Dehydrated form of plasmid expressing basic fibroblast growth factor-polyethylenimine complex is a novel and accurate method for gene transfer to the cornea.

PURPOSE: We describe a novel vector system of nonviral gene transfer into the cornea using a dehydrated form of a plasmid expressing basic fibroblast growth factor-polyethylenimine (p-bFGF-PEI) complex to induce angiogenesis.

METHODS: Corneal neovascularization was evaluated in 48 eyes of Sprague-Dawley rats after implantation of a dehydrated form of PEI containing 1 microg green fluorescent protein (p-GFP-PEI; control group), or 10 microg, 1 microg, or 0.1 microg of p-bFGF-PEI introduced by spin vacuum at ambient temperature. Neovascularization was observed and quantified from day 1 to day 45. Eighteen kDa bFGF protein expression was analyzed by Western blot and immunohistochemistry.

RESULTS: Limbal vessels began to sprout on day 3 in the p-bFGF-PEI groups. The dehydrated form of the p-bFGF-PEI complex induced dose-dependent corneal neovascularization, which reached a maximum on days 24-30 in the 10 microg bFGF group, days 18-24 in the 1 microg bFGF group, and days 15-21 in 0.1 microg bFGF group, and then regressed progressively. No neovascularization was observed in the GFP group.

CONCLUSIONS: The dehydrated form of the p-bFGF-PEI complex is a novel and precise method for controlling the dose, localizing the reagents, and avoiding loss of liquid form during transfection into corneal tissue.