Preparation, Characterization and Biocompatibility of Chitosan/TEMPO-oxidized Bacterial Cellulose Composite Film for Potential Wound Dressing Applications

In this study, chitosan/oxidized bacterial cellulose (CS/OBC) composite films were produced through impregnation and cross-linking with (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). Bacterial cellulose was selectively oxidized using TEMPO, where a carbonate buffer solution (Na2CO3/NaHCO3) was used to control the pH instead of NaOH. The surface morphology, crystal structure, thermal properties and mechanical strength of OBC and CS/OBC composite films were characterized. Furthermore, antibacterial properties and biocompatibility of OBC and CS/OBC composites were assessed. The results showed that the oxidation process had little impact on the macroscopic morphology and fiber diameter of bacterial cellulose. The crystallization, thermal stability and mechanical properties decreased due to the presence of unstable sodium gluconate in OBC. After compounding with chitosan, the crystallinity and thermal stability of OBC were improved. The mechanical strength increased first and then decreased with the increase of chitosan content. The antibacterial performance of CS/OBC composite films against E. coli was superior than that of S. aureus. When the chitosan content reached 6.6 % or more, the inhibition rate against E. coli and S. aureus was over 90 %. Cell culture studies demonstrated that OBC and the CS/OBC composites had no cytotoxicity. These results indicated that the CS/OBC composite film could be used as a potential wound dressing material.