Liu Caihua, Zhi Zhongwei, Tuchin Valery V, Luo Qingming, Zhu Dan
Wuhan National Laboratory for Optoelectronics, Britton Chance Center for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan 430074, China.
Lasers Surg Med. 2010 Feb;42(2):132-40. doi: 10.1002/lsm.20900.
Tissue optical clearing technique based on immersion of tissues into optical clearing agents (OCAs) can reduce the scattering and enhance the penetration of light in tissue. However, the barrier function of epidermis limits the penetration of OCAs, and hence is responsible for the poor optical clearing efficacy of skin by topical action. In this study, a variety of light irradiation was applied to increase permeability of agents in skin and improve the optical clearing efficacy.
STUDY DESIGN/MATERIALS AND METHODS: Different light sources with different dose, i.e, CO(2) laser, Nd:YAG laser (532 and 1,064 nm) with different pulse modes and Intense Pulsed Light (IPL) (400-700 and 560-950 nm) were used to irradiate rat skin in vivo, and then glycerol was applied onto the irradiated zone. VIS-NIR spectrometer was utilized to monitor the changes of reflectance. In vitro skin samples were also irradiated by Q-switched Nd:YAG laser (1,064 nm) and then treated by glycerol for 10-60 minutes. Based on the measurement of the reflectance and transmittance of the samples, the optical properties of skin and penetration depth of light were calculated.
Results show that photo-irradiation with appropriate dose combining with the following glycerol treatment is able to reduce in vivo skin reflectance. Compared with the control group, the maximal changes in reflectance are ninefold at 575 nm and eightfold at 615 nm, respectively, which were caused by Q-switched 1,064-nm Nd:YAG laser irradiation and following glycerol treatment. The results for in vitro skin demonstrate that the joint action can significantly increase the optical penetration depth in samples.
The combination of Q-switched Nd:YAG (1,064 nm) laser and glycerol could enhance optical skin clearing efficacy significantly. This study provides a non-invasive way to improve the optical clearing of skin, which will benefit the skin optical therapy.
基于将组织浸入光学透明剂（OCA）的组织光学透明技术可减少散射并增强光在组织中的穿透。然而，表皮的屏障功能限制了OCA的渗透，因此导致通过局部作用对皮肤进行光学透明的效果不佳。在本研究中，应用了多种光照射以增加试剂在皮肤中的渗透性并提高光学透明效果。
研究设计/材料与方法：使用不同剂量的不同光源，即连续波二氧化碳激光、不同脉冲模式的钕：钇铝石榴石激光（532和1064纳米）以及强脉冲光（IPL）（400 - 700和560 - 950纳米）对大鼠皮肤进行体内照射，然后将甘油涂抹在照射区域。利用可见 - 近红外光谱仪监测反射率的变化。体外皮肤样本也用调Q钕：钇铝石榴石激光（1064纳米）照射，然后用甘油处理10 - 60分钟。基于对样本反射率和透射率的测量，计算皮肤的光学性质和光的穿透深度。
结果表明，适当剂量的光照射与随后的甘油处理相结合能够降低体内皮肤反射率。与对照组相比，反射率的最大变化分别在575纳米处为九倍，在615纳米处为八倍，这是由调Q 1064纳米钕：钇铝石榴石激光照射及随后的甘油处理引起的。体外皮肤的结果表明，联合作用可显著增加样本中的光穿透深度。
调Q钕：钇铝石榴石（1064纳米）激光与甘油的组合可显著提高皮肤光学透明效果。本研究提供了一种非侵入性方法来改善皮肤的光学透明，这将有利于皮肤光学治疗。
