Preparation, Characterization And Biological Evaluation Of Bacterial Cellulose As Tissue Engineering Scaffold

Bacterial cellulose (BC) which is the secretion of Gluconacetobacter xylinum is the only nano-scale cellulose fiber in nature, which is composed of interlacing dsuper-fine network structure made by multi-level micro fiber."Nano-effect" makes it possess high water absorbability, high water-retaining property, high transmissivity to liquid and gas, high degree of crystallization and polymerization, high mechanical strength, especially the ability of in situ processing molding, etc. With the excellent comprehensive properties, bacterial cellulose has been applied in specific fields, especially as biomedical materials. By utilizing the plasticity of bacterial cellulose, various specifications of flat, tubular and patterned bacterial cellulose are prepared as tissue engineering scaffolds, and through the physical, chemical and biological evaluation, it’s proved to be a very promising biomedical material applied in the field of tissue engineering as biomedical materials.At first, Gluconacetobacter xylinum is used as functionalized strain to produce bacterial cellulose. By using its aerobic property, it is cultured in flasks, PDMS molds and agarose patterned molds. With the control of oxygen supply, macrostructure and efficiency of aligned microstructure, flat, tubular and patterned bacterial cellulose which is smooth and uniform can be obtained successfully. These molds give better control of the growing direction and reconstruction of bacterial cellulose.For the next, we completed the characterization of bacterial cellulose produced by the three methods mentioned above. The observation of Fourier Infrared Detection indicate that there are three kinds of absorption peaks representing of C=O bond, C-H bond, and O-H bond respectively. These three functional groups are typical of flat bacterial cellulose; through the observation of X-ray Diffraction, results show that there are diffraction peak at16°and22.75°, which is consistent with typical crystal type I of flat bacterial cellulose; what’s more, the thermogravimetric analysis, shows that the thermo-stability of flat bacterial cellulose is at37℃; with respect to mechanical property, Yang’s modulus of3.94±0.12MPa of tubular bacterial cellulose suggests they’re competent with vessels; through the observation of AFM and SEM, results show that there are significant difference between static culture and ordered manufacture, the latter one is with high orientation to lead cell growing.Finally, the bio-evaluation of bacterial cellulose produced by the three methods mentioned above was performed. In blood compatibility test, the dynamic clotting time in vitro of flat bacterial cellulose is more than60min, the hemolysis rate is less than1%, which was a preliminary prove of outstanding blood compatibility; with CCK-8tests of the culture of seeding cells (including artificial bone, artificial vessel, artificial gut and artificial nerve) in flat, tubular and patterned bacterial cellulose, the results show that the cells can accomplish their living circle on bacterial cellulose, moreover, the staining results indicate that bacterial cellulose can play a role in guiding the cell adhesion, proliferation and migration; in addition, evaluations on animals also suggest that bacterial cellulose is greatly adaptable to the in vivo environment.In all, bacterial cellulose is easy to produce with high efficiency, and its shape can be modified. In the mean time, its physical and chemical properties meet the requirement of targeted organ. Most importantly, from the evaluation of cells and animals, bacterial cellulose shows good biocompatibility. Therefore, it should contribute a lot to the field of biomedical materials and tissue engineering.