【摘要】 目的探讨4种不同类型光敏剂:亚甲基二甲基蓝(9-dimethylmethylene blue,DMMB)、菌绿素38(Bacteriochlorins 38,BC38)、玫瑰红(Rose Bengal,RB)和尼罗蓝衍生物(5-Ethylamino-9-diethylminobenzo[a]phenothiazinium chlorin,EtNBS),分别介导的光动力抗菌疗法(antimicrobial photodynamic therapy,APDT)对白色念珠菌的体外杀菌效果。方法以白色念珠菌标准株DAY 286为实验对象,将实验分为4大组:光动力治疗组(APDT组)、单纯光敏剂对照组、单纯光照组及空白对照组。(1)APDT组:根据光敏剂种类不同分为4小组,DMMB组、BC38组、RB组和EtNBS组。不同浓度的各组光敏剂1ml分别与10~7菌落数/ml白色念珠菌1 ml混合,避光孵育30 min后,DMMB组和EtNBS组选取波长660 nm光源照射;BC38组选取波长730 nm光源照射;RB组选择波长540 nm光源照射,每组照射光剂量能量密度均为10 J/cm~2。(2)单纯光敏剂对照组:分组方式与APDT组相同,各种不同类型光敏剂与菌悬液混合,避光孵育30 min后,不予任何光照。(3)单纯光照组:无光敏剂,菌液避光孵育30 min后,予APDT组相同条件光源照射。(4)空白对照组:无光敏剂,不予任何光照。实验后的菌悬液经连续梯度稀释接种于培养基,孵育24～36 h,进行菌落计数。结果在能量密度10 J/cm~2条件下,各光敏药物的浓度分别为DMMB为10μM;BC38为5μM;RB为50μM;EtNBS为10μM,均清除了99. 99%白色念珠菌。当光敏剂浓度为5μM,光能量密度为10 J/cm~2时,DMMB、BC38、RB、EtNBS介导的APDT使真菌存活率分别下降99. 992%、99. 999%、3. 5%和99. 980%。除APDT组外,其余两组白色念珠菌存活率无明显下降,与空白对照组比较,差异无统计学意义(P>0. 05)。结论光能量密度一定时,APDT效果随光敏剂浓度增加而增强。相同光敏剂浓度及光能量密度条件下,DMMB、EtNBS及BC38对白色念珠菌的APDT效果优于RB。更多还原

【Abstract】 Objective To evaluate the in vitro effect of the antimicrobial photodynamic therapy(APDT)relying on four different photosensitizers(PSs)on standard suspension of candida albicans(C. albicans).Methods Four different PSs, namely, 1,9-dimethylmethylene blue(DMMB), 5-(Ethylamino)-9-diethylminobenzo[a]phenothiazinium chlorin(Et NBS),Rose Bengal(RB)and Bacteriochlorins 38(BC38),were used in this vitro study. C. albicans standard strain DAY286 was prepared to form a concentration of 107 colony forming unit(CFU)/ml. The experiments were conducted to 4 groups. As to the APDT groups,different concentrations of PSs such as DMMB,RB,Et NBS and BC38 were respectively mixed with fungi and incubated in dark for 30 min. Then the suspension was illuminated with light of different wavelengths with same radiant exposure of 10 J/cm~2. For the photosensitizer groups,different PSs(DMMB,RB,Et NBS and BC38)were incubated with fungi for 30 min without illumination. For the light groups,the fungi were only exposed to the same light adopted by the APDT group. For the blank control groups,neither light nor PS was given to the fungi suspension. The survival fraction of C. albicans after treatment was evaluated by counting CFU.Results At an illumination exposure of 10 J/cm~2,99. 99% of C. albicans were eliminated by APDT respectively mediated with DMMB(10 μM),BC38(5 μM),RB(50 μM),and Et NBS(10 μM). Different PSs showed distinct APDT effects against C.albicans,and DMMB,BC38,RB and Et NBS-mediated APDT decreased the fungal survival fraction by 99. 992%,99. 999%,3. 5% and 99. 980% respectively at a concentration of 5 μM and an irradiance of 10 J/cm~2. No difference existed among the light groups,photosensitizer groups and blank control groups(P>0. 05).Conclusions Within a fixed radiant exposure,the effect of APDT individually mediated with DMMB,Et NBS,RB and BC38 is enhanced with the increase of the concentration of the photosensitizer used. Given the same concentration and illuminated exposure,the APDT respectively mediated with DMMB,Et NBS and BC38 was more efficient to eliminate C. albicans than that with RB.更多还原