Adenoviral-mediated overexpression of platelet-derived growth factor-b corrects ischemic impaired wound healing

Chronic wounds represent a major clinical problem with significant morbidity and healthcare expenditures, but no effective therapies. Topical platelet-derived growth factor-BB trials have required large and repeated doses to achieve only a modest effect. We examined the ability of an adenovirus containing the platelet-derived growth factor-B transgene to improve the rate of wound healing through induction of platelet-derived growth factor-B overexpression in cells participating in the wound healing response. We treated excisional wounds in the ischemic rabbit ear, which have a 60% delay in healing, with vehicle, 10⁶, or 10⁸ plaque-forming units of an adenovirus containing the platelet-derived growth factor-B per wound (n = 19). At 7 d this resulted in a decrease in the epithelial gap from 3.4 ± 1 mm (mean ± SD) in vehicle-treated wounds to 1.9 ± 1.8 mm (mean ± SD, p < 0.05) when treated with 10⁶ plaque-forming units of an adenovirus containing the platelet-derived growth factor-B, and 0.7 ± 1.1 mm (mean ± SD, p < 0.001) when treated with 10⁸ plaque-forming units of an adenovirus containing the platelet-derived growth factor-B. Ischemic excisional wounds treated with 10⁸ plaque-forming units of an adenovirus containing the platelet-derived growth factor-B even healed more rapidly than non-ischemic excisional wounds treated with vehicle (p < 0.05). In contrast, 5 μg of platelet-derived growth factor-BB protein (n = 2) resulted in only modest granulation tissue at the margin, but no significant differences in epithelial gap (3 ± 0.6 mm, mean ± SD). Plaque-forming units (10⁶ or 10⁸) of an adenovirus containing the β-galactosidase transgene (n = 4) impaired wound re-epithelialization with an epithelial gap of 5.11 ± 0.69 mm, mean ± SD, p < 0.004, and 3.8 ± 0.57 mm, mean ± SD, p < 0.07, respectively. Adenoviral-mediated gene transfer of platelet-derived growth factor-B overcame the ischemic defect in wound healing and offers promise in the treatment of chronic nonhealing wounds. The vulnerary effects of platelet- derived growth factor-B overexpression were sufficient to overcome the adverse effects of the adenovirus or transgene on wound healing.