Conformational and rheological properties of bacterial cellulose sulfate
Conformational and rheological properties of bacterial cellulose sulfate
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细菌硫酸纤维素的构象和流变特性
DOI：
10.1016/j.ijbiomac.2021.06.001
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发表时间：
2021
影响因子：
8.2
通讯作者：
Zengjie Fan
中科院分区：
文献类型：
--
作者：
Shen Song;Xiaoyuan Liu;Ling Ding;Mohamed Aamer Abubaker;Ji Zhang;Yulong Huang;Shengrong Yang;Zengjie Fan
以细菌纤维素（BC）为原料，在氯化锂（LiCl）/二甲基乙酰胺（DMAc）均相溶液体系中，与三氧化硫吡啶络合物（SO 3· Py）反应制备了水溶性细菌纤维素硫酸盐（BCS）。结构研究表明，BCS的取代度为1.23。改性后，BC的C-6羟基被完全取代，C-2和C-3羟基被部分取代。在水溶液中，BCS以线性聚合物的形式存在，具有不规则的卷曲构象，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）的范围内系统地测定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，随着浓度的增加和温度的降低而增加。使用交叉模型定量地证明了这些观察结果。此外，基于动态粘弹性性质，我们证实BCS是一个温度敏感和弱弹性凝胶，这是介于稀溶液和弹性凝胶。因此，考虑到其独特的合成策略和流变特性，BCS有望作为一种可再生材料应用于生物组织工程领域，尤其是可注射水凝胶、细胞支架的制备以及药物载体的制备。
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.