Lu Yan, Zhou Nan, Huang Xiao, Cheng Jin-Wei, Li Feng-Qian, Wei Rui-Li, Cai Ji-Ping
Department of Ophthalmology, Changzheng Hospital, the Second Affiliated Hospital of the Second Military Medical University, Shanghai 200003, China ; Department of Ophthalmology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing 210002, Jiangsu Province, China.
Department of Ophthalmology, Changzheng Hospital, the Second Affiliated Hospital of the Second Military Medical University, Shanghai 200003, China.
Int J Ophthalmol. 2014 Feb 18;7(1):1-7. doi: 10.3980/j.issn.2222-3959.2014.01.01. eCollection 2014.
To investigate the effects of intravitreal injection of bevacizumab-chitosan nanoparticles on pathological morphology of retina and the expression of vascular endothelial growth factor (VEGF) protein and VEGF mRNA in the retina of diabetic rats.
Seventy-two 3-month aged diabetic rats were randomly divided into 3 groups, each containing 24 animals and 48 eyes. Both eyes of the rats in group A were injected into the vitreous at the pars plana with 3µL of physiological saline, while in groups B and C were injected with 3µL (75µg) of bevacizumab and 3µL of bevacizumab-chitosan nanoparticles (containing 75µg of bevacizumab), respectively. Immunohistochemistry was used to assess retinal angiogenesis, real-time PCR assay was used to analyse the expression of VEGF mRNA, and light microscopy was used to evaluate the morphology of retinal capillaries.
Real-time PCR assay revealed that the VEGF mRNA expression in the retina before injection was similar to 1 week after injection in group A (P>0.05), while the VEGF mRNA expression before injection significantly differed from those 4 and 8 weeks after injection (P<0.05). Retinal expression of VEGF protein and VEGF mRNA was inhibited 1 week and 4 weeks after injection (P<0.05) in group B, and the expression of VEGF protein and VEGF mRNA was obviously inhibited until 8 weeks after injection (P<0.05) in group C. Using multiple comparisons among group A, group B, and group C, the VEGF expression before injection was higher than at 1, 4 and 8 weeks after injection (P<0.05). The amount of VEGF expression was higher 8 weeks after injection than 1 week or 4 weeks after injection, and also higher 1 week after injection compared with 4 weeks after injection (P<0.05). No toxic effect on SD rats was observed with bevacizumab-chitosan nanoparticles injection alone.
The results offer a new approach for inhibiting angiogenesis of diabetic retinopathy and indicate that the intravitreal injection of bevacizumab inhibits VEGF expression in retina, and bevacizumab-chitosan nanoparticles have a longer duration of action.
探讨玻璃体内注射贝伐单抗-壳聚糖纳米粒对糖尿病大鼠视网膜病理形态及视网膜中血管内皮生长因子（VEGF）蛋白和VEGF mRNA表达的影响。
将72只3月龄糖尿病大鼠随机分为3组，每组24只动物、48只眼。A组大鼠双眼在玻璃体平坦部玻璃体内注射3μL生理盐水，而B组和C组分别注射3μL（75μg）贝伐单抗和3μL贝伐单抗-壳聚糖纳米粒（含75μg贝伐单抗）。采用免疫组织化学法评估视网膜血管生成，采用实时PCR法分析VEGF mRNA的表达，采用光学显微镜评估视网膜毛细血管的形态。
实时PCR法显示，A组注射前视网膜中VEGF mRNA表达与注射后1周相似（P>0.05），而注射前VEGF mRNA表达与注射后4周和8周显著不同（P<0.05）。B组注射后1周和4周视网膜VEGF蛋白和VEGF mRNA表达受到抑制（P<0.05），C组直到注射后8周VEGF蛋白和VEGF mRNA表达明显受到抑制（P<0.05）。通过A组、B组和C组之间的多重比较，注射前VEGF表达高于注射后1周、4周和8周（P<0.05）。VEGF表达量在注射后8周高于注射后1周或4周，且注射后1周高于注射后4周（P<0.05）。单独注射贝伐单抗-壳聚糖纳米粒未观察到对SD大鼠的毒性作用。
研究结果为抑制糖尿病性视网膜病变的血管生成提供了一种新方法，并表明玻璃体内注射贝伐单抗可抑制视网膜中VEGF表达，且贝伐单抗-壳聚糖纳米粒具有更长的作用持续时间。
