Reversal of silver sulfadiazine-impaired wound healing by epidermal growth factor

Silver sulfadiazine (Ag-SD) is a useful antibacterial agent for wound treatment. However, recent findings indicate that the compound delays the wound-healing process. That delay may be reversed by treatment with growth factors. The purpose of this study, was to evaluate the cyto-protective effect of epidermal growth factor (EGF) against Ag-SD treated keratinocytes and to investigate the reversibility of the impaired wound-healing process by the co-supplementation of EGF. Four types of drug-loaded collagen sponge dressings with different concentrations of Ag-SD, EGF and Ag-SD + EGF were prepared. An immortalized keratinocyte, HaCaT cells, were cultured in 35-mm Petri-dish using Dulbecco's Modified Eagle's Minimal Essential Medium (DMEM) with 10% FBS. Cultures were treated with the samples submerged, and viabilities of cultures were evaluated using MTT assay. The wound heal efficacy was evaluated in a partial thickness burn mouse model. Cells treated with EGF showed a cyto-protective effect on 1% Ag-SD treated cells with significant increase in viable cell numbers at concentrations ranging from 1 to 50 microg/ml. The cytotoxicity of Ag-SD impaired wound healing, while the addition of EGF could reverse the impairment. This evidence suggests that EGF is a useful agent in the retardation of wound healing caused by Ag-SD. Therefore, a drug delivery system containing both EGF and Ag-SD, such as that used in the study, may be clinically relevant.