Antibacterial properties and mechanism of biopolymer-based films functionalized by CuO/ZnO nanoparticles against<italic> Escherichia</italic><italic> coli</italic> and Staphylococcus aureus
Antibacterial properties and mechanism of biopolymer-based films functionalized by CuO/ZnO nanoparticles against<italic> Escherichia</italic><italic> coli</italic> and Staphylococcus aureus
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DOI：
10.1016/j.jhazmat.2020.123542
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发表时间：
2021-01-15
影响因子：
13.6
通讯作者：
Sun, Qingjie
中科院分区：
文献类型：
--
作者：
Guan, Guilin;Zhang, Linan;Sun, Qingjie
本研究制备了氧化铜纳米粒子（CuONPs）和氧化锌纳米粒子（ZnONPs）功能化的海藻酸钠（SA）和壳聚糖（CS）组成的纳米复合薄膜（SA-CS@CuO/ZnO），并系统研究了其对大肠杆菌（E. coli）和金黄色葡萄球菌（S. aureus）的抗菌机制。当CuONPs和ZnONPs的含量分别达到1.5%（w/w）和0.5%（w/w）时，SA-CS@CuO/ZnO表现出良好的机械、阻隔和光学性能。此外，ZnONPs的掺入增强了SA-CS@CuO/ZnO的光催化能力，在光照射下产生高水平的活性氧。此外，抗菌结果表明，SA-CS@CuO/ZnO处理在黑暗中对大肠杆菌和金黄色葡萄球菌的生长抑制率高于60%，在光照射下抑制率超过90%。这还表现在细菌细胞结构的不完整，伴随着不稳定的细胞氧化还原平衡和DNA破坏。转录组分析筛选出的差异表达基因的功能主要涉及膜运输、细胞壁与膜合成、细胞抗氧化防御系统、细胞膜和DNA修复系统。细菌转录调控的变化反映了细菌生理活动的紊乱和细胞完整性的丧失，导致细菌细胞的损伤或死亡。
In this study, the nanocomposite film (SA-CS@CuO/ZnO) composed of sodium alginate (SA) and chitosan (CS) functionalized by copper oxide nanoparticles (CuONPs) and zinc oxide nanoparticles (ZnONPs) was fabricated, then its antibacterial mechanisms against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were systematically investigated. When the contents of CuONPs and ZnONPs reached 1.5 % (w/w) and 0.5 % (w/w), respectively, the SA-CS@CuO/ZnO exhibited great mechanical, barrier, and optical properties. Moreover, the incorporation of ZnONPs enhanced the photocatalytic ability of SA-CS@CuO/ZnO, producing a high level of reactive oxygen species under light irradiation. Further, antibacterial results showed that SA-CS@CuO/ZnO treatment inhibited the growth of E. coli and S. aureus higher than 60 % in the dark and exceeded 90 % under light irradiation. This was also manifested in the incompleteness of bacterial cell structure, accompanied by unstable cellular redox balance and DNA disruption. The functions of differentially expressed genes screened by transcriptome analysis were mainly involved in membrane transport, cell wall and membrane synthesis, cellular antioxidant defense system, cell membrane and DNA repair system. The changes in bacterial transcriptional regulation reflected the disturbance in the physiological activities and loss of cell integrity, leading to damage of bacterial cells or death.