PURPOSE: Polypeptide growth factors have stimulated an enormous surge in wound healing research over the last few decades. Models of impaired wound healing that mimic clinical settings have been developed to further investigate how these growth factors might reverse the impairment. The present work displays a growth factor delivery system, containing TGF-B and FGF that can successfully reverse the impaired wound healing seen in a radiated rat wound. METHODS AND MATERIALS: Ninety-six Sprague-Dawley rats underwent dorsal skin surface irradiation of 2,500 rads via a medical linear accelerator capable of producing energy of 6 MeV. Six groups of sixteen rats were made with some receiving no growth factor, one growth factor, or both. Two days after radiation, incisions were made on the dorsal skin and the specific growth factor system was then placed. On post-wounding days 4, 7, 14, and 28, euthanization of four rats in each group was performed. Wounds were then harvested for histological and tensometric analysis. RESULTS: This radiated rat model proved to be a successful impaired model of healing when compared to normal healing in the rat model (p<0.001). On post-wounding day 14, wounds that contained TGF-B and FGF together and individually demonstrated a statistically significant increase in wound breaking strength when compared to radiated controls (p<0.05). Statistical analysis was performed using two-way analysis of variance all pairwise multiple comparison procedures (Student-Newman-Keuls Method). Growth factor treated wounds also revealed a general increase in cellularity and more stable collagen architecture throughout the study. Hematoxylin-eosin, mallory trichrome, and sirius red stains were used for the histological analysis. CONCLUSIONS: Significant reversal of wound healing impairment was demonstrated by the radiated rat wounds treated with FGF and/or TGF-B on day 14. We attribute much of this to the increase in cellularity and the mature collagen framework seen in the growth factor treated wounds most prominent at this time-point.
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