Purpose: This study was designed to investigate the effects of the locally supplied endogenous angiogenesis inhibitor vasostatin (VS) on corneal angiogenesis.
Methods: Recombinant VS was expressed and purified. The effects of VS on the proliferation of endothelial cells were investigated using the methyl thiazolyl tetrazolium (MTT) assay in the absence or presence of angiogenic factors such as basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF). Corneal neovascularization was induced by implantation of hydron pellets containing bFGF in rat corneal micropockets. The potency of VS to inhibit corneal angiogenesis was investigated by incorporation of VS with bFGF in hydron pellets or topical application of VS containing eye drops to rat eyes implanted with bFGF pellets. The extent of corneal neovascularization was evaluated by microscopic and histological analyses.
Results: VS potently inhibited the growth of endothelial cells in the absence or presence of angiogenic factors such as bFGF or VEGF. In the rat corneal micropocket assay, concurrent incorporation of VS abolished the bFGF induced neovascularization. When formulated in a methylcellulose eye drop, VS remained intact and functional in a 4 degrees C solution for more than 7 days. Topical application of VS eye drops potently inhibited bFGF induced neovascularization in rat corneas.
Conclusions: The present study effectively demonstrated the potential feasibility of local application of VS for treatment of corneal angiogenesis.