Preparation and characterization of degradable oxidized bacterial cellulose reacted with nitrogen dioxide

Bacterial cellulose (BC) is regarded as one of the most attractive and promising biomaterials in medical applications owing to its high purity and mechanical properties and excellent biocompatibility. In this study, a new kind of degradable oxidized bacterial cellulose (OBC) was prepared by oxidizing BC in the presence of nitrogen dioxide (NO₂), which could be used as a scaffold for tissue engineering and tissue regeneration. The chemical structures, micromorphology, and in vitro degradability of OBC were characterized. The results demonstrated that the oxidation reaction was controllable for tailoring the degree of degradation of BC. After oxidation, the degradation of BC was accelerated, depending on the oxidation time. In the case of oxidation for 12 days, the mass loss rate of OBC increased sharply, up to 45% after being immersed in phosphate buffered saline (PBS) for 60 days, compared with only 10% for original BC in the same condition. The oxidation did not affect the crystal structure of BC, however, changed the morphology of its network. The original dense microfibril network of BC could be gradually degraded and disappeared within a desirable period of time in vitro through controlling the degree of the selective oxidation.