Combination of Targeted PDT and Anti-VEGF Therapy for Rat CNV by RGD-Modified Liposomal Photocyanine and Sorafenib

PURPOSE. To achieve a combination therapy of targeted PDT and anti-VEGF for choroidal neovascularization (CNV). METHODS. Arg-Gly-Asp (RGD)-modified liposomes encapsulating photocyanine and sorafenib (RGD-SSL-[P]-[S]) were prepared and characterized. Drug concentration in RGD-SSL-[P]-[S] and irradiation time were optimized on ARPE-19 and HUVEC cells in vitro. A laser-induced CNV rat model was used to assess the efficacy of this targeted combinational system. The effect of RGD-SSL-[P]-[S] on the retinal structure of BN rats was also examined. RESULTS. The particle size of RGD-SSL-[P]-[S] was approximately 100 nm, with a encapsulation efficiency more than 90% for both photocyanine and sorafenib. From RGD-SSL-[P]-[S], the release rate of photocyanine was approximately 22%, whereas that of sorafeinb was approximately 40% at 48 hours. With the optimal drug concentration and irradiation time, RGD-SSL-[P]-[S] exhibited cytotoxicity only to HUVEC without obvious damage to normal ARPE-19 cells. Rats treated with RGD-SSL-[P]-[S] showed the least CNV area and fluorescein leakage in fluorescein fundus angiography. RGD-SSL-[P]-[S] was also found safe to the rat retina. CONCLUSIONS. Combination of targeted PDT and anti-VEGF might be an effective therapy for CNV.