Razi Herbal Medicines Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran.
Razi Herbal Medicines Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran; Department of Microbiology, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran.
Carbohydr Polym. 2019 May 15;212:142-149. doi: 10.1016/j.carbpol.2019.02.018. Epub 2019 Feb 7.
Mentha piperita essential oils (MPEO) were loaded into chitosan nanogel to use as antibiofilm agent against Streptococcus mutans and to protect its dental plaque. Chitosan nanoparticles (CsNPs) were prepared by sol-gel method using linking bridge of tripolyphosphate (TPP). Physiological properties of MPEO-CNs were assessed by FTIR, SEM/EDX, DLS and zeta potential. Release kinetics, MIC and MBC were determined for MPEO-CNs. Expression of biofilm-associated genes including 8 genes: grfB, C and D, brpA, spaP, gbpB, relA and vicR was investigated at the presence of sub-MIC of MPEO-CNs. Most abundant bioactive compounds of MPEO were l-menthol (45.05%) and l-menthal (17.53%). SEM/EDX exhibited successful entrapment of MPEO into CsNPs followed by the changes in abundance of elemental peaks. A signal at 1737 cm on chitosan spectrum was attributed to the carboxylic (CO) groups overlapped by MPEO incorporation. A new signal at 2361 cm was assigned to electrostatic interactions of amine groups in chitosan with phosphoric units of TPP within the MPEO-chitosan. MPEO incorporation into porous nanogel decreased monodispersity of the nanoparticles and then raises z-average. Maximum release of MPEO was about 50% during 360 h in a hydroalcoholic solvent at ambient temperature. The adherence of bacterial cells showed high sensitivity to the nanoformulation of MPEO compared with unloaded chitosan-nanogel. Antibiofilm inhibition of S. mutans occurred in 50 and 400 μg/mL for MPEO-CNs and unloaded-nanogel, respectively. Among biofilm synthesis genes, gtfB, gtfC, gtfD were slightly affected by MPEO-CNs treatment, while gbpB, spaP, brpA, relA, and vicR genes underwent significant down-regulation in the presence of both unloaded-nanogel and MPEO-loaded-nanogel. This study demonstrated that the MPEO-CNs promised an efficient nanoformulation with the greatest inhibitory action against some glycosyltransferase genes (gtfB, C and D) as important enzymes involved in extracellular polymers. Finally, the results concluded that MPEO-CNs have a potential use as antibiofilm agent in toothpaste or mouth washing formulations.
胡椒薄荷精油（MPEO）被载入壳聚糖纳米凝胶中，用作抗变异链球菌生物膜的抗菌剂，并保护其牙菌斑。壳聚糖纳米粒子（CsNPs）通过使用三聚磷酸酯（TPP）的连接桥的溶胶-凝胶法制备。通过傅里叶变换红外光谱（FTIR）、扫描电子显微镜/能谱（SEM/EDX）、动态光散射（DLS）和 Zeta 电位评估 MPEO-CNs 的生理特性。测定 MPEO-CNs 的释放动力学、最小抑菌浓度（MIC）和最小杀菌浓度（MBC）。在低于 MIC 的浓度下，研究了 MPEO-CNs 对生物膜相关基因（包括 grfB、C 和 D、brpA、spaP、gbpB、relA 和 vicR 共 8 个基因）表达的影响。MPEO 中最丰富的生物活性化合物是薄荷醇（45.05%）和薄荷脑（17.53%）。SEM/EDX 显示 MPEO 成功地被包封到 CsNPs 中，随后元素峰的丰度发生变化。壳聚糖谱上的 1737cm 处的信号归因于与 MPEO 掺入重叠的羧酸（CO）基团。2361cm 处的新信号归因于壳聚糖中胺基团与 TPP 中的磷酸单元之间的静电相互作用，TPP 是 MPEO-壳聚糖的组成部分。MPEO 掺入多孔纳米凝胶会降低纳米颗粒的单分散性，从而提高 Z 平均值。在环境温度下，在水醇溶剂中 360 小时内，MPEO 的最大释放量约为 50%。与未加载壳聚糖纳米凝胶相比，细菌细胞的粘附对 MPEO 的纳米制剂表现出高度的敏感性。MPEO-CNs 和未加载纳米凝胶对 S. mutans 的抗生物膜抑制作用分别为 50 和 400μg/mL。在生物膜合成基因中，gtfB、gtfC 和 gtfD 基因受 MPEO-CNs 处理的影响较小，而 gbpB、spaP、brpA、relA 和 vicR 基因在未加载纳米凝胶和加载 MPEO 的纳米凝胶存在下均显著下调。这项研究表明，MPEO-CNs 有望成为一种高效的纳米制剂，对参与细胞外聚合物的一些糖基转移酶基因（gtfB、C 和 D）具有最大的抑制作用。最后，结果表明 MPEO-CNs 具有作为牙膏或漱口剂配方中抗生物膜剂的潜力。
