Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.
Department of Macromolecular Science and Engineering, School of Engineering, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Comprehensive Care, School of Dental Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
Mater Sci Eng C Mater Biol Appl. 2019 Jun;99:96-102. doi: 10.1016/j.msec.2019.01.090. Epub 2019 Jan 22.
Among a vast array of biomaterials investigated for tissue engineering applications, bacterial cellulose (BC) has not been evaluated in depth, despite the material's strong potential of applicability in the field of biotechnology. In this study we investigate the effect of sugar concentration and culture duration on physical and mechanical properties of BC. BC was grown in culture media with different glucose concentrations (weight percent) of 1.25%, 2.50%, 5.00%, 10.00%, 15.00% and also in media with fructose concentration of 5.00%. The swelling ratio of harvested BC sheets did not change significantly with concentration of glucose or the type of sugar (fructose vs glucose). Swelling ratio did not change significantly with culture duration either. Cellulose production rate was significantly higher (p < 0.05) at 5.00%wt. glucose concentration compared to other groups. Ultimate tensile strength (309.3 ± 32.8 MPa) and Young's modulus (3.1 ± 0.6 GPa) of BC sheets harvested from the medium with 5.00%wt. glucose concentration were the highest among all treatment groups. Bacterial removal process and testing condition (wet/dry) did not affect the mechanical performance of the bacterial cellulose significantly. X-ray diffraction data demonstrated higher crystallinity for samples cultured in media with 5.00%wt. glucose concentration. Viability/cytotoxicity, proliferation, and cells' metabolic activities demonstrated BC to be biocompatible. Cells attached, spread, and proliferated with time on bacterial cellulose. Results of this study showed 5.00 wt% glucose concentration is the optimum concentration of sugar in media to produce BC with highest strength and modulus compared to other concentration. High mechanical strength along with biocompatibility present bacterial cellulose as an invaluable material for use in tissue engineering of load bearing connective tissues such as tendons and ligaments.
在众多被研究用于组织工程应用的生物材料中，尽管细菌纤维素（BC）在生物技术领域具有很强的应用潜力，但它的研究还不够深入。在本研究中，我们研究了糖浓度和培养时间对 BC 的物理和机械性能的影响。BC 是在不同葡萄糖浓度（重量百分比）为 1.25%、2.50%、5.00%、10.00%、15.00%的培养基中和果糖浓度为 5.00%的培养基中生长的。收获的 BC 片的溶胀比与葡萄糖浓度或糖的类型（果糖与葡萄糖）没有明显变化。溶胀比也与培养时间没有明显变化。与其他组相比，在 5.00%wt.葡萄糖浓度下，纤维素的产率显著更高（p<0.05）。从 5.00%wt.葡萄糖浓度培养基中收获的 BC 片的极限拉伸强度（309.3±32.8MPa）和杨氏模量（3.1±0.6GPa）是所有处理组中最高的。细菌去除过程和测试条件（湿/干）对细菌纤维素的机械性能没有显著影响。X 射线衍射数据表明，在 5.00%wt.葡萄糖浓度的培养基中培养的样品具有更高的结晶度。细胞活力/细胞毒性、增殖和细胞代谢活性表明 BC 具有生物相容性。细胞随时间附着、展开和增殖。这项研究的结果表明，与其他浓度相比，5.00wt%葡萄糖浓度是培养基中产生具有最高强度和模量的 BC 的最佳糖浓度。高机械强度和生物相容性使细菌纤维素成为用于组织工程承重结缔组织（如肌腱和韧带）的宝贵材料。
