新型纳米氧化锌/细菌纤维素复合膜的制备与性能评价

Preparation and properties of a novel zinc oxide nanoparticles/bacterial cellulose composites

目的制备一种新型纳米氧化锌/细菌纤维素复合膜,评价其物理特性和抗菌性能。方法采用二步法制备纳米氧化锌/细菌纤维素复合膜。对细菌纤维素膜(bacterial cellulose membrane,BCM)进行羧基化修饰,然后以此为模板,进行纳米氧化锌(zinc oxide nanoparticles,nZnO)的原位合成,制备成nZnO/BCM复合膜;以BCM为对照,扫描电子显微镜观察nZnO/BCM复合膜的形态及nZnO分布;原子吸收光谱法测定nZnO的含量,评价经高压灭菌和浸提处理后nZnO/BCM复合膜中nZnO的结合稳定性;水蒸气透过率检测评价nZnO/BCM复合膜的透气性;万能材料测试仪检测nZnO/BCM复合膜的抗张强度、断裂伸长率及杨氏模量,评价其力学性能;振荡抑菌实验评价nZnO/BCM对金黄色葡萄球菌和大肠杆菌的抑制作用。结果电镜观察结果显示,二步法合成的nZnO/BCM复合膜的纤维网络呈三维立体结构,其孔隙大小和密度均显著大于单纯BCM;原位合成的nZnO附着于纤维,呈串珠状排列,nZnO直径为30~90 nm。对nZnO/BCM复合膜(含40%nZnO)进行高压灭菌和浸提处理后,其nZnO的脱失率为8.98%。nZnO/BCM复合膜(含40%nZnO)的水蒸气透过率、抗张强度和杨氏模量均显著高于BCM(P<0.05)。nZnO/BCM复合膜(含40%nZnO)对金黄色葡萄球菌和大肠杆菌的抑菌率分别为96.72%、60.14%,显著高于BCM组(P<0.05)。结论二步法制备的nZnO/BCM复合膜具有良好的孔隙率和nZnO结合稳定性,其透气性和物理力学性能得到进一步提高,且对金黄色葡萄球菌和大肠杆菌具有较好的抗菌活性。

Objective To prepare a new wound dressing based on zinc oxide/bacterial cellulose membranes （nZnO/BCM） and determine its properties and antibacterial activity. Methods The assembly of nZnO/BCM was achieved by carboxylation of BCM and in situ synthesis of ZnO nanoparticles using the carboxylated BCM as a template in a non-aqueous polar medium. The nZnO/BCM structure was observed by scanning electron microscopy. The stability of nZnO/BCM was measured by atomic absorption spectrometry. The tensile strength, elongation at break and Young modulus of nZnO/BCM were measured by universal material tester. And the permeability of nZnO/BCM was evaluated by the detection of water vapor transmission. The antibacterial activity of nZnO/BCM was tested using shaking flask method on Staphylococcus aureus and Escherichia coli. Results Our prepared nZnO/BCM had a three-dimensional lattice structure with uniform distribution of ZnO nanospheres in higher density and larger pores when compared with simple BCM. The in situ synthesized nZnO （30-90 nm in diameter） bound to the BCM in beaded arrangement. After the nZnO/BCM （containing 40% nZnO） was autoclaved and leached, 8.98% of nZnO was released. Water vapor transmission rate, tensile strength and Young’s modulus of nZnO/BCM composite membranes （containing 40% nZnO） were significantly higher than those of BCM （P〈0.05）. The inhibitory rates of nZnO/BCM （containing 40% nZnO） against Staphylococcus aureus and Escherichia coli were 96.72% and 60.14%, respectively, significantly higher than those of BCM group （P〈0.05）. Conclusion nZnO/BCM not only possess the uniform distribution of nanoparticles, stable binding, good mechanical properties and proper permeability, but also exhibit good antibacterial activity against Staphylococcus aureus and Escherichia coli.