Experimental model for local application of growth factors in skin re-epithelialisation

We did an experimental study to assess the effects of different growth factors on re-epithelialisation of skin wounds by creating a partial-thickness defect in rats with a handle dermatome. Three different growth factors that are particularly involved in the re-epithelialisation phase of wound repair (epidermal growth factor (EGF), keratinocyte growth factor (KGF), and basic fibroblast growth factor (FGF-b) n = 10 in each group) were applied locally in a hydrocolloid dressing containing solutions of the different factors (EGF 10 micrograms/ml, KGF 3.3 ng/ml, bFGF 1 microgram/ml). The dressings were changed daily. The thickness of the epithelium, the percentage of re-epithelialisation, and the maturity of the epithelium were quantified and measured morphometrically. The results showed that: the experimental model allowed us to apply the growth factors, while continuously maintaining the dose within the maximum activity of the growth factor; when EGF, KGF, and bFGF were given according to the protocol there was significant thickening of the new epidermis (p < 0.01) and acceleration of the re-epithelialisation (p < 0.05) rate compared with controls, and significantly more mature epithelium grew (p < 0.05) all of which were evident on both the third and the fifth days; and EGF and KGF cause a more epidermal thickening than bFGF.