Vascular-targeted photodynamic therapy (V-PDT) is an effective treatment for port wine stains (PWS). However, repeated treatment is usually needed to achieve optimal treatment outcomes, possibly due to the limited treatment light penetration depth in the PWS lesion. The optical clearing technique can increase light penetration in depth by reducing light scattering. This study aimed to investigate the V-PDT in combination with an optical clearing agent (OCA) for the therapeutic enhancement of V-PDT in the rodent skinfold window chamber model. Vascular responses were closely monitored with laser speckle contrast imaging (LSCI), optical coherence tomography angiography, and stereo microscope before, during, and after the treatment. We further quantitatively demonstrated the effects of V-PDT in combination with OCA on the blood flow and blood vessel size of skin microvasculature. The combination of OCA and V-PDT resulted in significant vascular damage, including vasoconstriction and the reduction of blood flow. Our results indicate the promising potential of OCA for enhancing V-PDT for treating vascular-related diseases, including PWS.

研究了经三种不同类型的透明剂处理后的在体人皮组织在波长为400～1 000 nm范围内随时间变化反射光谱特性的变化及各组于580 nm处分别在0～60 min时间段各组反射光谱的改变程度。 实验采用USB-4000光纤光谱仪分别获取经丙三醇、 葡萄糖及丙二醇处理在体人皮肤组织前后的在0, 10, 20, 30, 40, 50和60 min的平均漫反射光谱。 实验结果表明: 分别经三种不同类型透明处理后的皮肤组织的平均反射光强度都呈现出明显的减弱， 但是随着各自作用于皮肤组织时间的增长， 所导致的相对反射率减少量逐渐增大。 经40%甘油作用于皮肤组织后在10, 20, 30, 40， 50和60 min处的相对反射率的减少分别为5%, 7%, 9%, 10%, 11%和12%， 经40%葡萄糖作用于皮肤组织后在10, 20, 30, 40, 50和 60 min处的相对反射率的减少分别为9%, 13%, 16%, 19%, 21%和22%， 而40%丙二醇作用于皮肤组织后在10, 20, 30, 40, 50和60 min处的相对反射率的减少分别为14%, 22%, 29%, 32%, 34%和35%。 可见， 这三种不同类型的透明剂都能够显著增强光在皮肤组织中的穿透能力， 在0～60 min的时间内各组得光透明时间进程也有所不同， 在同体积分数下， 光学透明效果差异显著地由高到低依次为40%丙二醇， 40%葡萄糖， 40%甘油。

In order to enhance the optical clearing effect of topically applied optical clearing agents (OCAs), we evaluated the effect of propylene glycol (PG) as a chemical penetration enhancer (PE) on optical clearing of skin in vitro by observation and measurement of optical-transmittance and diffuse-reflectance spectra. Three OCAs, i.e., glycerol, D-sorbitol and PEG400, and two other penetration enhancers, Azone and Thiazone, were used in this study. The results indicated that the decrease of reduced scattering coefficient caused by OCA/PG was larger than that by pure OCA, and the change by OCA/water was the least after the same treatment time. There were significant differences for the reduced scattering coefficient at 630 nm after 120 min application of agents between OCA and OCA/PG. The efficacy of optical clearing caused by OCA/PG depended on the OCA itself. When PEG400 was mixed with three different PEs, we found the optical clearing were different. The penetration enhancing ability of PG was much better compared to Azone, and suboptimal to Thiazone. Also, this study provides evidence for the use of PG as a PE in order to improve skin optical clearing.

研究一种新型促渗剂——噻酮对皮肤组织光透明效果的影响。分别用单纯聚乙二醇400(PEG400)溶液以及PEG400与噻酮的混合溶液作用于含角质层及去角质层的离体乳猪皮肤, 利用积分球系统动态检测样品对632.8 nm光的透射率变化, 并对样品拍照获得直观图。结果表明：混合溶液作用于两种皮肤模型后, 其光透明性均有不同程度的增加, 即衰减系数降低;比较去角质层皮肤与含角质层皮肤的衰减系数的变化, 前者比后者大19倍;单纯的PEG400仅对去角质皮肤有一定的光透明效果, 并且所导致的皮肤衰减系数的降低仅为混合液作用后的2/3。因此, 噻酮作为良好的促渗剂能与PEG400产生协同效应, 有效提高皮肤光透明效果。