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.

中文翻译：

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一种纳米载体系统，可增强咪康唑在不同界间生物膜中的作用。

摘要

背景

能够增强现有抗微生物剂功效的新颖和新的治疗策略是满足社会需求的有吸引力的主张。

客观的

本研究旨在评估咪康唑 (MCZ) 纳米载体系统的增强作用，该系统与氧化铁纳米粒子 (IONPs) 和壳聚糖 (CS) (IONPs-CS-MCZ) 结合。这在三个具有代表性的复杂跨界口腔生物膜模型（龋齿、假牙和牙龈炎）上进行了测试。

材料和方法

确定了 IONPs-CS-MCZ 对不同白色念珠菌菌株以及在三种生物膜模型中形成的所有代表细菌种类的浮游和固着最小抑制浓度 (MIC)。使用含有 64 mg/L MCZ 的 IONPs-CS 纳米载体系统处理生物膜 24 小时，并使用一系列生物测定来进行定量和定性评估。

结果

MIC结果普遍表明IONPs-CS-MCZ比单独的MCZ更有效。与未处理的生物膜相比，IONPs-CS-MCZ 还促进了代表性生物膜的 CFU 数量、生物量和代谢活性的减少，以及改变生物膜超微结构。IONPs-CS-MCZ 影响了三种评估生物膜中存在的大多数微生物的组成并降低了 CFE。特别是，在所有三种模型中，生物膜成分中链球菌的比例都降低了，而梭杆菌属。牙龈炎和龋齿模型中的百分比分别降低。

结论

总之，IONPs-CS-MCZ 纳米载体对三种致病性口腔生物膜体外模型有效，显示出可能干扰多微生物菌群内真菌和细菌细胞之间的协同相互作用的潜力。