Microscopic Observation And Mechanism Analysis Of Photo-biological Interaction On Skin Of Rat

The interaction of light and life is a permanent topic during the process of human being development, one of which main application is photo-rejuvenation and laser cosmetology. In recent years, photon-rejuvenation is fashionable in the world, but the theoretical study and the interaction of photo skin were still so poor, and then sufferers and physicians were undergong by complication in clinic and the mechanism was unknown, which are the significance of the subject we have. This thesis was devoted to study the mechanism of the non-ablation photorejuvenation and evaluating the effect after treatments in submicrometer using the means of combining the animal experimental and numerical analysis, so as to disclosure the process of the interacting in photo-skin.The paper was componented of the five parts as follows: In part one, the development course of photo-rejuvenation technology, including the history and actuality, was depicted in brief. The problem in present also was pointed out and the significance of this dissertation was exposed out. The main research contents of the paper were summarized. In part two, the mechanism of the photo-rejuvenation was discussed, the main part of which was the selective photothermolysis, then the reason of the formation of aging skin and that display in pathology was described. This provided the theoretical basis for experiment research. The characteristics and applications of the apparatus using in the experiment was depicted in brief. And then author have discussed the feasibility of the apparatus in this thesis's experiment through the pre-experiment. The experiment research, which major in interaction of intense pulse light source and Er:YAG laser in rat-vivo skin were made. The result of compared group and experiment group was analyzed and summarized. In detail, the rat skin after interaction by IPL, especially the change of the dermas was analyzed. The Morphologic changes of rat skin were observed using laser scanning confocal microscopy after irradiated by IPL in different parameters. And then the tissue sectioning were made, and stained with H.E dyes as the assistant compare. Two-photon microscopy analysises the changesof second harmanic generation and fluorescence spectrum between pre- and after light irradiated.As a supplementary study, the numerical simulation of optical energy and temperature distribution in rat skin were carried out, using the optical and thermal parameters of the skin which obtained by experiential value, and then which results was compared with that of the animal experiments.