Citric acid cross-linked regenerated bacterial cellulose as biodegradable and biocompatible film for food packaging

The global depletion of petrochemical resources, coupled with the environmental problems caused by the widespread use of traditional plastics, have brought more attention to exploring biodegradable materials. However, the high preparation cost and complex manufacturing processes leave us few choices of raw materials of biodegradability. Herein, regenerated bacterial cellulose (RBC) was used to prepare a kind of environmentally-friendly material that degrades rapidly. Further addition of citric acid (CA) enhances its mechanical properties and degradability, resulting in a CA-cross-linked regenerated cellulose (CA-RC) film with a fracture strength of 93.40 MPa and Young's modulus of 4.2 GPa, which behaves better than commercial plastic wrap in food preservation. In addition, the film could be completely degraded in soil within two weeks, of which the biocompatibility is verified by both cell proliferation and hemolysis experiments. The results show that the CA-RC films have great application prospects in food packaging and biomedical materials.