Kranz Stefan, Huebsch Marie, Guellmar Andre, Voelpel Andrea, Tonndorf-Martini Silke, Sigusch Bernd W
Polyclinic for Conservative Dentistry and Periodontology, University Hospital Jena, An der alten Post 4, Jena, 07743, Germany.
Lasers Surg Med. 2015 Apr;47(4):350-60. doi: 10.1002/lsm.22336. Epub 2015 Mar 8.
It has been shown that certain vitamins can significantly enhance the effect of photodynamic anti-tumor therapy. Unfortunately, there is no sufficient information available about the impact of those antioxidants on antimicrobial Photodynamic Therapy (aPDT). The present study is aimed at investigating the antimicrobial effect of the dye indocyanine green (ICG) in the presence of Trolox(TM) , a vitamin E analogue, upon irradiation with near-infrared (NIR) laser light (808 nm) on the gramnegative periodontopathogenic bacteria Aggregatibacter actinomycetemcomitans (A.a.), Porphyromonas gingivalis (P.g.) and Fusobacterium nucleatum (F.n.).
Bacteria solved in PBS were incubated with ICG (50-500 μg/ml) in the presence and absence of Trolox(TM) (2 mM). Irradiation was performed after 10 minutes of dark-incubation with NIR-laser-light (25-100 J/cm(2) , 810 nm). During treatment, temperature was also recorded inside the bacterial solutions. The treated suspensions were serial diluted and plated onto blood agar plates. After anaerobe cultivation for 5 days the colony-forming units (CFU/ml) were determined.
The antibacterial effect was ICG-concentration and exposure dependent. It was found that high ICG-concentrations and light fluence rates caused bacterial reduction due to hyperthermia. Where low ICG-concentrations (<250 μg/ml) and fluence rates only induced minor regression, additional Trolox(TM) -administration significantly enhanced the photodynamic effect. While treatment of A.a. (250 μg/ml ICG, 100 J/cm(2) ) without Trolox(TM) caused no bacterial reduction, additional administration led to total eradication. In the presence of Trolox(TM) reduction to one-fifth of the original ICG-concentration (50 μg/ml) still induced total suppression of P.g. and F.n. at identical fluence (100 J/cm(2) ). Treatment with ICG, NIR-light or Trolox(TM) alone showed no remarkable bactericidal effect. Application of high ICG-concentrations (500 μg/ml) and exposure values (100 J/cm(2) ) caused peak temperatures of 64.53°C.
The results clearly show that Trolox(TM) significantly enhanced the antibacterial effect of ICG upon irradiation with NIR-laser-light. Additional administration of Trolox(TM) may also increase the efficiency of other aPDT systems.
已表明某些维生素可显著增强光动力抗肿瘤治疗的效果。遗憾的是，关于这些抗氧化剂对抗菌光动力疗法（aPDT）的影响尚无足够信息。本研究旨在探讨在维生素E类似物生育三烯酚（Trolox™）存在的情况下，染料吲哚菁绿（ICG）在近红外（NIR）激光（808 nm）照射下对革兰氏阴性牙周病原菌伴放线聚集杆菌（A.a.）、牙龈卟啉单胞菌（P.g.）和具核梭杆菌（F.n.）的抗菌作用。
将溶解于磷酸盐缓冲液（PBS）中的细菌在有和没有生育三烯酚（Trolox™，2 mM）的情况下与ICG（50 - 500 μg/ml）一起孵育。在黑暗孵育10分钟后用近红外激光（25 - 100 J/cm²，810 nm）进行照射。在处理过程中，还记录细菌溶液内部的温度。将处理后的悬浮液进行系列稀释并接种到血琼脂平板上。在厌氧培养5天后测定菌落形成单位（CFU/ml）。
抗菌效果取决于ICG浓度和照射量。发现高ICG浓度和光通量率由于热疗导致细菌减少。当低ICG浓度（<250 μg/ml）和通量率仅引起轻微减少时，额外给予生育三烯酚（Trolox™）可显著增强光动力效应。在没有生育三烯酚（Trolox™）的情况下，用ICG（250 μg/ml）和100 J/cm²处理A.a.不会导致细菌减少，额外给予则导致完全根除。在生育三烯酚（Trolox™）存在的情况下，将ICG浓度降至原始浓度的五分之一（50 μg/ml）在相同通量（100 J/cm²）下仍能完全抑制P.g.和F.n.。单独用ICG、近红外光或生育三烯酚（Trolox™）处理均未显示出显著的杀菌效果。应用高ICG浓度（500 μg/ml）和照射量值（100 J/cm²）导致峰值温度达到64.53°C。
结果清楚地表明，生育三烯酚（Trolox™）在近红外激光照射下显著增强了ICG的抗菌效果。额外给予生育三烯酚（Trolox™）也可能提高其他aPDT系统的效率。
