100 µg plasmid DNA were complexed with in vivo-jetPEI and fibrin sealant, then applied topically over the exterior surface of a 3 x 6 cm flap, on a rat.

OBJECTIVE: To evaluate the role of vascular endothelial growth factor (VEGF) plasmid DNA (pDNA) in improving flap revascularization in a previously developed rat model. Our hypothesis was that the uptake and expression of VEGF pDNA in the wound bed would improve revascularization and flap viability. DESIGN: Twenty-eight male Sprague-Dawley rats received a total dose of 40 Gy electron beam radiation to the ventral abdominal wall. After a recovery period, they underwent a ventral fasciocutaneous flap procedure with a 2-hour ischemia period. Group 1 (n = 14) received topical VEGF pDNA, in vivo cationic polymer, and fibrin sealant. Group 2 (n = 14) received topical cationic polymer and fibrin sealant only. Seven of the rats from each group underwent pedicle ligation at 8 or 14 days. The primary outcome measure was percentage of flap revascularization 5 days after pedicle ligation. RESULTS: Rats receiving VEGF pDNA had a significantly higher rate of flap revascularization (90.8% vs 79.8%) after pedicle ligation at 14 days (P = .045). At 8 days, rats receiving VEGF pDNA (group 1) had an increased rate of flap revascularization (58.2% vs 42.8%) that approached significance (P = .11). CONCLUSION: This study demonstrates the potential of VEGF pDNA to improve revascularization and flap viability in previously irradiated tissue.