Papayan Garry V, Podoplekina Natalya D, Glagoleva Ekaterina N, Petrishchev Nikolay N, Galagudza Michael M
Laser Medicine Centre, Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russian Federation; Institute of Experimental Medicine, Almazov National Medical Research Centre, Akkuratova str. 2, Saint Petersburg 197341, Russian Federation.
Laser Medicine Centre, Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russian Federation; Aesthetic Medical Clinic "Come Mode Medical", Saint Petersburg, Russian Federation.
Photodiagnosis Photodyn Ther. 2024 Feb;45:103948. doi: 10.1016/j.pdpdt.2023.103948. Epub 2023 Dec 23.
The method of photodynamic therapy for skin rejuvenation (PDT-SR) provides an improvement in appearance with a safe and painless effect. The quality of treatment is most often assessed subjectively. The most informative morphological control methods are rarely used due to the invasiveness of the sampling procedure.
This study aimed to find out the possibility of using skin autofluorescence spectroscopy (SAF) for an objective assessment of changes occurring in the skin during PDT-SR.
This study included 12 volunteers (10 women, 2 men) aged 32 to 79 years. Two (n = 6) or three (n = 6) PDT sessions were performed at intervals of 13-30 days. Photosensitizer chlorin e6, exposure 20 min, energy density 18-24 J/cm were used. SAF spectra were recorded using a two-wavelength fiber optic spectrometer under excitation at wavelengths (λ) of 365 nm and 440 nm. Measurements were made both before and after each PDT session and up to 25-238 days from the start of treatment. For the evaluation, we used the spectra AF365(λ) and AF440(λ) averaged over 40 points corrected for diffuse reflection at λ=440 nm in the range λ= 460-700 nm, as well as the spectra of the ratios AFN365(λ) and AFN440(λ), which were obtained by dividing the intensities of the current spectra by the intensities collected before PDT-SR.
PDT-SR led to changes in both the intensity and shape of the spectra. Analysis of the spectra using numerical fitting of the spectra showed that the main changes can be explained by changes in the content of advanced glycation end products (AGEs), as well as lipofuscin-like lipopigments (LPs) and porphyrins (PPs). The spectra of AGEs upon excitation at wavelengths of 365 and 440 nm differ, which may be due to the formation of two types of bonds, with collagen and elastin. By the end of the study, the vast majority of the examined volunteers showed a significant decrease of the parameters characterizing both of these types of AGEs, AGE365 (0.56-1.2) and AGE440 (0.58-1.01), relative to the beginning of the study. In most cases, a decrease was also noted for LPs and PPs. AGE365 and AGE440 were positively correlated with the age of the volunteers (r = 0.26-0.46 %). A steady decrease in the content of AGEs occurred approximately on the 40th day.
SAF spectroscopy makes it possible to assess changes in the content of AGEs, LPs, and PPs in the skin during PDT-SR. The method has great potential for non-invasive monitoring of the treatment process, as well as its improvement, including through its personalization. In addition, the method can be used to study the mechanisms of age-related skin changes at the molecular level and to study the processes of rejuvenation.
光动力疗法用于皮肤年轻化（PDT-SR）的方法能在安全无痛的情况下改善外观。治疗质量大多通过主观评估。由于取样过程具有侵入性，最具信息量的形态学控制方法很少被使用。
本研究旨在探究使用皮肤自体荧光光谱法（SAF）客观评估PDT-SR过程中皮肤发生变化的可能性。
本研究纳入了12名年龄在32至79岁之间的志愿者（10名女性，2名男性）。每隔13 - 30天进行两次（n = 6）或三次（n = 6）PDT治疗。使用光敏剂氯e6，照射20分钟，能量密度为18 - 24 J/cm。使用双波长光纤光谱仪在365 nm和440 nm波长的激发下记录SAF光谱。在每次PDT治疗前后以及治疗开始后25 - 238天内进行测量。为了评估，我们使用了在460 - 700 nm范围内对λ = 440 nm处的漫反射进行校正的40个点平均后的光谱AF365(λ)和AF440(λ)，以及通过将当前光谱强度除以PDT-SR之前收集的强度而获得的比率光谱AFN365(λ)和AFN440(λ)。
PDT-SR导致光谱强度和形状发生变化。通过对光谱进行数值拟合分析表明，主要变化可以用晚期糖基化终产物（AGEs）、脂褐素样脂色素（LPs）和卟啉（PPs）含量的变化来解释。在365 nm和440 nm波长激发下AGEs的光谱不同，这可能是由于与胶原蛋白和弹性蛋白形成了两种类型的键。到研究结束时，绝大多数接受检查的志愿者相对于研究开始时，表征这两种类型AGEs的参数AGE365（0.56 - 1.2）和AGE440（0.58 - 1.01）显著降低。在大多数情况下，LPs和PPs也有所降低。AGE365和AGE440与志愿者年龄呈正相关（r = 0.26 - 0.46%）。AGEs含量大约在第40天开始稳步下降。
SAF光谱法能够评估PDT-SR过程中皮肤中AGEs、LPs和PPs含量的变化。该方法在无创监测治疗过程及其改进方面具有巨大潜力，包括通过个性化实现。此外，该方法可用于在分子水平研究与年龄相关的皮肤变化机制以及年轻化过程。
