Kosarieh Emad, Sattari Khavas Sahar, Hirjak Dusan, Chiniforush Nasim, Afrasiabi Shima
Department of Stomatology and Maxillofacial Surgery, Faculty of Medicine, Comenius University, Bratislava, Slovakia.
Dentofacial Deformities Research Center, Research Institute for Dental Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Lasers Med Sci. 2025 May 13;40(1):224. doi: 10.1007/s10103-025-04479-8.
For higher photodynamic efficiency, much more knowledge about the importance of the multiple parameters is required. In this in vitro study, optimized parameters (dose, light intensity, and irradiation time) were defined for the effect of phycocyanin (PC) concentrations (sub-minimum inhibitory concentrations (sub-MIC) ) activated with a 635 nm diode laser to reduce the Streptococcus mutans biofilms. Two power densities, 0.2 and 1 W/cm, were compared at different irradiation times, resulting in light energy doses of 12-60 J/cm. The light source was a diode laser (wavelength = 635 nm) and a set output power of 100 and 500 mW. After the treatments, the biofilms were analyzed based on the log colony forming units/milliliter of S. mutans. A significant biofilm reduction occurred at all evaluated fluences and concentrations except the 1/8 MIC concentration of PC compared to the control. An increase in PC concentration and power density together was associated with a greater biofilm reduction. Antimicrobial photodynamic therapy (aPDT) was more efficient against S. mutans biofilm cells at a ½ MIC concentration of PC, a power density of 1 W/cm and 60 J/cm energy dose (2 log reduction). The energy dose should not be evaluated in isolation to compare the photoinactivation effects on S. mutans biofilms. In addition, the appropriate duration of light exposure and photosensitization concentration should not be disregarded. These characteristics will contribute to the success of aPDT in the future.
为了获得更高的光动力效率，需要更多关于多个参数重要性的知识。在这项体外研究中，针对用635nm二极管激光激活的藻蓝蛋白（PC）浓度（亚最小抑菌浓度（sub-MIC））对变形链球菌生物膜的影响，定义了优化参数（剂量、光强度和照射时间）。在不同照射时间下比较了0.2和1W/cm两种功率密度，得到的光能剂量为12-60J/cm。光源为二极管激光（波长=635nm），设定输出功率为100和500mW。处理后，基于每毫升变形链球菌的对数菌落形成单位对生物膜进行分析。与对照组相比，除PC的1/8 MIC浓度外，在所有评估的光通量和浓度下生物膜均显著减少。PC浓度和功率密度的共同增加与更大程度的生物膜减少相关。在PC的1/2 MIC浓度、1W/cm的功率密度和60J/cm的能量剂量下，抗菌光动力疗法（aPDT）对变形链球菌生物膜细胞更有效（减少2个对数）。不应孤立地评估能量剂量以比较对变形链球菌生物膜的光灭活效果。此外，适当的光照持续时间和光敏剂浓度也不应被忽视。这些特性将有助于未来aPDT的成功。
