College of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou 730070, China; New Rural Development Research Institute of Northwest Normal University, Lanzhou 730070, China.
Department of Blood Transfusion Medicine, 940th Hospital of joint service support force of Chinese people's Liberation Army, Lanzhou 730050, China.
Int J Biol Macromol. 2021 Jul 31;183:2326-2336. doi: 10.1016/j.ijbiomac.2021.06.001. Epub 2021 Jun 3.
In this study, a water-soluble bacterial cellulose sulfate (BCS) was prepared with sulfur trioxide pyridine complex (SO3· Py) in a lithium chloride (LiCl)/dimethylacetamide (DMAc) homogeneous solution system using bacterial cellulose (BC). The structural study showed that the value for the degrees of substitution of BCS was 1.23. After modification, the C-6 hydroxyl group of BC was completely substituted and the C-2 and C-3 hydroxyl groups were partially substituted. In an aqueous solution, the BCS existed as a linear polymer with irregular coil conformation, which was consistent with the findings observed using atomic force microscopy. The steady-state shear flow and dynamic viscoelasticity were systematically determined over a range of BCS concentrations (1 %-4 %, w/v) and temperature (5 °C-50 °C). Steady-state flow experiments revealed that BCS exhibited shear thinning behavior, which increased with an increase in concentration and a decrease in temperature. These observations were quantitatively demonstrated using the cross model. Moreover, based on the dynamical viscoelastic properties, we confirmed that BCS was a temperature-sensitive and weak elastic gel, which was somewhere between a dilute solution and an elastic gel. Therefore, considering the special synthetic strategy and rheological behavior, BCS might be used as a renewable material in the field of biological tissue engineering, especially in the manufacture of injectable hydrogels, cell scaffolds, and as a drug carrier.
在这项研究中，采用三氧化硫吡啶复合物（SO3·Py）在氯化锂（LiCl）/二甲基乙酰胺（DMAc）均相溶液体系中，从细菌纤维素（BC）制备了一种水溶性的细菌纤维素硫酸酯（BCS）。结构研究表明，BCS 的取代度值为 1.23。修饰后，BC 的 C-6 羟基完全取代，C-2 和 C-3 羟基部分取代。在水溶液中，BCS 作为一种具有不规则卷曲构象的线性聚合物存在，这与原子力显微镜观察到的结果一致。在 BCS 浓度（1%-4%，w/v）和温度（5°C-50°C）范围内，系统地测定了稳态剪切流动和动态粘弹性。稳态流动实验表明，BCS 表现出剪切变稀行为，其随着浓度的增加和温度的降低而增加。这些观察结果通过交叉模型得到了定量证明。此外，基于动态粘弹性特性，我们证实 BCS 是一种温度敏感的弱弹性凝胶，介于稀溶液和弹性凝胶之间。因此，考虑到特殊的合成策略和流变行为，BCS 可能作为生物组织工程领域的可再生材料使用，特别是在可注射水凝胶、细胞支架的制造以及药物载体方面。
