丝素蛋白膜修复兔尿道缺损的实验研究

目的 探索丝素蛋白膜修复尿道缺损的效果.方法 24只雄性新西兰白兔随机分成3组,实验组、对照组Ⅰ及对照组Ⅱ.实验组12只兔切除尿道中段1.5 cm建立尿道缺损模型,应用丝素蛋白膜修复,术后2、4、8、16周每次3只行逆行尿道造影、组织学及免疫组织化学检测;对照组16只兔行尿道海绵体游离后即缝合切口,对照组Ⅱ6只兔切除尿道中段1.5cm建立尿道缺损模型后缝合切口依靠尿道自体再生修复缺损,术后8周、16周对照组Ⅰ及对照组Ⅱ每次3只行逆行尿道造影、组织学及免疫组织化学检测.结果 实验组12只兔应用丝素蛋白膜修复尿道缺损未见尿道狭窄,尿道粘膜细胞及平滑肌细胞修复缺损区,未见纤维化形成,16周时丝素蛋白膜完全降解,粘膜细胞及平滑肌细胞排列有序,免疫组织化学染色证实修复区腔面覆盖细胞为尿道移行细胞.结论 丝素蛋白膜能够诱导尿道粘膜上皮细胞及尿道平滑肌的生长,具有促进尿道缺损修复的能力.

Application of silk fibroin film for repairing rabbit urethral defect

OBJECTIVE: To evaluate the effect of silk fibroin film for repairing urethral defect in rabbits. METHODS: Twenty-four male New Zealand rabbits were randomized into experimental group, control group I and control group II. In the experimental group, a urethral defect of 1.5 cm was induced in the 12 rabbits and repaired with silk fibroin film. The 6 rabbits in control group I without the surgically induced defect served as the sham operation group, and in control group II consisting of 6 rabbits the urethral defect of 1.5 cm was induced without repair. Histological observation and immunohistochemistry were conducted to examine the regenerative segments of the urethra at regular time points between 2 and 16 weeks postoperatively. RESULTS: The 12 rabbits in the experimental group did not show signs of urethral stricture following the surgery. The implanted silk fibroin film for defect repair was degraded completely at 16 weeks and the defect was repaired with smooth urethral mucous membrane lining and orderly arranged smooth muscle cells. Immunohistochemistry identified the cells lining the defect area as the urethral epithelial cells. CONCLUSION: Silk fibroin film can promote the repair of urethral defect by inducing the growth of the urethral epithelial cells and smooth muscle cells.