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Effects of Antifungal Carriers Based on Chitosan-Coated Iron Oxide Nanoparticles on Microcosm Biofilms
Anne Caroline Morais Caldeirão1, Heitor Ceolin Araujo2, Camila Miranda Tomasella3
1Graduate Program in Dentistry (GPD-Master's Degree), University of Western São Paulo (UNOESTE), Presidente Prudente 19050-920, Brazil.
Abstract:
Resistance of Candida species to conventional therapies has motivated the development of antifungal nanocarriers based on iron oxide nanoparticles (IONPs) coated with chitosan (CS). This study evaluates the effects of IONPs-CS as carriers of miconazole (MCZ) or fluconazole (FLZ) on microcosm biofilms. Pooled saliva from two healthy volunteers supplemented with C. albicans and C. glabrata was the inoculum for biofilm formation. Biofilms were formed for 96 h on coverslips using the Amsterdam Active Attachment model, followed by 24 h treatment with nanocarriers containing different concentrations of each antifungal (78 and 156 µg/mL). MCZ or FLZ (156 µg/mL), and untreated biofilms were considered as controls. Anti-biofilm effects were evaluated by enumeration of colony-forming units (CFUs), composition of the extracellular matrix, lactic acid production, and structure and live/dead biofilm cells (confocal laser scanning microscopy-CLSM). Data were analyzed by one-way ANOVA and Fisher LSD's test (α = 0.05). IONPs-CS carrying MCZ or FLZ were the most effective treatments in reducing CFUs compared to either an antifungal agent alone for C. albicans and MCZ for C. glabrata. Significant reductions in mutans streptococci and Lactobacillus spp. were shown, though mainly for the MCZ nanocarrier. Antifungals and their nanocarriers also showed significantly higher proportions of dead cells compared to untreated biofilm by CLSM (p < 0.001), and promoted significant reductions in lactic acid, while simultaneously showing increases in some components of the extracellular matrix. These findings reinforce the use of nanocarriers as effective alternatives to fight oral fungal infections.
Insights
Iron oxide nanoparticles coated with chitosan effectively deliver antifungals like miconazole and fluconazole, significantly reducing Candida biofilms and promoting cell death. These nanocarriers show promise against resistant oral fungal infections.
Area of Science:
- Biomaterials Science
- Mycology
- Nanotechnology
Background:
- Growing resistance of *Candida* species to conventional antifungal therapies necessitates novel treatment strategies.
- Iron oxide nanoparticles (IONPs) coated with chitosan (CS) offer a promising platform for targeted drug delivery.
- Antifungal nanocarriers can potentially enhance the efficacy of existing drugs like miconazole (MCZ) and fluconazole (FLZ).
Purpose of the Study:
- To evaluate the anti-biofilm efficacy of IONPs-CS loaded with MCZ or FLZ against *Candida* species in microcosm biofilms.
- To compare the effectiveness of these nanocarriers against free antifungals and untreated controls.
- To assess the impact of nanocarrier treatment on biofilm composition, metabolic activity, and cell viability.
Main Methods:
- Biofilm formation using *C. albicans* and *C. glabrata* in a pooled saliva microcosm model.
- Treatment of mature biofilms with different concentrations of MCZ- or FLZ-loaded IONPs-CS.
- Assessment of anti-biofilm activity via colony-forming unit (CFU) counts, extracellular matrix analysis, lactic acid production, and confocal laser scanning microscopy (CLSM) for live/dead cells.
Main Results:
- IONPs-CS loaded with MCZ or FLZ demonstrated superior reduction in CFUs compared to antifungals alone against *C. albicans* and *C. glabrata* (MCZ).
- Significant reductions in *Streptococcus mutans* and *Lactobacillus* spp. were observed, particularly with the MCZ nanocarrier.
- CLSM revealed a significantly higher proportion of dead biofilm cells with nanocarrier treatments, alongside reduced lactic acid production and altered extracellular matrix composition.
Conclusions:
- IONPs-CS nanocarriers effectively deliver antifungals, enhancing their efficacy against *Candida* biofilms.
- These nanocarriers represent a viable alternative strategy for combating challenging oral fungal infections.
- The developed nanocarrier system shows potential for improved therapeutic outcomes in managing *Candida* related oral pathologies.
