Bacterial cellulose and bacterial cellulose–chitosan membranes for wound dressing applications

Bacterial cellulose (BC) and bacterial cellulose–chitosan (BC–Ch) membranes were successfully produced in large scale. BC was synthesized by Acetobacter xylinum. BC–Ch was prepared by immersing BC in chitosan followed by freeze-drying. The surface morphology of BC and BC–Ch membranes were examined by a scanning electron microscope (SEM). SEM images showed that BC–Ch possessed a denser fibril network with smaller pores than BC. Infrared spectroscopy was used to confirm the incorporation of chitosan in BC–Ch. The swelling behavior, water retention capacity, and mechanical properties of BC and BC–Ch were further evaluated. Results indicated that both membranes maintained proper moisture contents for an extensive period without dehydration. The tensile strength and elongation at break for BC–Ch were slightly lower while the Young's modulus was higher. Cell culture studies demonstrated that BC and BC–Ch had no cytotoxicity. In the antibacterial test, the addition of chitosan in BC showed significant growth inhibition against Escherichia coli and Staphylococcus aureus. The effects of BC and BC–Ch on skin wound healing were assessed by rat models. Histological examinations revealed that wounds treated with BC–Ch epithelialized and regenerated faster than those treated with BC or Tegaderm. Therefore, BC–Ch was considered as a potential candidate for wound dressing materials.