机械张力致小鼠增生性瘢痕形成的模型构建

The construction of mouse hypertrophic scar model initiated by mechanical load

目的探索机械张力在增生性瘢痕形成中的作用,构建机械张力致小鼠增生性瘢痕形成的动物模型。方法将健康C57BL/6小鼠随机分为对照组和实验组,于两组小鼠背部正中做2 cm长线性切口,术后第4天拆除缝合线,并安装机械牵拉装置,对照组不牵拉,实验组间断牵拉14 d。分别于牵拉14 d后(牵拉结束当天)、牵拉结束后30 d和60 d拍照并取材,HE染色分析两组瘢痕组织的病理学变化,Masson染色计数瘢痕组织的细胞数量,分析其胶原分布情况,并进行统计学分析。结果牵拉14 d后,实验组形成了类似于人体瘢痕组织的红色无毛区域,平均面积(3.92±1.24)mm^2,20倍物镜下每视野细胞数为(292±34)个,胶原面积为(0.115±0.015)mm^2;对照组瘢痕区域成线状,其瘢痕面积、细胞数目和胶原含量均小于实验组,组间差异均具有统计学意义(P<0.05)。牵拉结束后30 d和60 d结果与牵拉14 d时相近。结论机械张力加载诱导形成的小鼠增生性瘢痕至少可以维持60 d,构建的增生性瘢痕实验模型有利于推动小鼠创伤后瘢痕形成机制探索。

Objective To explore the role of mechanical load on the formation of hypertrophic scars and to establish an animal model of hypertrophic scars initiated by mechanical load. Methods Healthy C57BL/6 mice were randomly divided into a control and an experimental group. A linear incision of 2 cm was made in the middle of the back of the mice in both groups, and the stitches were taken out at 4 days postoperative. A mechanical tractive device was installed on the skin, and the wounds were pulled every other day during the next 14 days in the experimental group. No mechanical tractive device was applied in the control group. Photos were taken of the hypertrophic scar tissues and they were harvested at 30 and 60 days after the mechanical traction was finished. Histopathological changes of the hypertrophic scar in both groups were analyzed by HE staining. The number of cells in the hypertrophic scar were counted by Masson staining, and the distribution of collagen was also analyzed. Statistical analysis was performed. Results An apparent red hairless area similar to human scar tissue was observed in the experimental group. The average area was(3.92±1.24) mm2. The number of cells of each visual field under 20 times objective lens was 292±34, and the area of collagen was(0.115 + 0.015) mm2. In the control group, the scar was linear and the area of scar tissue, the number of cells, and the area of collagen were less than those of the experimental group. The difference was statistically significant(P< 0.05). The results at 30 and 60 days postoperative were similar to those at 14 days. Conclusion Hypertrophic scars in mice initiated by mechanical load can be maintained for at least 60 days. This established experimental model of hypertrophic scar was facilitated to explore the mechanism of scar formation after trauma in mice.