| Bacterial cellulose (BC) is one of the most abundant natural polymers, produced by Acetobacter xylinum. It can be used as tissue engineering scaffold and artificial skin material, thanks to its excellent biocompatibility, water holding capacity and biodegradability. Extensive functions can be achieved if bacterial cellulose is modified by other chemical agents.In this study, hyaluronic acid (HA) is selected to modify BC. Four different methods are selected to prepare the BC/HA composites:solution immersion method (JP), bio-synthesis method (SF), chemical crosslink method (JL), and gel crosslink method (NJS). These composites are characterized by Field Emission Scanning Electron Microscope (FESEM), Fourier Transform Infrared Spectroscope (FTIR), X-ray Diffraction (XRD), and Thermal Analysis (TGA, DSC). Their properties such as water holding capacity, rehydrations ratio, and tensile strength are tesed. The contents of HA in the four composites increase with the HA concentration in the solution, assayed by Elson-Morgan method. The crystallinities declined accordingly with HA contents in the composites. The Young’s modulus and tensile strengths of JP BC/HA and SF BC/HA increase 11.07% and 18.15% respectely, compared with pristine hydrated BC.Crosslinked BC and HA composites using green, nontoxic crosslink agent 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) are prepared. Influence of temperature and EDC adding mode are analyzed. In conclusion, higher temperature favors to the crosslink reaction. Bands of amide appear on the FTIR spectra of JL composites, and hydrogen bonding between H and O is found to be strengthened. Thermal stabilities of JLC and JLD aren’t influenced by HA; their thermal decomposition temperatures are increased by 2-8℃, in comparison with BC.HA/BC gel is formed when the pH is decreased to the range of 4 and 5. The gel shows good swelling and rehydration properties. It is an elastic material, known from rheological analysis.Both bacterial cellulose and hyaluronic acid are biocompatible materials. They have their own merits and application. Four valuable novel biomaterials have been presented by this paper, and their biocompatibility evaluation is on going. |
