Effect of addition of aloe vera gel on synthesis of bacterial cellulose film by Acetobacter xylinum

In this thesis, the effects of addition of aloe vera gel on synthesis of bacterial cellulose film by Acetobacter Xylinum was studied due to the unique properties of both aloe vera gel and bacterial cellulose (BC), which might improve the physical and biological properties of the developed film. The mechanical property, equilibrium water content, porous structure, crystallinity index, and the growth of human skin cells on the biosynthesized film with the supplement of aloe vera gel at 0-50 percent-range (v/v) in the culture medium were investigated. From the study, the 30 percent addition of the BC-aloe vera gel showed the best combination for the film formation. The BC-aloe vera film was found to be more strengthen than the BC film. In addition, the interaction between BC fibrils and aloe vera gel could be illustrated from FTIR analysis. Furthermore, both of the mechanical properties and equilibrium water content of the BC-aloe vera film were found to be higher than those of the BC film. The average pore sizes of the BC-aloe vera were smaller than those of the BC film, but the surface area did not much increase from the latter. The crystallinity index of the BC-aloe vera film content at 30 percent was improved to 82.77. Additionally, the BC-aloe vera film had no toxicity and supported the growth and proliferation of human skin cells.

本论文围绕芦荟凝胶与细菌纤维素（bacterial cellulose, BC）各自独特的性能，探究了添加芦荟凝胶对木醋杆菌（Acetobacter Xylinum）合成细菌纤维素膜的影响，以期优化所得膜材的物理与生物学性能。本实验考察了培养基中芦荟凝胶添加量为0~50%（体积比）时，所制备生物合成膜的力学性能、平衡含水率、多孔结构、结晶度指数，以及人皮肤细胞在该膜表面的生长情况。研究结果显示，添加30%芦荟凝胶的细菌纤维素-芦荟复合膜成膜综合性能最优，其力学强度高于纯细菌纤维素膜。此外，傅里叶变换红外光谱（FTIR）分析可揭示细菌纤维素微纤维与芦荟凝胶之间的相互作用。进一步研究发现，该复合膜的力学性能与平衡含水率均优于纯细菌纤维素膜；其平均孔径小于纯细菌纤维素膜，但比表面积较纯膜无显著提升。当芦荟凝胶添加量为30%时，复合膜的结晶度指数提升至82.77。此外，该细菌纤维素-芦荟复合膜无细胞毒性，可有效支持人皮肤细胞的生长与增殖。