曲安奈德/聚乳酸己内酯载药静电纺丝膜的抗兔眼滤过泡瘢痕化作用

背景 青光眼滤过术后滤过道的瘢痕形成是手术失败的主要原因,近年来多采用小梁切除术中局部使用抗瘢痕形成药物的方法来保持滤过道的开放,但药物可引起并发症.研究证实,聚乳酸己内酯(PLCA)材料制作的静电纺丝膜可作为负药载体以达到药物缓释的目的,但其在青光眼滤过术中的作用尚未证实. 目的 探讨小梁切除术联合巩膜层间填充负载曲安奈德(TA)静电纺丝膜在兔眼穿透性小梁切除术中抗瘢痕化的作用及可行性.方法 利用静电纺丝技术制备TA/PLCA载药静电纺丝膜,扫描电子显微镜下检测其表面超微结构,采用高效液相色谱仪检测体外药物缓释性能.采用前房注射卡波姆法制备单眼青光眼动物模型,将造模成功的40只新西兰白兔均行穿透性小梁切除术并采用随机数字表法分为5个组,每组8只眼.TA/PLCA载药静电纺丝膜组、PLCA静电纺丝膜组和羊膜组在术中于巩膜瓣下分别植入TA/PLCA载药静电纺丝膜、PLCA静电纺丝膜或羊膜.TA组术眼术毕在结膜下注射40 mg/ml TA溶液而术中不植入任何植片,单纯小梁切除术组仅行小梁切除术.分别于术后1、2、4、8和12周测量术眼眼压,并采用裂隙灯显微镜观察滤过泡的形态变化;于术后12周制备术眼滤过泡组织切片,采用苏木精-伊红染色法检查各组术眼滤过泡的组织病理学变化.结果 制备的PLCA静电纺丝纤维直径为0.5 ～1.5 μm,呈空间立体网状结构,而TA/PLCA静电纺丝膜结构与PLCA静电纺丝膜相近,可体外缓释药物14d.单纯小梁切除组术眼滤过泡于术后8周前全部消失,术后12周TA/PLCA载药静电纺丝膜组8只眼均存在功能性滤过泡,PLCA静电纺丝膜组中维持功能性滤过泡者5只眼,羊膜组和TA组中分别为4只眼.术后12周各组术眼的眼压明显不同,TA/PLCA载药静电纺丝膜组术眼眼压最低,而单纯小梁切除术组术眼眼压最高,各组间比较差异均有统计学意义(均P=0.000).组织病理学检查显示,术后12周TA/PLCA载药静电纺丝膜组术眼滤过道存在,滤过腔表面上皮化;PLCA静电纺丝膜组、羊膜组、TA组术眼滤过腔存在微小空隙,可见周围组织增生,而单纯小梁切除术组滤过腔消失,组织增生呈瘢痕化. 结论 TA/PLCA载药静电纺丝膜具有纳米级微观结构,体外药物缓释性能较好.小梁切除术中联合巩膜瓣下TA/PLCA载药静电纺丝膜植入可明显抑制手术区滤过腔瘢痕化,可能是TA抑制瘢痕作用与静电纺丝膜支架作用共同作用的结果.

Anti-scarring effects of triamcinolone acetonide/polylactic acid caprolactone drug-loaded electrospinning film with trabeculectomy in rabbits

Background Scarring of filter bleb is a main cause of failure after trabeculectomy.Administration of anti-proliferation dugs during filtering surgery can maintain the opening of filtering pathway,but some serious complications occure after the drug use.Researches showed that polylactic acid caprolactone (PLCA) drug-loaded electrospinning film can release drug slowly,but its application in glaucoma is seldom.Objective The aim of this study was to evaluate the anti-scarring effects of non-penetrating trabeculectomy combined with sclera interlayer implantation of triamcinolone acetonide (TA)/PLCA drug-loaded electrospinning film in rabbit.Methods TA/PLCA drug-loaded electospinning film was prepared by electrospinning and its surface ultrastructure was observed under the scanning electron microscope.The drug release properties were detected by high performance liquid chromatograph.Ocular hypertensive models were established in New Zealand white rabbits by injecting carbomer into the anterior chamber of the right eyes,and the 40 models were randomized into 5 groups,8 eyes for each group.TA/PLCA drugloaded electrospun membrane,PLCA electrospun membrane or amniotic membrane was implanted beneath the scleral flap during trabeculectomy respectively in the TA/PLCA group,PLCA group or amniotic group,and 40 mg/ml TA was subconjunctivally injected in the TA group.Only trabeculectomy was performed in the simple trabeculectomy group.Intraocular pressure (IOP) was measured,and the shape of filtering bleb was examined under the slit lamp 1 week,2,4,8 and 12 weeks after surgery.The section of filtering bleb was prepared 12 weeks after surgery for the histopathological examination.The use and management of experimental animals was in line with animal ethics.Results The similar three-dimensional reticular structure was seen between TA/PLCA and electrospun membrane with the fiber diameter 0.5-1.5 μm.TA was released stably for 14 days.All the filtering blebs were disappeared in the simple trabeculectomy group during 8-week duration after operation.At 12 weeks after operation,the functional bleb was found in all the 8 eyes of the TA/PLCA group,5 eyes of PLCA group,4 eyes of the amniotic group and 4 eyes of the TA group.The IOP was significantly different among the groups,with the lowest IOP in the TA/PLCA group and the highest IOP in the simple trabeculectomy group (all at P =0.000).Histopathological examination showed that the filtering pathway remained opening in all 8 eyes with the epithelization of bleb surface in the TA/PLCA group,and interspaces of the filtering pathway was explayed in the PLCA group,amniotic group and TA group,while fibrosis of filtering pathway was seen in the simple trabeculectomy group at 12 weeks after surgery.Conclusions TA/PLCA drugloading electrospun membranes presents with nanoscale microstructure and good drug-release properties in vitro.Implantaion of TA/PLCA beneath the scleral flap during trabeculectomy can inhibit the fibrosis of filtering pathway.