Uekubo Ayano, Hiratsuka Koichi, Aoki Akira, Takeuchi Yasuo, Abiko Yoshimitsu, Izumi Yuichi
Department of Periodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
Department of Biochemistry and Molecular Biology, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
Laser Ther. 2016 Dec 30;25(4):299-308. doi: 10.5978/islsm.16-OR-25.
A combination of rose bengal (RB) and blue LED (BL) has emerged as a new technical modality for antimicrobial photodynamic therapy (a-PDT). The purpose of this study was to clarify the influence of oxygen on the antimicrobial effect of RB + BL treatment on cells were treated with RB, BL (450-470 nm; 1 W/cm, 5 s), or RB + BL under anaerobic/aerobic conditions. Cells were incubated anaerobically, and the cell density (OD) was measured after 6-48 h. Additionally, cells were cultured anaerobically on blood agar plates for 9 days, and the resulting colonies were observed. Bacterial growth within 1 h of aerobic RB + BL treatment was examined, and RNA degradation due to anaerobic/aerobic RB + BL treatment was measured after 3 h of culture. Under anaerobic conditions, RB + BL significantly suppressed bacterial growth after 18 h; however, the growth after 48 h and the number of colonies after 9 days were similar to those of the untreated control. RNA degradation in the anaerobic-treatment group was not significantly different from that in the control. Under aerobic conditions, RB + BL immediately affected bacterial growth and completely inhibited growth for up to 48 h. Few colonies were detected even after 9 days of culture, and RNA was completely degraded. Unlike the bacteriostatic effect of anaerobic treatment, aerobic RB + BL treatment may have a bactericidal action via a-PDT effect, resulting in the destruction of RNA and bacterial cells within a short period.
孟加拉玫瑰红（RB）与蓝色发光二极管（BL）的组合已成为抗菌光动力疗法（a-PDT）的一种新技术模式。本研究的目的是阐明氧气对RB + BL处理抗菌效果的影响。在厌氧/好氧条件下，用RB、BL（450 - 470 nm；1 W/cm²，5 s）或RB + BL处理细胞。细胞在厌氧条件下孵育，6 - 48小时后测量细胞密度（OD）。此外，细胞在血琼脂平板上厌氧培养9天，观察所得菌落。检测好氧RB + BL处理1小时内的细菌生长情况，并在培养3小时后测量厌氧/好氧RB + BL处理导致的RNA降解。在厌氧条件下，RB + BL在18小时后显著抑制细菌生长；然而，48小时后的生长情况以及9天后的菌落数量与未处理的对照组相似。厌氧处理组的RNA降解与对照组无显著差异。在好氧条件下，RB + BL立即影响细菌生长，并在长达48小时内完全抑制生长。即使培养9天后也几乎检测不到菌落，且RNA完全降解。与厌氧处理的抑菌作用不同，好氧RB + BL处理可能通过a-PDT效应产生杀菌作用，从而在短时间内破坏RNA和细菌细胞。
