of two Candida species (Candida albicans and Candida glabrata) adhered to polymethyl methacrylate resin specimens.

The nanoparticles of NFE showed a particle size of 199.5±2.55 nanometers (nm) as measured by DLS, high homogeneity (0.07±0.02), an EE of 83.07±0.23, and a negative ZP (-25.86±0.65). The MICs of FE for Candida albicans and Candida glabrata were up to 10 times (64 µg/mL) and eight times (128 µg/mL) higher, respectively, than the MICs of NFE (6 µg/mL and 16 µg/mL). The biofilms of these microorganisms showed a significant reduction after immersion in NFE compared to the other tested groups (FE, NBF, and SS) (P<0.0001).

The NFE demonstrated fungicidal activity against the isolated strains and significantly reduced Candida biofilms, thus showing promising performance for the sanitization of dentures over eight hours.