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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.
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ObjectiveTo observe the influence of triamcinolone acetonide (TA) on the expression of pigment epithelium-derived factor (PEDF) of human retinal pigment epithelial (RPE) cells. Methods Cultured human RPE cells (4th - 6th generations) were treated with four different concentrations of TA (40, 400, 4× 103 and 4× 104 μg/L) for three different periods (12 or 24 or 48 hours), the levels of PEDF protein in the cell culture supernatant and cell lysates were determined by Western blot. After the initial experiment, RPE cells were treated with or without tumor necrosis factor-α (TNF-α, 20 ng/ml) for 24 hours, followed by TA (400 μg/L) treatment. The levels of PEDF and phospho-p38 mitogen activated protein kinase (p-p38MAPK) protein expression in cell culture supernatant and cell lysates were measured by Western blot. Results TA-treated RPE cells had higher PEDF expression, and 400 μg/L TA group had the highest effect (F= 16.98, P＜0. 05). 400μg/L TA treatment for one, six or 24 hours, with or without TNF-α pretreatment, could all promote the PEDF expression and inhibit the p-p38MAPK protein expression (F= 16.87, 10.28; P＜0. 01). TNF-α pretreatment alone could inhibit PEDF protein expression and promote p-p38MAPK protein expression (F= 16.87, 10. 28; P＜0. 01). Conclusions TA can up-regulate the expression of PEDF, and down-regulate the expression of p-p38MAPK in the cultured human RPE cells.
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Objective To investigate the cytotoxicity of triamcinolone acetonide (TA) on cultured human retinal pigment epithelial (RPE) cells. Methods Effect of TA with different concentraion (0.4, 0.2, 0.1, 0.05, and 0.025 mg/ml) on the proliferation of RPE cells was detected by methyl thiazolyl tetrazolial (MTT) assay; The changes of cellular cycle treated by TA with the drug concentration of IC(50) for 72 hours were measured by flow cytometry (FCM) ananlysis, and the morphological and ultrastructural changes of the cells were observed by phase-contrast microscopy and transmission electron microscopy. Results With the concentration of 0.4-0.025 mg/ml, TA inhibited the growth of RPE cells obviously in a dose-dependent manner compared with the control (P