Effects of Copper Tripeptide on Healing Irradiated Tissues

Abstract

Objective: To evaluate clinical and immunohistochemical effects of topical copper tripeptide (GHK-Cu) on wound healing in an in vivo irradiated rat model.Method: After dorsal radiation to a human-equivalent-dose of 66.67 gray and a recovery period, 2x8-cm cranially based dorsal flaps were created. Twice daily GHK-Cu (test) or Eucerin (control) was applied for 10 days. Animals were euthanized, digital images of flaps were taken, and harvested tissues were stained for vascular endothelial growth factor (VEGF).Results: Thirteen test and 10 control animals were included. Photographs were converted to binary to calculate total pixels within the necrotic region and area of ischemia. The mean ischemic areas were 5.0 cm2 (standard deviation 0.9) for tests and 3.8 cm2 (1.1) for controls, which were significantly different (P = .01). Digitized slides allowed for calculation of the percent of pixels reaching specific brown calorimetric thresholds and for an intensity staining score with higher scores indicating more intense staining. The VEGF mean intensity scores were 0.34 (0.19) for tests and 0.54 (0.41) for controls, which were not significantly different. Unpaired t tests were utilized for statistical analyses.Conclusion: In this study, irradiated soft tissue flaps treated with topical GHK-Cu demonstrated a greater amount of flap ischemia and no difference in VEGF production compared to controls. These findings contrast prior studies suggesting a favorable growth factor environment and an improvement in wound healing with GHK-Cu treatment.