A nanocarrier system that potentiates the effect of miconazole within different interkingdom biofilms

Laís Salomão Arias,Jason L Brown,Mark C Butcher,Christopher Delaney,Douglas Roberto Monteiro,Gordon Ramage

doi:10.1080/20002297.2020.1771071

Abstract

ABSTRACT Background Novel and new therapeutic strategies capable of enhancing the efficacy of existing antimicrobials is an attractive proposition to meet the needs of society. Objective This study aimed to evaluate the potentiating effect of a miconazole (MCZ) nanocarrier system, incorporated with iron oxide nanoparticles (IONPs) and chitosan (CS) (IONPs-CS-MCZ). This was tested on three representative complex interkingdom oral biofilm models (caries, denture and gingivitis). Materials and methods The planktonic and sessile minimum inhibitory concentrations (MICs) of IONPs-CS-MCZ against different Candida albicans strains were determined, as well as against all represented bacterial species that formed within the three biofilm models. Biofilms were treated for 24 hours with the IONPs-CS nanocarrier system containing MCZ at 64 mg/L, and characterized using a range of bioassays for quantitative and qualitative assessment. Results MIC results generally showed that IONPs-CS-MCZ was more effective than MCZ alone. IONPs-CS-MCZ also promoted reductions in the number of CFUs, biomass and metabolic activity of the representative biofilms, as well as altering biofilm ultrastructure when compared to untreated biofilms. IONPs-CS-MCZ affected the composition and reduced the CFEs for most of the microorganisms present in the three evaluated biofilms. In particular, the proportion of streptococci in the biofilm composition were reduced in all three models, whilst Fusobacterium spp. percentage reduced in the gingivitis and caries models, respectively. Conclusion In conclusion, the IONPs-CS-MCZ nanocarrier was efficient against three in vitro models of pathogenic oral biofilms, showing potential to possibly interfere in the synergistic interactions among fungal and bacterial cells within polymicrobial consortia.

Highlights

Oral diseases are globally prevalent, and the misdiagnosis or non-treatment of such diseases can result in systemic complications
In conclusion, the iron oxide nanoparticles (IONPs)-CS-MCZ nanocarrier was efficient against three in vitro models of pathogenic oral biofilms, showing potential to possibly interfere in the synergistic interactions among fungal and bacterial cells within polymicrobial consortia
We report for the first time the effect of a MCZ nanocarrier against three different pathogenic biofilm models, first evaluating the minimum inhibitory concentrations (MICs) of MCZ alone and IONPs-CS-MCZ for all studied microorganisms in planktonic form and mono-species biofilms, before assessing the changes in number of cells, biofilm ultrastructure and species composition for the polymicrobial biofilm models following treatment with the nanocarrier system

Summary

Introduction

Oral diseases are globally prevalent, and the misdiagnosis or non-treatment of such diseases can result in systemic complications. The prevalence of denture stomatitis has been increasing in elderly people and denture wearers, as well as immunocompromised patients, and with a drive to maintain natural dentition we have seen a rise in partial dentures in younger adult patients [2,3,4] These biofilm-mediated diseases can all be prevented with effective self-directed oral hygiene measures (biofilm disruption and chemical disinfection), yet unnecessary risk related to human behavior frequently leads to oral disease requiring antimicrobial intervention. Objective: This study aimed to evaluate the potentiating effect of a miconazole (MCZ) nanocarrier system, incorporated with iron oxide nanoparticles (IONPs) and chitosan (CS) (IONPs-CS-MCZ) This was tested on three representative complex interkingdom oral biofilm models (caries, denture and gingivitis)

Objectives

Methods

Results

Conclusion