A total of 80 partial-thickness
wounds (4.4 cm2 size, 400 micron deep) was inflicted by electrokeratome in the dermal skin layer of four piglets, 15 kg
body weight. The
wounds were treated with gauze (control),
lanolin cream (Lanolor or
Lanolin with emulsifiers, Squibb) or with human
epidermal growth factor (
EGF) delivered in
lanolin cream (10 micrograms
EGF/mL cream). The treatment was applied every 12 hours for 12 to 120 hours after wounding. The reepithelization rate of the
wound was determined by standardized morphometric method. In addition, we measured the thickness of the dermis and cell counts in the dermis. We found that most of the statistically significant enhancement of the epithelization rate, thickness of the dermis, and higher cell count in the dermis were attributed to the effect of
lanolin cream alone. The additional significant enhancement of healing by
EGF over that of
lanolin alone was documented in one of our experiments, but was only marginal. In another experiment using another commercial formulation of
lanolin, we found no difference between the effect of
EGF and
lanolin. Several hypotheses were suggested to explain the effect of the two tested
lanolin cream formulations, which induced strong inflammatory reaction in the
wound.