Division of Clinical Dentistry, School of Dentistry, International Medical University, Kuala Lumpur 57000, Malaysia.
School of Medicine, International Medical University, Kuala Lumpur 57000, Malaysia.
Molecules. 2021 Jan 30;26(3):715. doi: 10.3390/molecules26030715.
To determine the antibacterial effect of propolis nanoparticles (PNs) as an endodontic irrigant against biofilm inside the endodontic root canal system. Two-hundred-ten extracted human teeth were sectioned to obtain 6 mm of the middle third of the root. The root canal was enlarged to an internal diameter of 0.9 mm. The specimens were inoculated with for 21 days. Following this, specimens were randomly divided into seven groups, with 30 dentinal blocks in each group including: group I-saline; group II-propolis 100 µg/mL; group III-propolis 300 µg/mL; group IV-propolis nanoparticle 100 µg/mL; group V-propolis nanoparticle 300µg/mL; group VI-6% sodium hypochlorite; group VII-2% chlorhexidine. Dentin shavings were collected at 200 and 400 μm depths, and total numbers of CFUs were determined at the end of one, five, and ten minutes. The non-parametric Kruskal-Wallis and Mann-Whitney tests were used to compare the differences in reduction in CFUs between all groups, and probability values of < 0.05 were set as the reference for statistically significant results. The antibacterial effect of PNs as an endodontic irrigant was also assessed against isolates from patients with failed root canal treatment. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were also performed after exposure to PNs. A Raman spectroscope, equipped with a Leica microscope and lenses with curve-fitting Raman software, was used for analysis. The molecular interactions between bioactive compounds of propolis (Pinocembrin, Kaempferol, and Quercetin) and the proteins Sortase A and β-galactosidase were also understood by computational molecular docking studies. PN300 was significantly more effective in reducing CFUs compared to all other groups ( < 0.05) except 6% NaOCl and 2% CHX ( > 0.05) at all time intervals and both depths. At five minutes, 6% NaOCl and 2% CHX were the most effective in reducing CFUs ( < 0.05). However, no significant difference was found between PN300, 6% NaOCl, and 2% CHX at 10 min ( > 0.05). SEM images also showed the maximum reduction in with PN300, 6% NaOCl, and 2% CHX at five and ten minutes. CLSM images showed the number of dead cells in dentin were highest with PN300 compared to PN100 and saline. There was a reduction in the 484 cm band and an increase in the 870 cm band in the PN300 group. The detailed observations of the docking poses of bioactive compounds and their interactions with key residues of the binding site in all the three docking protocols revealed that the interactions were consistent with reasonable docking and IFD docking scores. PN300 was equally as effective as 6% NaOCl and 2% CHX in reducing the biofilms.
为了确定蜂胶纳米粒子（PNs）作为根管冲洗剂对内根管系统生物膜的抗菌效果。将 210 颗人牙切成 6 毫米的中段。根管扩大至内径 0.9 毫米。将标本接种 ，培养 21 天。此后，将标本随机分为七组，每组 30 个牙本质块，包括：I 组-生理盐水；II 组-蜂胶 100μg/mL；III 组-蜂胶 300μg/mL；IV 组-蜂胶纳米粒子 100μg/mL；V 组-蜂胶纳米粒子 300μg/mL；VI 组-6%次氯酸钠；VII 组-2%洗必泰。在 200 和 400μm 深度采集牙本质屑，在第 1、5 和 10 分钟结束时确定总 CFU 数。使用非参数 Kruskal-Wallis 和 Mann-Whitney 检验比较所有组之间 CFU 减少的差异，概率值 < 0.05 被设为统计学显著结果的参考值。还评估了 PNs 作为根管冲洗剂对来自根管治疗失败患者的 分离株的抗菌作用。暴露于 PNs 后还进行了扫描电子显微镜（SEM）和共聚焦激光扫描显微镜（CLSM）检查。配备 Leica 显微镜和带有曲线拟合拉曼软件的透镜的拉曼光谱仪用于分析。还通过计算分子对接研究了解了蜂胶（Pinocembrin、Kaempferol 和 Quercetin）生物活性化合物与 Sortase A 和β-半乳糖苷酶之间的分子相互作用。在所有时间间隔和两个深度，PN300 与所有其他组相比（ < 0.05），除了 6% NaOCl 和 2% CHX（ > 0.05），在减少 CFU 方面更有效。在 5 分钟时，6% NaOCl 和 2% CHX 是减少 CFU 最有效的（ < 0.05）。然而，在 10 分钟时，PN300、6% NaOCl 和 2% CHX 之间没有发现显著差异（ > 0.05）。SEM 图像还显示，在 5 分钟和 10 分钟时，PN300、6% NaOCl 和 2% CHX 对 的减少最多。CLSM 图像显示，与 PN100 和生理盐水相比，PN300 处理的牙本质中死亡细胞数量最多。PN300 组中 484cm 波段减少，870cm 波段增加。在所有三个对接方案中，生物活性化合物的对接构象的详细观察及其与所有三个对接方案中结合位点关键残基的相互作用表明，相互作用与合理的对接和 IFD 对接评分一致。PN300 在减少 生物膜方面与 6% NaOCl 和 2% CHX 同样有效。
