考布他汀A4隐形/靶向脂质体抑制脉络膜新生血管的研究

目的观察考布他汀A4（CA4）隐形/靶向脂质体对激光诱导的棕色挪威（BN）大鼠脉络膜新生血管（CNV）的抑制作用。方法成年BN大鼠20只,647 nm氪红激光光凝视网膜至Bruch膜破裂诱导CNV,脂质体药物的制备采用薄膜分散-超声法。动物模型随机分为考布他汀A4磷酸盐（CA4P）组、连接精氨酸-甘氨酸-天冬氨酸三肽（RGD）靶头的CA4靶向脂质体（RGD-SSL-CA4）组、连接RGD靶头的空白靶向脂质体（RGD-SSL）组、不连接RGD靶头的CA4隐形脂质体（SSL-CA4）组和生理盐水（NS）组,于激光光凝后3 d和10 d经大鼠尾静脉给药。光凝后1周和2周进行荧光素眼底血管造影（FFA）检查,观察激光斑处荧光素渗漏情况。激光光凝后2周行FITC-Dextran灌注后处死大鼠制作脉络膜铺片,计算CNV面积。结果 RGD-SSL-CA4组视网膜光凝斑处的荧光素渗漏明显较其他组轻。RGD-SSL-CA4组CNV面积为（25 360±14 050）μm2,NS组为（46 500±17 230）μm2,RGD-SSL-CA4组较NS组明显缩小,差异有统计学意义（P〈0.05）;CA4P组为（38 290±19 290）μm2,RGD-SSL组为（44 150±16 410）μm2,SSL-CA4组为（39 690±17 850）μm2,与NS组比较差异均无统计学意义（P〉0.05）。结论 RGD-SSL-CA4具有长循环、靶向的双重优势,可显著抑制激光诱导的CNV。

Effects of combretastatin A4-loaded stealth/targeted liposomes on regression of choroidal neovascularization

Background Combretastatin A4（CA4）,one of the compounds currently undergoing clinical evaluation has been reported to be capable of destroying neovascularization.Choroidal neovascularization（CNV） is a primary menifastation of many causing-blindness eye diseases.ObjectiveThis experiment was to evaluate the inhibiting efficacy of CA4-loaded stealth/targeted liposomes on laser-induced CNV in rats.MethodsCNV animal models were induced in 20 adult Brown-Norway（BN） rats by photocoagulating the retina with Krypton-red laser to create the rupture of Bruch＇s membrane.The drug liposome was prepared with film dispersion-ultrasonic method.Animal models were randomly divided into five groups according to the different drugs injection.Combretastatin A4 phosphate（CA4P,containing 7mg/kg CA4）,CA4-loaded arginine-glycine-aspartic acid tripeptide（RGD） modified poly（ethyleneglycol）-coated sterically stabilized liposomes（RGD-SSL-CA4,containing 7mg/kg CA4）,blank RGD-SSL,CA4-loaded poly（ethyleneglycol）-coated sterically stabilized liposomes（SSL-CA4,containing 7mg/kg CA4） and normal saline solution（NS） were respectively administered in the third day and tenth day after photocoagulation of retina via caudal vein.CNV area was examined by fluorescein fundus angiography（FFA） 1 and 2 weeks after laser photocoagulation.At the end of 2 weeks,fluorescein-labeled dextran（FITC-Dextran,molecular weight=2×106） were perfused via left ventricle and choroidal flatmounts were prepared for observation and calculation of CNV area under the confocal microscope.Use of experimental animals followed the Standard of Association for Research in Vision and Ophthalmology.ResultsThe fluorescein leakage area was obviously reduced in RGD-SSL-CA4 group.The mean CNV area was（25360±14050）μm2 in RGD-SSL-CA4 group,and that of NS group was（46500±17230）μm2,showing a statistically significant difference between them（P0.05）.No significant differences were found in CNV area between SSL-CA4 group and NS group（38290±19290μm2 vs 46500±17230μm2）;RGD-SSL group and NS group（44150±16410μm2 vs 46500±17230μm2）;SSL-CA4 group and NS group（39690±17850μm2 vs 46500±17230μm2）（P0.05）.ConclusionRGD-SSL-CA4 has the long cycle time and targeted action in inhibiting laser-induced CNV.