AIM: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.·METHODS:Seventy-two 3-month aged diabetic rats were randomly divided into 3 groups,each containing 24animals 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 analyze the expression of VEGF mRNA,and light microscopy was used to evaluate the morphology of retinal capillaries.·RESULTS: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,andalso 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.·CONCLUSION: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 bevacizumabchitosan
Yan LuNan ZhouXiao HuangJin-Wei ChengFeng-Qian LiRui-Li WeiJi-Ping Cai
