不同能量下超脉冲点阵CO_(2)激光对兔耳增生性瘢痕胶原代谢的影响及作用机制

Effects of Ultra-Pulse CO2 Fractional Laser at Different Energy Levels on Collagen Metabolism in Rabbit Ear Hypertrophic Scars

目的:探讨不同能量下超脉冲点阵CO_(2)激光对兔耳增生性瘢痕胶原代谢的效果。方法:新西兰健康大白兔5只,于双侧兔耳腹侧设计4个增生性瘢痕模型,共40个模型。采用随机抽样分为四组:低能量激光组(30 mJ)、中能量激光组(50 mJ)、高能量激光组(70 mJ)、瘢痕对照组。每组10个瘢痕模型。予以不同能量激光治疗增生性瘢痕后,观察记录四组增生性瘢痕的大体变化,并于治疗后1周及8周切取瘢痕组织,Masson染色观察胶原沉积情况,测量胶原容积分数;采用免疫组化检测TGF-β1的表达。结果:大体观察,低、中、高能量激光组治疗下瘢痕组织均有不同程度的颜色变浅,质地变软,高度变平,其中以高能量激光组表现最为明显。Masson染色显示,不同能量激光治疗组均可以明显减少瘢痕中的胶原含量,而瘢痕对照组由于瘢痕逐渐成熟,胶原含量会逐渐下降并趋于稳定。免疫组化显示,不同能量激光组对TGF-β1的表达均有抑制作用(P<0.05);其中以高能量激光组作用最明显,差异有统计学意义(P<0.05)。结论:超脉冲点阵CO_(2)激光对瘢痕胶原代谢干预有效,相同点阵密度下,高能量激光干预效果优于低能量激光,推测高能量激光能更好下调TGF-β1的表达,从而改善瘢痕症状。

Objective Investigation of the effects of Ultra-Pulse CO_(2)fractional laser at different energy levels on collagen metabolism in rabbit ear hypertrophic scars.Methods Four New Zealand healthy white rabbits were used in this study,and a total of 40 hypertrophic scar models were created on the ventral side of their bilateral rabbit ears.The models were randomly divided into four groups:low-energy laser group(30 mJ),medium-energy laser group(50 mJ),high-energy laser group(70 mJ),and scar control group.Each group consisted of 10 scar models.After treating the hypertrophic scars with lasers at different energy levels,the macroscopic changes of the scars in the four groups were observed and recorded.Scar tissues were collected at 1 week and 8 weeks post-treatment for Masson staining to observe collagen deposition and measure the collagen volume fraction.Immunohistochemistry was performed to detect the expression of TGF-β1.Results Based on overall observations,scar tissues treated with low,medium,and high-energy laser groups exhibit varying degrees of color lightening,texture softening,and height reduction.Among them,the high-energy laser group shows the most pronounced effects.Masson's staining reveals that laser treatment with different energy levels significantly reduces collagen content within the scars,whereas the collagen content gradually decreases and stabilizes in the scar control group as the scars mature.Immunohistochemical analysis demonstrates that laser groups with different energy levels exhibit inhibitory effects on the expression of TGF-β1,with statistical Significance(P<0.05).Among them,the high-energy laser group exhibits the most significant impact,with statistically significant differences(P<0.05).Conclusion Ultra-pulse CO_(2)fractional laser intervention effectively modulates scar collagen metabolism.Under the same fractional density,high-energy laser intervention yields better results than low-energy laser intervention.It is speculated that high-energy laser can more effectively downregulate the expression of TGF-β1,thereby improving scar symptoms.