Department of Ophthalmology and Visual Science, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-Ku, Hiroshima, 734-8551, Japan.
Department of Ophthalmology, Hiroshima Prefectural Hospital, 1-5-54 Ujinakanda, Minami-Ku, Hiroshima, 734-8530, Japan.
Lasers Med Sci. 2024 Jun 5;39(1):151. doi: 10.1007/s10103-024-04103-1.
The aim of this study was to compare two types of light irradiation devices for antimicrobial photodynamic therapy (aPDT). A 660-nm light-emitting diode (LED) and a 665-nm laser diode (LD) were used for light irradiation, and 0.1 mg/L TONS 504, a cationic chlorin derivative, was used as the photosensitizer. We evaluated the light attenuation along the vertical and horizontal directions, temperature rise following light irradiation, and aPDT efficacy against Staphylococcus aureus under different conditions: TONS 504 only, light irradiation only, and TONS 504 with either LED (30 J/cm) or LD light irradiation (continuous: 30 J/cm; pulsed: 20 J/cm at 2/3 duty cycle, 10 J/cm at 1/3 duty cycle). Both LED and LD light intensities were inversely proportional to the square of the vertical distance from the irradiated area. Along the horizontal distance from the nadir of the light source, the LED light intensity attenuated according to the cosine quadrature law, while the LD light intensity did not attenuate within the measurable range. Following light irradiation, the temperature rise increased as the TONS 504 concentration increased in the order of pulsed LD < continuous LD < LED irradiation. aPDT with light irradiation only or TONS 504 only had no antimicrobial effect, while aPDT with TONS 504 under continuous or pulsed LD light irradiation provided approximately 3 log reduction at 30 J/cm and 20 J/cm and approximately 2 log reduction at 10 J/cm. TONS 504-aPDT under pulsed LD light irradiation provided anti-microbial effect without significant temperature rise.
本研究旨在比较两种用于抗菌光动力疗法（aPDT）的光照射设备。使用 660nm 发光二极管（LED）和 665nm 激光二极管（LD）进行光照射，0.1mg/L 的 TONS 504（一种阳离子卟啉衍生物）用作光敏剂。我们评估了在不同条件下沿垂直和水平方向的光衰减、光照射后的温升以及 TONS 504 对抗金黄色葡萄球菌的 aPDT 效果：仅 TONS 504、仅光照射以及 TONS 504 联合 LED（30J/cm）或 LD 光照射（连续：30J/cm；脉冲：2/3 占空比时为 20J/cm，1/3 占空比时为 10J/cm）。LED 和 LD 的光强度均与距照射区域的垂直距离的平方成反比。沿光源最低点的水平距离，LED 光强度根据余弦平方律衰减，而 LD 光强度在可测量范围内没有衰减。光照射后，随着 TONS 504 浓度的增加，温度升高，脉冲 LD＜连续 LD＜LED 照射。仅光照射或 TONS 504 单独照射均无抗菌作用，而 TONS 504 联合连续或脉冲 LD 光照射在 30J/cm 和 20J/cm 时提供约 3 对数减少，在 10J/cm 时提供约 2 对数减少。脉冲 LD 光照射下的 TONS 504-aPDT 提供了抗菌作用，而没有明显的温升。
