Cadexomer-iodine ointment shows stimulation of epidermal regeneration in experimental full-thickness wounds

The use of iodine in wound healing is still controversial. Both wound healing-stimulating effects and toxic effects leading to impaired wound healing have been reported. In order to study the direct effects of iodine on wound healing without interference of infectious pathogens, we investigated wound-healing parameters in noninfected experimental full-thickness wounds in the pig. Topical iodine treatment with an ointment consisting of a combination of iodine and cadexomer (modified starch), was compared with cadexomer ointment, the vehicle without iodine, and with treatment with saline. Treatment lasted for 30 days, followed by 30 days of wound assessment. The rate of epithelialization, wound contraction, systemic iodine absorption and several immunohistochemical markers were evaluated. All 36 wounds healed without macroscopic signs of wound infection and reepithelialized within 21 days. During the first 9 days of treatment, wounds treated with cadexomer-iodine ointment showed significantly more epithelialization than the wounds treated with either cadexomer or saline. In addition, the epidermis of wounds treated with cadexomer-iodine ointment had significantly more epithelial cell layers from day 12 to day 30, and these wounds stained for chondroitin sulphate proteoglycans in the newly formed basement membrane zone, which was not observed with the other treatments. No negative effects of cadexomer-iodine ointment on the formation of granulation tissue, neovascularization or wound contraction were observed. During the treatment systemic iodine absorption was physiologically acceptable. These results showed that treatment with cadexomer-iodine-containing ointment had positive effects on epidermal regeneration during the healing of full-thickness wounds in the pig compared with ointment alone or saline treatment.