干扰素/聚乳酸-羟基乙酸共聚物及壳聚糖/聚乳酸-羟基乙酸共聚物复合膜对椎板切除后脊髓c-fos表达的影响

Effect of interferon/poly(lactic-co-glycolic acid) and chitosan/poly(lactic-co-glycolic acid) composite membrane on expression of c-fos in spinal cord after laminectomy

背景:应用硬膜外阻隔材料是预防椎板切除术后硬膜外瘢痕粘连的一种方法,而制备既有机械阻隔能力,又有抑制成纤维细胞能力的复合膜是其研究方向。目的:制备壳聚糖/聚乳酸-羟基乙酸共聚物(poly(lactic-co-glycolic acid),PLGA)与干扰素/PLGA复合膜,观察其减少脊髓伤害性刺激因子c-fos表达的作用。设计、时间及地点:2005-05/2007-04在中科院长春应用化学研究所完成材料制备,随机对照动物实验在解放军第二○八医院实验动物室完成。材料:PLGA膜、壳聚糖/PLGA及干扰素/PLGA复合膜由中科院长春应用化学研究所制备。方法:大耳白兔120只行L2及L4椎板切除,然后随机分为6组,每组20只,于椎板缺损区处理如下:①空白对照组:硬膜外不放任何物质。②自体游离脂肪组:取皮下脂肪贴于硬膜表面。③透明质酸钠组:透明质酸钠1mL涂于硬膜外。④PLGA膜组、壳聚糖/PLGA及干扰素/PLGA复合膜组:分别将各种膜修剪成合适大小植于硬膜外。主要观察指标:术后2,4,6,8周处死动物,取L1～2节段脊髓,对L2脊髓横切片并行免疫组化染色,显微镜下观察并计数Fos样免疫反应阳性细胞。结果:脊髓内有c-fos的表达,随时间的增长,其表达量逐渐增多,主要在脊髓背角浅层;实验各组Fos样免疫反应阳性细胞计数均低于空白对照组(P<0.01),晚期以壳聚糖/PLGA复合膜及IFN/PLGA复合膜组的表达量少,与其他组比较差异有显著性意义(P<0.01)。结论:壳聚糖/PLGA与干扰素/PLGA复合膜可减少椎板切除术后脊髓c-fos的表达。

BACKGROUND： Epidural resistance materials are an approach to prevent the epidural scar adhesion after laminectomy. A composite membrane of mechanical separation and fibroblast inhibition is promising to be studied widely. OBJECTIVE： To prepare the interferon （IFN）/poly（lactic-co-glycolic acid） （PLGA） and chitosan/PLGA composite membranes, and to observe the effect on decreasing the expression of c-fos in spinal cord after laminectomy. DESIGN, TIME AND SETTING： The materials were prepared in Changchun Institute of Applied Chemisty, Chinese Academy of Sciences; The randomized control animal tests were performed in Animal Experimental Room of the 208 Hospital of Chinese PLA from May 2005 to April 2007. MATERIALS： PLGA membrane, chitosan/PLGA composite membrane and IFN/PLGA composite membrane were prepared in Changchun Institute of Applied Chemisty, Chinese Academy of Sciences. METHODS： L2 and L4 laminectomies were performed in 120 rabbits, which were then randomly divided into six groups （n=20）： Blank control group received nothing on epidurals; Autogenous free fat group： The exposed duras were covered with subcutaneous fat; Sodium hyaluronate group： 1 mL sodium hyaluronate was dripped on dura maters; PLGA membrane, chitosan/PLGA composite membrane and IFN/PLGA composite membrane groups： The exposed dura were covered with one of the three membranes at a suitable size. MAIN OUTCOME MEASURES： The animals were killed at 2, 4, 6 and 8 weeks postoperatively. L1-2 spinal cords were obtained, the transverse slices of spinal cords were made, which were examined by immunohistochemical staining with Fos. The Fos-like immunoreactive cells were counted. RESULTS： There was expression of c-fos in spinal cord, which was mainly in superficial layer of spinal cord dorsal horn and the expression increased with time going on. The count of Fos-like immunoreactive cells in the experimental groups was significantly lower than control group （P 〈 0.01）. At later period, there was significant difference between chitosao/PLGA group, IFN/PLGA group and other groups （P 〈 0.01）. CONCLUSION： Chitosan/PLGA composite membrane and IFN/PLGA composite membrane can decrease the expression of c-fos in spinal cord after laminectomy.