Introduction. Antimicrobial sonodynamic therapy (aSDT) is an approach that uses ultrasound waves (UWs) and a sonosensitizer to generate reactive oxygen species (ROS) to damage microbial cells in biofilms. Using nano-carriers, such as exosomes (Exos), to deliver the sonosensitizer can potentially enhance the effectiveness of aSDT. Hypothesis/Gap Statement. aSDT can downregulate the expression of gelE and sprE genes, increasing the production of endogenous ROS and degradation of pre-formed Enterococcus faecalis biofilms. Aim. This study investigated the anti-biofilm effect of aSDT-based periodontal ligament stem cell-derived exosome-loaded kojic acid (KA@PDL-Exo) on pre-formed E. faecalis biofilms in root canals. Methodology. Following the isolation and characterization of PDL-Exo, KA@PDL-Exo was prepared and confirmed. The minimal biofilm inhibitory concentration (MBIC) of KA, PDL-Exo, KA@PDL-Exo and sodium hypochlorite (NaOCl) was determined, and their anti-biofilm effects were assessed with and without UWs. The binding affinity of KA with GelE and SprE proteins was evaluated using in silico molecular docking. Additionally, the study measured the generation of endogenous ROS and evaluated changes in the gene expression levels of gelE and sprE. Results. The results revealed a dose-dependent decrease in the viability of E. faecalis cells within biofilms. KA@PDL-Exo was the most effective, with an MBIC of 62.5 µg ml−1, while NaOCl, KA and PDL-Exo had MBIC values of 125, 250 and 500 µg ml−1, respectively. The use of KA@PDL-Exo-mediated aSDT resulted in a significant reduction of the E. faecalis biofilm (3.22±0.36 log10 c.f.u. ml−1; P<0.05). The molecular docking analysis revealed docking scores of −5.3 and −5.2 kcal mol−1 for GelE-KA an SprE-KA, respectively. The findings observed the most significant reduction in gene expression of gelE and sprE in the KA@PDL-Exo group, with a decrease of 7.9- and 9.3-fold, respectively, compared to the control group (P<0.05). Conclusion. The KA@PDL-Exo-mediated aSDT was able to significantly reduce the E. faecalis load in pre-formed biofilms, decrease the expression of gelE and srpE mRNA, and increase the generation of endogenous ROS. These findings imply that KA@PDL-Exo-mediated aSDT could be a promising anti-biofilm strategy that requires additional in vitro and in vivo investigations.

中文翻译：

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基于抗菌声动力疗法的牙周膜干细胞来源的外泌体负载曲酸对粪肠球菌生物膜的抗生物膜效果评价

介绍。抗菌声动力疗法 (aSDT) 是一种使用超声波 (UW) 和声敏剂产生活性氧 (ROS) 来破坏生物膜中微生物细胞的方法。使用纳米载体，例如外泌体 (Exos)，来传递声敏剂可以潜在地增强 aSDT 的有效性。假设/差距陈述。aSDT 可以下调gelE和sprE基因的表达，增加内源性 ROS 的产生和预先形成的粪肠球菌生物膜的降解。目的。本研究调查了基于 aSDT 的牙周膜干细胞衍生的外泌体负载曲酸 (KA@PDL-Exo) 对根管中预先形成的粪肠球菌生物膜的抗生物膜作用。方法。在分离和表征 PDL-Exo 后，制备并确认了 KA@PDL-Exo。测定了 KA、PDL-Exo、KA@PDL-Exo 和次氯酸钠 (NaOCl) 的最低生物膜抑制浓度 (MBIC)，并在使用和不使用 UW 的情况下评估它们的抗生物膜效果。使用计算机分子对接评估 KA 与 GelE 和 SprE 蛋白的结合亲和力。此外，该研究还测量了内源性 ROS 的产生，并评估了gelE和sprE基因表达水平的变化。结果。结果表明，生物膜内粪肠球菌细胞的活力呈剂量依赖性下降。KA@PDL-Exo 是最有效的，MBIC 为 62.5 µg ml -1，而 NaOCl、KA 和 PDL-Exo 的 MBIC 值分别为 125、250 和 500 µg ml -1。使用KA@PDL-Exo介导的aSDT导致粪肠球菌生物膜显着减少（3.22±0.36 log 10 cfu ml -1；P <0.05）。分子对接分析显示，GelE-KA 和 SprE-KA 的对接分数分别为 -5.3 和 -5.2 kcal mol -1 。结果发现，KA@PDL-Exo 组中gelE和sprE基因表达量下降最为显着，与对照组相比，分别下降了 7.9 倍和 9.3 倍（ P <0.05）。结论。KA@PDL-Exo介导的aSDT能够显着减少预先形成的生物膜中粪肠球菌的负载，降低gelE和srpE的表达 mRNA，并增加内源性ROS的产生。这些发现表明 KA@PDL-Exo 介导的 aSDT 可能是一种有前途的抗生物膜策略，需要额外的体外和体内研究。