São Paulo State University (Unesp), School of Dentistry, Araçatuba, Department of Pediatric Dentistry and Public Health, 16015-050 Araçatuba, São Paulo, Brazil.
Federal University of São Carlos, Department of Chemistry, 13565-905 São Carlos, São Paulo, Brazil.
Colloids Surf B Biointerfaces. 2019 Feb 1;174:224-231. doi: 10.1016/j.colsurfb.2018.11.023. Epub 2018 Nov 12.
This study synthesized and characterized a chlorhexidine (CHX)-carrier nanosystem based on iron oxide magnetic nanoparticles (IONPs) and chitosan (CS), and evaluated its antimicrobial effect on mono- and dual-species biofilms of Candida albicans and Streptococcus mutans. CHX was directly solubilized in CS-coated IONPs and maintained under magnetic stirring for obtaining the IONPs-CS-CHX nanosystem. Antimicrobial susceptibility testing for planktonic cells was performed by determining the minimum inhibitory concentration (MIC) of the nanosystem and controls. The effects of the IONPs-CS-CHX nanosystem on the formation of mono- and dual-species biofilms, as well as on pre-formed biofilms were assessed by quantification of total biomass, metabolic activity and colony-forming units. Data were analyzed by the Kruskal-Wallis' test or one-way analysis of variance, followed by the Student-Newman-Keuls' or Holm-Sidak's tests (α = 0.05), respectively. Physico-chemical results confirmed the formation of a nanosystem with a size smaller than 40 nm. The IONPs-CS-CHX nanosystem and free CHX showed similar MIC values for both species analyzed. In general, biofilm quantification assays revealed that the CHX nanosystem at 78 μg/mL promoted similar or superior antibiofilm effects compared to its counterpart at 39 μg/mL and free CHX at 78 μg/mL. These findings highlight the potential of CS-coated IONPs as preventive or therapeutic agents carrying CHX to fight biofilm-associated oral diseases.
本研究合成并表征了一种基于氧化铁磁性纳米粒子（IONP）和壳聚糖（CS）的氯己定（CHX）载体纳米系统，并评估了其对白色念珠菌和变形链球菌单种和双种生物膜的抗菌效果。CHX 直接溶解在 CS 包覆的 IONP 中，并在磁力搅拌下保持，以获得 IONP-CS-CHX 纳米系统。通过确定纳米系统和对照物的最小抑菌浓度（MIC），对浮游细胞的抗菌药敏试验进行了测定。通过定量总生物量、代谢活性和菌落形成单位，评估了 IONP-CS-CHX 纳米系统对单种和双种生物膜形成以及预形成生物膜的影响。数据分别通过 Kruskal-Wallis 检验或单向方差分析，然后通过 Student-Newman-Keuls 检验或 Holm-Sidak 检验（α=0.05）进行分析。物理化学结果证实形成了一种尺寸小于 40nm 的纳米系统。IONP-CS-CHX 纳米系统和游离 CHX 对两种分析的物种均显示出相似的 MIC 值。一般来说，生物膜定量测定表明，CHX 纳米系统在 78μg/mL 时，与 39μg/mL 时的相应物和 78μg/mL 时的游离 CHX 相比，具有相似或更优的抗生物膜作用。这些发现强调了 CS 包覆的 IONP 作为携带 CHX 以对抗与生物膜相关的口腔疾病的预防或治疗剂的潜力。
