Healing kinetics of oral soft tissue wounds treated with recombinant epidermal growth factor: Translation from a canine model

Abstract

Objective: To test whether or not topically administered recombinant human epidermal growth factor (rhEGF) accelerates the early healing phase of oral soft tissue wounds. Methods: One day following the creation of palatal defects (n = 6/animal), 14 dogs were allocated to one of the following five groups: spontaneous healing (SH), vehicle ointment (V), vehicle ointment + rhEGF at concentrations of 1 μg/g (EGF1), 10 μg/g (EGF10) or 50 μg/g (EGF50). Topical administration of ointments was repeated twice per day until sacrifice at days 8 and 16. Wound area was clinically monitored. Keratinocytes proliferation (Ki67-immunolabelling), inflammatory response (IR) and areas of collagen (C) and granulation tissue (GT) were histologically measured. Kruskal–Wallis test with Dunnett correction was used for multiple group statistical comparisons. Results: Clinically, in comparison with SH, a significantly smaller wound area was observed in groups EGF1 and EGF10 at day 8 (p < 0.05). At day 16, wound closure reached 97.8% in group EGF1 compared to 83.2% in group SH, albeit no statistically different. Histologically, at day 8, significantly more GT was observed in group EGF10 compared to all other groups (p < 0.05). At day 16, in addition to a higher Ki67-immunolabelling, groups EGF1 and EGF10 demonstrated a significant decrease in GT and IR with more deposition of C compared to the other groups (p < 0.05). Conclusion: Application of rhEGF enhanced the early healing of acute oral soft tissue wounds compared to SH, predominantly at concentrations of 1 and 10 μg/g.