Suppression of choroidal neovascularization by intravitreal injection of liposomal SU5416.

OBJECTIVE

To clarify whether use of angiogenic vessel-homing peptide, Ala-Pro-Arg-Pro-Gly (APRPG)-modified liposomes encapsulating 3-([2,4-dimethylpyrrhol-5-yl] methylidenyl)-indolin-2-one (SU5416), an angiogenesis inhibitor, can inhibit the development of experimental choroidal neovascularization (CNV) in rats.

METHODS

Liposomes were prepared using the thin-film hydration method. To set up the rat experimental CNV model, intense fundus laser photocoagulation at 6 spots per eye was performed on pigmented rats. After photocoagulation, the rats were divided into 4 groups (6 rats in each group): an APRPG-liposomal SU5416 treatment group and control groups treated with a balanced salt solution, APRPG liposomes, or soluble SU5416. Each rat received a single intravitreal injection immediately after the injury. One week or 2 weeks after laser injury, the extent of CNV was evaluated by perfusion with high-molecular-weight fluorescein isothiocyanate-dextran.

RESULTS

Two weeks after injection, the CNV area was significantly (P < .05) smaller in the APRPG-liposomal SU5416-treated group compared with the CNV area in the balanced salt solution-and APRPG liposome-treated groups.

CONCLUSION

Liposomes modified by APRPG and encapsulating SU5416 constitute a potential drug formulation for CNV treatment that would require only a single intravitreal injection.

CLINICAL RELEVANCE: This liposomal delivery may enable the sustained release of small molecules and be a new treatment modality for CNV.