EphA2 Targeted Doxorubicin Stealth Liposomes as a Therapy System for Choroidal Neovascularization in Rats

PURPOSE. To enhance drug uptake in RPE cells, improve efficacy for choroidal neovascularization (CNV), and reduce drug toxicity, an EphA2-targeted nanocarrier loaded with doxorubicin (DOX) was developed by conjugation with a homing peptide YSA. METHODS. The YSA was coupled to PEGylated lipid. Then, YSA-modified DOX stealth liposomes (YSA-SSL-DOX) were prepared and characterized. Their uptake in a human RPE cell line (ARPE-19) was evaluated. After intravitreous injection, their efficacy against CNV was assessed in a laser-induced rat model. Finally, TUNEL test and morphology observation on rat retina were conducted. RESULTS. The prepared YSA-SSL-DOX was approximately 110 nm in particle size, with an encapsulation efficiency of DOX more than 95%. The leakage of DOX from YSA-SSL-DOX was very slow. The expression of EphA2 on the CNV was confirmed. Both flow cytometry and confocal microscopy studies revealed that YSA-SSL-DOX could facilitate the uptake of liposomal DOX into ARPE-19 cells. Treatment with YSA-SSL-DOX (2.5 mu g DOX) resulted in a significant reduction in the CNV area of rats compared with the unmodified liposomal DOX and normal saline (P < 0.05). No obvious toxicity of YSA-SSL-DOX on rat retina was found. CONCLUSIONS. EphA2-targeted stealth liposomes might be an effective delivery and therapy system for angiogenesis-related diseases in the retina. (Invest Ophthalmol Vis Sci. 2012; 53: 7348-7357) DOI:10.1167/iovs.12-9955