Bacterial Cellulose as a Potential Bone Graft

Each year tissue engineering costs the United States $2 million dollars. Bacterial Cellulose (BC), a hydrogel with a fine fiber network, is produced by the bacterium Acetobacter xylinum that can be used as a protective coating. In contrast to other polymers, BC possesses high tensile strength, high water holding capabilities, and high mechanical properties. The purpose of the current study is to determine if individual fibers of BC can be functionalized with calcium by applying an electric field. BC was grown and calcium was deposited simultaneously using Corn Steep Liquor (CSL) media, with the addition of fructose, in channels 4 cm long x 5 mm wide x 2.5 mm deep. The channels contained platinum electrodes supplying an electric field of 3 to 7.5 volts for 72 hours in the presence of CaCl2. BC pellicles formed and were then examined using the Environmental Scanning Electron Microscope (ESEM). Energy-Dispersive X-ray Spectroscopy (EDS) was also used to determine the composition in each sample. Calcium was found deposited on the BC fibers at 5.5 volts. Lower voltages, such as 4.0 volts, resulted in no calcium deposition on the fibers. The presence of Carboxymethyl Cellulose (CMC) is critical for the calcium deposition. Calcium deposition will occur at 5.5 volts suggesting there may be a specific electric field requirement for calcium deposition on BC.