LED蓝光联合玫瑰红对具核梭杆菌的体外光动力灭菌研究

In Vitro Antimicrobial Effect of Photodynamic Therapy Using Blue Light and Rose-Bengal Light on Fusobacterium Nucleatumin

目的体外研究蓝光LED联合玫瑰红染料对具核梭杆菌的杀菌效果。方法实验对象具核梭杆菌标准菌株ATCC10953,实验分为三组。分别为:单独蓝光照射组(A组)、单纯玫瑰红溶液组(B组)和光动力组(C组)。A组,采用蓝色LED光固化灯照射,功率密度0.3 W/cm^2,照射时间20 s、40 s和60 s。B组,按照玫瑰红溶液的浓度0、0.016、0.16和1.6 mg/ml处理,不进行蓝光照射。C组,加入0.16 mg/ml的玫瑰红溶液后采用蓝光分别照射20 s、40 s和60 s;将葡萄糖酸氯己定的菌液作为阳性对照;生理盐水作为阴性对照。所有实验后的菌液连续稀释,选择合适稀释浓度涂布在固体培养基上,厌氧培养7 d后计算菌落数。同时,使用液体测温仪分别测量A组和C组的菌液的温度,计算照射前后温度的升高量。结果 A组单独蓝光照射20 s、40 s、60 s杀菌后菌落数减少的对数值分别为0.33、0.36、0.61。C组杀菌后菌落数减少的对数值分别为1.43、2.14、1.47。结论蓝光单独照射对具核梭杆菌的杀菌和生长抑制作用较弱,而联合玫瑰红后杀菌效果明显增强。蓝光联合玫瑰红的光动力杀菌疗法为牙周治疗提供新的思路和方法。

Objective Blue light,having favorable wavelength properties,possesses an antimicrobial effect. Blue light is more effective as a lightsource for PDT than red light. This study aims to investigate the effect of the PDT using jointly the high-power blue LED and red-dye agent on Fusobacterium nucleatum in vitro.Methods Fusobacterium nucleatum 10953 suspension was irradiated with blue LED（BL）（1. 2 w/cm^2） for 20-60 s,or mixed with rose bengal（RB） with or without BL irradiation（40 s）. F. nucleatum suspension in combination with Chlorhexidine gluconate（CHG） was employed for positive control. All the suspensions of F. nucleatum were serially diluted,plated and incubated anaerobically,and the numbers of colony-forming units（CFUs） were counted on day 7.Results BL irradiation at 20 s,40 s and 60 s resulted in a log reduction of 0. 33,0. 36 and 0. 61 respectively,in the numbers of CFUs. 0. 16 mg/ml RB with BL at 20 s,40 s and 60 s demonstrated a log reduction of 1. 43,2. 14 and 1. 47 respectively.Conclusions Within the limits of this study,blue light was found to have anantimicrobial/growth-inhibiting effect on F. nucleatum,and the PDT using jointly blue light and RB is promising as a new technical modality for bacterial elimination in periodontal therapy.