Treatment of Choroidal Neovascularization Using Nanoparticle Coupled to Integrin vβ3-Targeted Gene Delivery System

Abstract

Purpose: : We previously showed that α_vβ₃ integrin-ligand coupled cationic nanoparticle (NP) is able to bind to and deliver a green fluorescing protein plasmid to the abnormal endothelial cells of the laser induced choroidal neovascularization(CNV) in rats. Therefore, we would like to investigate the therapeutic efficacy of α_vβ₃ integrin-ligand coupled cationic NP containing a dominant negative Raf mutant gene (ATPµ-Raf) in laser-induced CNV.

Methods: : CNV lesions were induced in Brown Norway rats using laser photocoagulation. In the treatment group, rats received intravenous NP(1mg/kg) containing ATPµ-Raf(1µg/kg, total volume 350 µl)on days 1, 3, and 5 after laser photocoagulation. In the control group, rats received no treatment, injection with nontargeted NP containing ATPµ-Raf, injection with ATPµ-Raf only, and injection with α_vβ₃ integrin-ligand coupled cationic NP only. CNV were examined by fundus fluorescein angiography on days 7 and 14 and by FITC-dextran flat mounts on day 14. TUNEL positive cells were quantified in the outer nuclear layer and CNV in cyrosections on day 7 and 14.

Results: : Flatmount analysis showed that NP with ATPµ-Raf significantly decreased the surface area of laser-induced CNV by 27.3 % compared with vehicle treated control animals (P<0.001). Moreover, NP with ATPµ-Raf treated animals had significantly fewer TUNEL-positive cells in the photoreceptor layer than did the control animals (P < 0.05).

Conclusions: : Systemic administration of α_vβ₃-targeted delivery of ATPµ-Raf via nanoparticles leads to reduced size and leakage of laser induced CNV.

Keywords: choroid: neovascularization • laser • apoptosis/cell death