Objective: To evaluate the effect of liposomes mediated plasmid encoding endostatin (ES) for inhibiting experimental corneal neovascularization (CNV).
Methods: Thirty New Zealand albino rabbits were sutured on the superior cornea. Animals were randomly divided into 3 groups. Different reagents were injected at each group:liposomes and plasmid encoding human ES complex in the group 1, liposomes and carrier plasmid complex in the group 2 and saline in the group 3. The occurrence and development of CNV were observed by slit-lamp microscope 3, 7, 14, 21 and 28 days after suturing, the size of CNV area was measured and calculated. Immunohistochemistry was used to detect the ES protein expression in cornea and limbus at different time points.
Results: The appearance time of CNV was (6.85 +/- 0.69) d in group 1, (3.43 +/- 0.53) d in group 2 and (3.14 +/- 0.69) d in group 3. Significant difference in appearance time of CNV was found between the group 1 and the others (F = 100.24, P < 0.05). No significant difference was found between the group 2 and group 3. The size of CNV areas of group 1 were significantly smaller than that of the groups 2 and 3 at every time point (F = 72.662, 75.601, 27.729; P < 0.05). ES protein expression in group 1 was detected at superior limbus and the cornea, with the highest level of expression at 3 days, gradually decreased after 7 days and had a very small quantity of expression at 28 days. ES protein expression was not detected in the groups 2 and 3.
Conclusion: Liposomes mediated plasmids encoding ES can be transferred to cornea and limbus tissues by subconjunctival injection, with the highest levels of expression at 3 days posttransfer and can suppress corneal neovascularization at certain degrees.