Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh, 11433, Saudi Arabia.
Dental Biomaterials Department, College of Dentistry, King Saud University, Riyadh, 11433, Saudi Arabia.
Photodiagnosis Photodyn Ther. 2023 Sep;43:103692. doi: 10.1016/j.pdpdt.2023.103692. Epub 2023 Jul 6.
This in-vitro investigation aimed to assess the antibacterial effectiveness of photo-sonodynamic treatment using methylene blue (MTB)-incorporated poly(D, L-Lactide-Co-Glycolide) acid (PLGA)-nanoparticles for the disinfection of root canals.
The synthesis of PLGA nanoparticles was achieved using a solvent displacement technique. The morphological and spectral characterization of the formulated PLGA nanoparticles were carried out using scanning electron microscopy (SEM) and Transformed-Fourier infrared spectroscopy (TFIR), respectively. One hundred human premolar teeth were sterilized and then their root canals were infected with Enterococcus faecalis (E. faecalis). Later, the bacterial viability evaluation of the following 5 research groups was conducted: (a) G-1: specimens treated with a diode laser; (b) G-2: specimens treated with antimicrobial photodynamic therapy (aPDT) and 50 µg/mL of MTB-incorporated PLGA nanoparticles; (c) G-3: specimens treated with ultrasound (US); (d) G-4: specimens treated with US and 50 µg/mL of MTB-incorporated PLGA nanoparticles; and (e) G-5: control group consisting of specimens that did not undergo any treatment.
Under SEM, the nanoparticles exhibited a uniform spherical shape and were around 100 nm. The formulated nanoparticles' size was validated through zeta potential analysis utilizing dynamic light scattering (DLS). The TFIR images of both PLGA nanoparticles and MTB-incorporated PLGA nanoparticles exhibited absorption bands ranging from around 1000 to 1200/cm and nearly from 1500 to 1750/cm. The G-5 samples (control group) demonstrated the greatest viability against E. faecalis, followed by G-3 (US-conditions specimens), G-1 (diode laser-conditioned specimens), G-2 (aPDT + MTB-incorporated PLGA-nanoparticles-conditioned specimens), and G-5 (US + MTB-incorporated PLGA-nanoparticles-conditioned specimens). Significant statistical differences (p < 0.05) were observed among all research groups, including both the experimental groups and control group.
The combination of US via MTB-incorporated PLGA nanoparticles exhibited the most effective eradication of E. faecalis, suggestive of a promising therapeutic modality against E. faecalis for disinfecting root canals with complex and challenging anatomy.
本体外研究旨在评估使用甲烯蓝（MTB）负载的聚（D，L-乳酸-共-乙醇酸）酸（PLGA）纳米粒子进行光声动力学治疗对根管消毒的抗菌效果。
通过溶剂置换技术合成 PLGA 纳米粒子。使用扫描电子显微镜（SEM）和变换傅里叶红外光谱（TFIR）分别对所制备的 PLGA 纳米粒子进行形态和光谱特征描述。将 100 颗人前磨牙进行消毒，然后将其根管感染粪肠球菌（E. faecalis）。之后，对以下 5 个研究组的细菌活力评估进行：（a）G-1：二极管激光处理的标本；（b）G-2：用抗菌光动力疗法（aPDT）和 50μg/mL MTB 负载的 PLGA 纳米粒子处理的标本；（c）G-3：超声（US）处理的标本；（d）G-4：用 US 和 50μg/mL MTB 负载的 PLGA 纳米粒子处理的标本；和（e）G-5：未经任何处理的标本组成的对照组。
在 SEM 下，纳米粒子呈现均匀的球形，直径约为 100nm。通过动态光散射（DLS）利用动势分析法对所制备的纳米粒子的大小进行验证。PLGA 纳米粒子和 MTB 负载的 PLGA 纳米粒子的 TFIR 图像均显示出约 1000 至 1200/cm 和 1500 至 1750/cm 附近的吸收带。G-5 样品（对照组）对粪肠球菌的活力最高，其次是 G-3（US 条件下的标本）、G-1（二极管激光条件下的标本）、G-2（aPDT+MTB 负载的 PLGA-纳米粒子条件下的标本）和 G-5（US+MTB 负载的 PLGA-纳米粒子条件下的标本）。所有研究组之间均存在显著的统计学差异（p<0.05），包括实验组和对照组。
通过 MTB 负载的 PLGA 纳米粒子的 US 联合使用对粪肠球菌的清除效果最有效，提示针对根管复杂且具有挑战性的解剖结构的粪肠球菌具有有前景的治疗方式。
