RESUMO
PURPOSE: To evaluate the antiangiogenic activity of bevacizumab-loaded polyurethane using two animal models of neovascularization. METHODS: The percentage of blood vessels was evaluated in a chicken chorioallantoic membrane model (n=42) and in the rabbit cornea (n=24) with neovascularization induced by alkali injury. In each model, the animals were randomly divided into the groups treated with the bevacizumab-loaded polyurethane device, phosphate-buffered-saline (negative control) and bevacizumab commercial solution (positive control). Clinical examination, as well as histopathological and immunohistochemical evaluation, were performed in the rabbit eyes. Microvascular density in hot spot areas was determined in semi-thin sections of corneal tissue by hematoxylin-eosin staining and factor VIII immunohistochemistry. Immunohistochemical analysis was also performed to evaluate VEGF expression. RESULTS: In the evaluated models, the use of bevacizumab (Avastin®) and the bevacizumab-loaded polyurethane device led to similar results with regard to inhibition of neovascularization. In the chorioallantoic membrane model, the bevacizumab-loaded polyurethane device reduced angiogenesis by 50.27% when compared to the negative control group. In the rabbit model of corneal neovascularization, the mean density of vessels/field was reduced by 46.87% on analysis of factor VIII immunohistochemistry photos in the bevacizumab-loaded polyurethane device group as compared to the negative control (PBS) sections. In both models, no significant difference could be identified between the bevacizumab-loaded polyurethane device and the positive control group, leading to similar results with regard to inhibition of neovascularization. CONCLUSIONS: The present study shows that the bevacizumab-loaded polyurethane device may release bevacizumab and inhibit neovascularization similarly to commercial bevacizumab solution in the short-term.
