三种剂量630nm弱激光对Wistar大鼠背部皮肤开放型创伤愈合的作用观察

Effects of Low-Level Laser Therapy at 630 Nanometer on Cutaneous Excisional Wound Healings of Wistar Rats with Three Doses Between 1～4 J/cm^2

目的:从创伤面积收缩率和组织病理学角度观察630nm连续输出型弱激光,在功率密度一定(10mW/cm^2)时,每日创面照射剂量分别为1.2J/cm^2、2.4J/cm^2和3.6J/cm^2对Wistar大鼠背部皮肤开放型创伤愈合的影响。方法:用手术剪在每只Wistar大鼠背部造四个圆形、全层皮肤切除的创口,按照完全随机设计,将同一只大鼠背部的四个创口划分到空白对照组和三个不同剂量照射组,造创半小时后照射,连续照7天;再将大鼠随机分为1～6组,依次在造创后的第12、24、48、72、120和168小时处死取材,进行HE染色,光镜下评价;对第5、6组的样本增加马松(Masson)特染,光镜下评价;并对第6组在每次照射前用无菌薄膜沿边缘描记一次创面,采用ImageJ图像处理软件计算创口面积,对数据进行方差分析。结果:创伤面积的方差分析结果表明,空白对照组与各照射组之间不存在统计学差异;而组织病理学观察结果表明,弱激光照射组较空白对照组有以下特点:炎性期持续时间短,肉芽组织出现早,在同一时期,肉芽组织成熟、胶原数量多且其中成熟胶原所占比重大、表皮新生速度快,并且,这种优势随着所用剂量的增加而更加明显。结论:功率密度为10mW/cm^2,剂量分别为1.2J/cm^2、2.4J/cm^2和3.6J/cm^2的630nm弱激光照射能够产生创伤部位局部效应,促进Wistar大鼠背部皮肤开放型创伤的愈合过程,并且随着剂量的增加,创伤愈合效果越好。

Objective：To study on the effects of three different daily doses between 1-4J/cm^2 of the irradiation of Low l.evel Laser Therapy （LLLT） at 630 nanometer （nm） on dorsal cutaneous excisional wound healings of Wistar rats under a constant power density of 10mW/cm^2. Methods： We made four identical circular full-skin excisions symmetrically on the dorsum of each rat, and then randomly classified them into the control group, the 1.2J/cm^2 dose group, the 2.4J/cm^2 dose group and the 3. 6J/cm^2 dose group. Wounds were irradiated respectively every 24 hours（h） for 7 consecutive days and the first executations were carried out half-hour right after the excisions had been done. We divided all the 48 rats at random into 6 time point groups （group 1 6） and sampled each group separately at 12h, 24h, 48h, 72h, 120h, and 168halter the first irradiations. Samples of all the 6 groups were evaluated under HE staining, while Masson staining were only done to group 5 and 6. We also recorded margins of each wound of the 8 rats in the 6th group using sterial films before every irradiation except for the first ones, by making use of ImageJ, an imaging processing software, we then calculated the areas and did ANOVA analysis to the acquired data. Results： The ANOVA analysis of areas of the wounds indicates that there were no statistical differences among the control group and the other 3 different doses groups. However, microscopic observations, both HE staining and Masson staining, could tell evidently better results of LLLT groups when compared to the control group, including the shorter period of inflam- mation, the greater development of granulations and collagens, and better epithelialization. The microscopic evaluations also suggest that larger dose brings better wound healing results within the 1-4J/cm^2 range. Conclusions： The three doses groups （1.2J/cm^2 , 2.4J/cm^2 , 3.6J/cm^2） of LLLT at 630nm showed effective results, though not statistically evident, on dorsal eutaneous excisional wound healings of Wistar rats under the power density of 10 mW/cm^2 , and larger doses lead to better outcomes.