Effect On Structure And Function Of Rat Skin By Using Optical Clearing Agent

NIR technology has been widely applied in disease diagnosis, but the penetration of light is restrained by highly scattering in the skin. Optical tissue clearing by hyper- osmotic chemical agents can reduce the scattering of skin and significantly increase light penetration depth, which benefits from obtaining deeper structural information of skin. However,the present study of optical tissue clearing only provide limited information which is qualitative or half-quantitatively and the less attention is paid to the effect on the function of subcutaneous vessels in the optical clearing process.In this dissertation, we evaluate the potential role of optical clearing by glycerol from two aspects.Firstly, we investigate the effects of glycerol on structure and record the reduced scattering coefficient of skin by double integrating spheres system. In the experiment, the change of reduce scattering coefficient of skin is in direct proportion to the concentration of glycerol, which matches the theory exactly.Secondly, we investigate the morphological and functional effects of glycerol on blood vessels with laser speckle contrast imaging technology and model of hamster dorsal skin flap window. The results show that application of glycerol to the subdermis can result in flow decrease and vessels stasis for high concentration.The improved white light imaging is detected from the subdermis when glycerol applied to the epidermal side. The effect of glycerol on vessels is also existed by the indirect application of glycerol. However, it is notable that the velocity is increased in this situation. The indirect effect is also proportion to the concentration of glycerol. The high concentration is, the more slowdown is.The study on the effect of optical clearing agents to the morphological and functional of skin provides a new break for selecting secure OCA.