A facile and green strategy for the preparation of porous chitosan-coated cellulose composite membranes for potential applications as wound dressing

A combination of a superior hygroscopic capacity, mechanical strength and antibacterial activity is required for a wound dressing material. To this end, a facile and green technique to prepare porous composite membranes with a sandwich structure is developed here through surface coating of a ready-made cellulose membrane with chitosan. The cellulose membrane endows the composite material with a porous structure, and chitosan provides it with antibacterial performance. No chemical reactions were involved, and no organic solvents except acetic acid were applied throughout the entire process. The structures of the composite membranes were characterized using elemental analysis, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and X-ray diffractometry. Tensile strength, transparence, water vapor transmission rate, swelling behavior, adsorption of BSA, and antibacterial properties were also evaluated. Elemental analysis indicated that chitosan was coated on cellulose successfully and that the coating was tight enough for long-term application. SEM revealed that the porous structure was still maintained after surface coating. In addition, the composite membrane with a good transparence and water vapor transmission rate exhibited enhanced mechanical properties, swelling behavior in water, BSA adsorption capacity, and antibacterial activity against Escherichia coli and Staphylococcus aureus. These results showed that the composite membranes are suitable candidates for biomedical applications as a wound dressing material.