ALA-PDT对兔耳增生性瘢痕抑制效应及作用机制的初步研究

Preliminary study in the inhibitory effect and mechanism of ALA-PDT on the hypertrophic scar model in rabbit ears

目的:观察ALA-PDT(5-氨基酮戊酸光动力疗法)对兔耳增生性瘢痕形成的抑制作用及对转化生长因子β1(TGF-β1)表达的影响。方法:在兔耳腹侧面做直径1cm大小全层皮肤缺损创面3个/侧,共60个。随机分为以下三组:高浓度ALA-PDT组(n=20):20%ALA介导PDT治疗;低浓度ALA-PDT组(n=20):10%ALA介导PDT治疗;对照组(n=20):不做治疗,待创面自然愈合。在创面形成术后的第6天、第13天分别进行ALA-PDT治疗,观察治疗组与对照组之间的瘢痕形成率、瘢痕增生指数、胶原纤维含量及TGF-β1表达情况的差异。结果:ALA-PDT治疗降低了瘢痕形成率,其中药物高浓度ALA-PDT组与对照组的差异有统计学意义(P<0.01);药物高浓度ALA-PDT组和药物低浓度ALA-PDT组的瘢痕增生指数、胶原纤维含量与对照组的差异有统计学意义(P<0.05);药物高浓度ALA-PDT组与对照组之间的TGF-β1的表达差异具有统计学显著性(P<0.05)。结论:ALA-PDT对兔耳增生性瘢痕的形成有抑制作用,从而预防创伤后增生性瘢痕形成,该作用可能通过减少TGF-β1的产生而实现。

Objective To investigate the ability of ALA-PDT（5-Aminolaevulinic Acid-based Photodynamic Therapy）in reducing hypertrophic scar formation in a rabbit ear model and further to observe the expression of TGF-β1（transforming growth factor-β1）.Methods The acute dermal wound models on white rabbits＇ ears were established.60 scars were randomly divided into 3 groups： the high concentration ALA experimental group（n=20） received 20%ALA PDT treatment while the low one（n=20） received 10%ALA PDT treatment,and the controlled group（n=20） received no special treatment.The experimental groups received ALA-PDT treatment at two time points postwounding：days 6,13.Specimens were harvested from scars on postoperative 28 days and scar elevation index,fiber collagen contents were measured,TGF-β1 expression was tested by immunochemical staining.Results Compared with the controlled group,scar formation rate in high concentration ALA-PDT treatment group was reduced significantly（P0.05） and the hypertrophic index,fiber collagen contents and the expression of TGF-β1 in both treatment groups were also decreased（with P0.05 in both groups）,there was no significant difference between high and low concentration ALA-PDT treatment groups.Conclusion ALA-PDT may play a role in inhibiting hyperplastic scar formation in rabbit ear,wich probably acted by reducing the expression of TGF-β1.