Abstract：
Bacterial biofilms are associated with antibiotic resistance and account for approximately 80% of all bacterial infections. In this study, we explored novel nanomaterials for combating bacteria and their biofilms. Artemisinin nano-copper (ANC) was synthesised using a green synthesis strategy, and its shape, size, structure, elemental composition, chemical valence, zeta potential, and conductivity were characterised using transmission electron microscopy, X-ray diffractometer, X-ray photoelectron spectroscopy, zeta potential, and dynamic light scattering (DLS). The results showed that ANC was successfully synthesised utilizing a liquid-phase chemical reduction method using chitosan as a modified protectant and l-ascorbic acid as a green reducing agent. The stability of ANC was evaluated using DLS. The results showed that the particle size of the ANC at different concentrations was comparable to that of the original solution after 7 days of storage, and there was no significant change in PDI (P > 0.05). The antibacterial effects of ANC on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were determined by Disk diffusion and broth dilution methods. The results demonstrated that ANC inhibited and killed E. coli and S. aureus. The effect of ANC on bacterial biofilms was investigated using Crystal Violet staining, scanning electron microscopy, laser confocal microscope, and quantitative PCR. The results showed that ANC treatment was able to destroy bacterial biofilms and downregulate biofilm- and virulence-related genes in E. coli (HlyA, gyrA, and F17) and S. aureus (cna, PVL, ClfA, and femB). Green-synthesised ANC possesses excellent anti-biofilm properties and is expected to exhibit antibacterial and anti-biofilm properties.
摘要：
细菌生物膜与抗生素抗性相关并且占所有细菌感染的约80%。在这项研究中,我们探索了用于对抗细菌及其生物膜的新型纳米材料。采用绿色合成策略合成了青蒿素纳米铜(ANC),和它的形状，尺寸,结构,元素组成,化学价，zeta电位,使用透射电子显微镜对电导率进行表征，X射线衍射仪,X射线光电子能谱,zeta电位,和动态光散射(DLS)。结果表明，以壳聚糖为改性保护剂，L-抗坏血酸为绿色还原剂，利用液相化学还原法成功合成了ANC。使用DLS评价ANC的稳定性。结果表明，不同浓度的ANC在储存7天后的粒径与原始溶液相当，PDI无明显变化(P>0.05)。ANC对大肠杆菌(E.大肠杆菌)和金黄色葡萄球菌(S.金黄色葡萄球菌)通过圆盘扩散和肉汤稀释方法测定。结果表明,ANC抑制并杀死大肠杆菌和金黄色葡萄球菌。使用结晶紫染色研究了ANC对细菌生物膜的影响，扫描电子显微镜，激光共聚焦显微镜,和定量PCR。结果表明，ANC处理能够破坏细菌生物膜并下调大肠杆菌中生物膜和毒力相关基因（HlyA，gyra,和F17)和金黄色葡萄球菌(cna，PVL,ClfA,和femB）。绿色合成的ANC具有优异的抗生物膜性质,并且预期表现出抗菌和抗生物膜性质。
