Purpose  retinal neovascularization(RNV)is the leading cause of blindness in patients with diabetic retinopathy. This study evaluated the better inhibitory effect of topical incorporation application of vasostatin(VS) with sperminated pullulans(SP) on RNV.

Methods  Recombinant human VS was expressed in Pichia and purified with Ni-NTA agarose. Anti-angiogenic activity of VS plus PS was evaluated in vitro by proliferation, migration and tube formation assays in human umbilical vein endothelial cells (HUVECs). Hyperoxia induced retinal neovascularization lesions were created in C57BL/6J mice .All the model mice were randomly divided into two groups , namely control group and treatment group .Beginning one day after RNV induction, the left eyes of control group mice were treated with PBS buffer, the right eyes of control group mice were treated with eye drops containing 0.2% PS in PBS buffer , the left eyes of treatment group mice were treated with eye drops containing 1 μg/ml VS in PBS buffer and the right eyes of treatment group mice were treated with eye drops containing 1 μg/ml VS plus 0.2%SP in PBS buffer respectively three times daily for 8 days. The extent of RNV was examined by flat mount analysis on day 21 . RNV lesions were further evaluated by histological analysis.

Results  Application of VS plus SP inhibited the proliferation, migration and tube formation of HUVECs . After RNV induction, topical application effect of eye drops containing 1 μg/ml VS plus 0.2% SP in PBS buffer for 9 days was significantly better than that of eye drops only containing 1μg/ml VS in PBS buffer as assayed by flat mounts. Histological analysis also revealed a better attenuated RNV lesions in VS plus SP -treated eyes than VS-treated eyes.

Conclusions  Topical VS plus SP application more effectively suppressed hyperoxia-induced RNV in mice.