TRANSFECTION WITH AFGF CDNA IMPROVES WOUND-HEALING

Somatic gene therapy is a potentially useful strategy for the delivery of growth factors or cytokines to enhance wound healing. Experimental excisional and incisional wounds in impaired-healing diabetic mice (d b/db) were treated with aFGF and with a plasmid coding for aFGF. A euk aryotic expression plasmid composed of the Hst signal peptide sequence in-frame with the human aFGF sequence was used. Transfection of tissu es was accomplished either by direct plasmid uptake or by uptake facil itated with cationic liposomes. The results show that the closure of e xcisional wounds was significantly accelerated (p < 0.05) by topical a pplication of human recombinant aFGF or by transfection with the aFGF plasmid but not by vehicle or control plasmid not containing the aFGF sequence. In incisional wounds, aFGF or transfection with the plasmid significantly increased the wound-breaking strength compared to their corresponding controls (p < 0.05). Quantitative histology of the plasm id-treated incisional wound sections revealed improved wound quality. The transcription of mRNA from human aFGF cDNA in the incisional wound tissue extracts was confirmed by RT-PCR, and the expressed aFGF was d etected by immune dot blot and immunohistochemistry assays. The transf ection was a transient process with a peak at 9 d in db/+ (littermates of the diabetic mice) incisional wounds, at 36 d in db/db incisional wounds, and at 27 d in db/db excisional wounds, Cells transfected with human aFGF occupied up to 6.4% of the transectional area in the wound sites, Thus, aFGF gene delivery resulted in both gene expression and a functional improvement in healing.