Evaluation of antibacterial activity of chitosan membranes associated to unripe banana peel

The treatment of skin wounds is a worldwide problem due to possible complications of healing process, such as infections, sepsis and even death. Current treatment strategies involves the use of dressings, bandages and topical application of antibiotic to the wound. An ideal dressing should protect against bacterial contamination, while covering the wound. The aim of this study was to investigate the antibacterial activity of chitosan membranes associated to banana peel for potential wound dressing application, since both materials have previously demonstrated antimicrobial properties. The active principles of banana peel were extracted by two methods: decoction and drying. Membranes were prepared by chitosan association with the extracts of first and third days of decoction and with different concentrations of dried extract, by the casting/solvent evaporation techniques. All obtained membranes were uniform, flexible and easily unmolded. Antibacterial activity studies were performed by the Surface Plating technique. Inhibition of bacterial growth was evaluated against two bacteria Escherichia coli and Staphylococcus aureus, usually present in skin wounds. All membranes were able to inhibit S. aureus e E. coli growth by contacting. In addition to contacting inhibition of E. coli growth, an inhibition halo of 0.5 cm diameter was also observed around the chitosan-unripe banana peel membrane prepared with the extract of first day of decoction.