EGF Loaded Chitosan Sponges as Wound Dressing Material

The aim of this study was to prepare and characterize chitosan sponges using epidermal growth factor (EGF) for wound healing. Chitosan sponges were prepared by solvent evaporation (or precipitation) combined with chemical cross-linking techniques. The chitosan polymer was weighed and dissolved in aqueous acetic acid solution (5% v/v) and injected into absolute ethanol containing a cross-linker (ethylene glycol diglycydyl ether). The growth factor (EGF) was loaded into sponges by adding it into the chitosan solution. The EGF loaded chitosan sponges were used in fibroblast cell culture studies to investigate the effects of EGF released on cell proliferation and to determine the effects of the different variables on EGF release; such as, chitosan Mw, cross-linker, the needle injecting the chitosan solution into the precipitation medium, chitosan/EGF ratio and pH of the medium. The swelling of the sponges was higher in the lower molecular weight chitosan, with less cross-linker and using a small diameter injection needle. The swelling increased with decreasing chitosan/EGF ratio and the EGF release rate was increased by increasing the sponge swelling. The cell proliferation (cell growth) increased with increasing swelling ratio.